The impact of vibrations due to underground trains on Beijing metro line 15 on sensitive equipment in the Institute of Microelectronics of Tsinghua University was discussed to propose a viable solution to mitigate the...The impact of vibrations due to underground trains on Beijing metro line 15 on sensitive equipment in the Institute of Microelectronics of Tsinghua University was discussed to propose a viable solution to mitigate the vibrations.Using the state-of-the-art three-dimensional coupled periodic finite element-boundary element(FE-BE) method,the dynamic track-tunnel-soil interaction model for metro line 15 was used to predict vibrations in the free field at a train speed of 80 km/h.Three types of tracks(direct fixation fasteners,floating slab track and floating ladder track) on the Beijing metro network were considered in the model. For each track,the acceleration response in the free field was obtained.The numerical results show that the influence of vibrations from underground trains on sensitive equipment depends on the track types.At frequencies above 10 Hz,the floating slab track with a natural frequency of 7 Hz can be effective to attenuate the vibrations.展开更多
We discuss what document types account for the calculation of the journal impact factor (JIF) as published in the Journal Citation Reports (JCR). Based on a brief review of articles discussing how to predict JIFs and ...We discuss what document types account for the calculation of the journal impact factor (JIF) as published in the Journal Citation Reports (JCR). Based on a brief review of articles discussing how to predict JIFs and taking data differences between the Web of Science (WoS) and the JCR into account, we make our own predictions. Using data by cited-reference searching for Thomson Scientific's WoS, we predict 2007 impact factors (IFs) for several journals, such as Nature, Science, Learned Publishing and some Library and Information Sciences journals. Based on our colleagues' experiences we expect our predictions to be lower bounds for the official journal impact factors. We explain why it is useful to derive one's own journal impact factor.展开更多
This paper introduces a video application-aware cross-layer framework for joint performance-energy optimization,considering the scenario of multiple users upstreaming real-time Motion JPEG2000 video streams to the acc...This paper introduces a video application-aware cross-layer framework for joint performance-energy optimization,considering the scenario of multiple users upstreaming real-time Motion JPEG2000 video streams to the access point of a WiFi wireless local area network and extends the PHY-MAC run-time cross-layer scheduling strategy that we introduced in (Mangharam et al., 2005; Pollin et al., 2005) to also consider congested network situations where video packets have to be dropped. We show that an optimal solution at PHY-MAC level can be highly suboptimal at application level, and then show that making the cross-layer framework application-aware through a prioritized dropping policy capitalizing on the inherent scalability of Motion JPEG2000 video streams leads to drastic average video quality improvements and inter-user quality variation reductions of as much as 10 dB PSNR, without affecting the overall energy consumption requirements.展开更多
AIM: To assess the impact of bolus volume on the characteristics of small intestinal (SI) impedance signals.METHODS: Concurrent SI manometry-impedance measurements were performed on 12 healthy volunteers to assess the...AIM: To assess the impact of bolus volume on the characteristics of small intestinal (SI) impedance signals.METHODS: Concurrent SI manometry-impedance measurements were performed on 12 healthy volunteers to assess the pattern of proximal jejunal fluid bolus movement over a 14 cm-segment.Each subject was given 34 boluses of normal saline (volume from 1 to 30 mL) via the feeding tube placed immediately above the proximal margin of the studied segment.A bolus-induced impedance event occurred if there was > 12% impedance drop from baseline,over ≥ 3 consecutive segments within 10 s of bolus injection.A minor or major imped-ance event was defined as a duration of impedance drop < 60 s or ≥ 60 s,respectively.RESULTS: The minimum volume required for a detectable SI impedance event was 2 mL.A direct linear relationship between the SI bolus volume and the occurrence of impedance events was noted until SI bolus volume reached 10 mL,a volume which always produced an impedance flow event.There was a moderate correlation between the bolus volume and the duration of impedance drop (r = 0.63,P < 0.0001) and the number of propagated channels (r = 0.50,P < 0.0001).High volume boluses were associated with more major impedance events (≥ 10 mL boluses = 63%,3 mL boluses = 17%,and < 3 mL boluses = 0%,P = 0.02).CONCLUSION: Bolus volume had an impact on the type and length of propagation of SI impedance events and a threshold of 2 mL is required to produce an event.展开更多
By applying tensile stress along 〈100〉 of β phase, the superelastic behavior and stabilization of stress induced martensite (SIM) of Cu 13.4Al 4.0Ni(mass fraction, %) single crystals were studied. The results show ...By applying tensile stress along 〈100〉 of β phase, the superelastic behavior and stabilization of stress induced martensite (SIM) of Cu 13.4Al 4.0Ni(mass fraction, %) single crystals were studied. The results show that the pseudo yield stress decreases with the increase of cycling number, and keeping load isothermally has an effect on stabilization of SIM. Previous thermal cycling between ( M s-20 ℃) and ( A f+20 ℃) promotes the superelasticity and the stabilization of SIM as well; the pre thermal cycling also reduces the pseudo yield stress. However, once the stabilization of SIM is produced, it can be destabilized by either the afterwards thermal cooling heating cycling or load and immediately unload cycling in ( A f~ M d). Isothermal treatment in ( A f~ M d) brings restabilization of SIM. The maximum superelastic value from β → β ′ 1(18 R ) is 9% for the studied single crystal. When test temperature is in A f~( A f+50 ℃) and stress is in 0~350 MPa, the superelastic behavior exist. [展开更多
With a random sample of 10 JCR(Science) subject areas it is shown that the 2-year and the 5-year impact factor of journals lead statistically to the same ranking per category. Yet in a majority of cases, the 5-year im...With a random sample of 10 JCR(Science) subject areas it is shown that the 2-year and the 5-year impact factor of journals lead statistically to the same ranking per category. Yet in a majority of cases, the 5-year impact factor is larger than the 2-year one.展开更多
Inspired by our previous studies to discover novel human immunodeficiency virus-1(HIV-1)nonnucleoside reverse transcriptase inhibitors(NNRTIs)by targeting the tolerant region II of the NNRTIs binding pocket(NNIBP),a s...Inspired by our previous studies to discover novel human immunodeficiency virus-1(HIV-1)nonnucleoside reverse transcriptase inhibitors(NNRTIs)by targeting the tolerant region II of the NNRTIs binding pocket(NNIBP),a series of novel benzo[4,5]thieno[2,3-d]pyrimidine derivatives were designed through structure-based drug design as novel potent HIV-1 NNRTIs.The results showed that compound16b was the most active inhibitor,exhibiting 50% effective concentration(EC50)values from 0.021μmol/L to 0.298μmol/L against wild-type(WT)and a panel of NNRTIs-resistant HIV-1 strains.Moreover,16b was demonstrated with a significantly low 50% cytotoxicity concentration(CC_(50))value(>200μmol/L)and high selectivity index(SI)values.In addition,16b yielded moderate reverse transcriptase(RT)enzyme inhibition with a 50% inhibition concentration(IC_(50))value of 0.183μmol/L,which demonstrated that it acted as HIV-1 NNRTIs.The binding mode of 16b with RT was also illustrated via molecular docking.Overall,this work provided a novel lead compound for developing potent HIV-1 NNRTIs.展开更多
With our continuous endeavors in seeking potent anti-HIV-1 agents,we reported here the discovery,biological characterization,and druggability evaluation of a class of nonnucleoside reverse transcriptase inhibitors.To ...With our continuous endeavors in seeking potent anti-HIV-1 agents,we reported here the discovery,biological characterization,and druggability evaluation of a class of nonnucleoside reverse transcriptase inhibitors.To fully explore the chemical space of the NNRTI-binding pocket,novel series of dihydrothiopyrano[3,2-d]pyrimidines were developed by employing the structure-based design strategy.Most of the derivatives were endowed with prominent antiviral activities against HIV-1 wild-type and resistant strains at nanomolar levels.Among them,compound 23h featuring the aminopiperidine moiety was identified as the most potent inhibitor,with EC50values ranging from 3.43 to 21.4 nmol/L.Especially,for the challenging double-mutants F227L+V106A and K103N+Y181C,23h exhibited 2.3-to 14.5-fold more potent activity than the first-line drugs efavirenz and etravirine.Besides,the resistance profiles of 23h achieved remarkable improvement compared to efavirenz and etravirine.The binding target of 23h was further confirmed to be HIV-1 reverse transcriptase.Molecular modeling studies were also performed to elucidate the biological evaluation results and give guidance for the optimization campaign.Furthermore,no apparent inhibition of the major CYP450 enzymes and hERG channel was observed for 23h.Most importantly,23h was characterized by good pharmacokinetic properties and excellent safety in vivo.Collectively,23h holds great promise as a potential candidate for its effective antiviral efficacy and favorable drug-like profiles.展开更多
本文利用Web of Science数据库,构建出数学、电化学、信息计量学和传播学4个领域的高频共关键词网络。用于反映领域核心知识。此类网络以关键词为节点,当两个关键词用于同一论文中时就形成节点之间的连接。核心/边缘分析和网络分析...本文利用Web of Science数据库,构建出数学、电化学、信息计量学和传播学4个领域的高频共关键词网络。用于反映领域核心知识。此类网络以关键词为节点,当两个关键词用于同一论文中时就形成节点之间的连接。核心/边缘分析和网络分析参数表明核心关键词数量增长速度低于关键词总量增速。依据核心关键词表达核心知识概念的逻辑,推论特定知识领域中稳定的核心概念及其共现网络反映了该领域相对稳定的核心知识及其结构。展开更多
一论文集的一般P-C矩阵由论文数据和引文数据两部分组成。基于一般P-C矩阵并引入“等时性”概念,我们创建了关键变量Ck。Ck表示的是不同年份发表的论文在各自发表后第k年的引文数量的平均值。借助Ck可以构建R族科学发展节律指标,定义...一论文集的一般P-C矩阵由论文数据和引文数据两部分组成。基于一般P-C矩阵并引入“等时性”概念,我们创建了关键变量Ck。Ck表示的是不同年份发表的论文在各自发表后第k年的引文数量的平均值。借助Ck可以构建R族科学发展节律指标,定义为引文观察值和引文期望值的比值,用于反映科学发展的节律。R族指标包括4项指标:①指标R——被引年视角加三角形引文窗口;②指标R’——被引年视角加平行四边形引文窗口;③指标r——引用年视角加三角形引文窗121;④指标r’——引用年视角加平行四边形引文窗口。以Journal of Documentation为例,本文具体说明了R族序列的计算和R族指标的应用。展开更多
The fluvial geochemistry of the mainstream and tributaries of the Zengjiang River was investigated,and the mass balance approach and deduction methods were used to estimate the uptake of atmospheric CO2 through rock c...The fluvial geochemistry of the mainstream and tributaries of the Zengjiang River was investigated,and the mass balance approach and deduction methods were used to estimate the uptake of atmospheric CO2 through rock chemical weathering.The results showed that the chemical runoff mainly consisted of HCO3-,Ca2+,Na+,and dissolved Si,and that silicate mineral weathering was significant,but carbonate mineral weathering was a minor source of dissolved loads in the Zengjiang River basin because of the low amount of interlayered carbonate rock strata in the catchment.The ion composition indicated that atmospheric CO2 was the primary erosive agent for rock chemical weathering in the Zengjiang River basin.The CO2 consumption fluxes caused by rock chemical weathering were(3.50-3.81) × 105 mol km-2 a-1,which is just lower than that in tropical and subtropical basalt and carbonate regions,and is much higher than that in temperate and cold-temperate regions,indicating that surficial chemical weathering processes in the humid and hot monsoon current influencing the low-middle latitude zone of the Northern Hemisphere constitutes a significant carbon sink in the global biogeochemical cycle.展开更多
Open retropubic radical prostatectomy has been the“gold standard”treatment for locally confined prostate cancer(PCa)but in recent years minimal invasive techniques as laparoscopy and robot-assisted prostatectomy hav...Open retropubic radical prostatectomy has been the“gold standard”treatment for locally confined prostate cancer(PCa)but in recent years minimal invasive techniques as laparoscopy and robot-assisted prostatectomy have become widely available.The trifecta of the surgical treatment of PCa is cancer control,the preservation of continence,and erectile potency.Over the years the complication rates of radical prostatectomy have become very limited with improved cancer control and better functional results.We review the indications and the surgical technique of radical prostatectomy,be it open or laparoscopic,eventually robot-assisted as well as the pre-and postoperative measures and the surgery-related consequences.展开更多
基金Projects(50538010,50848046) supported by the National Natural Science Foundation of ChinaProject(BIL07/07) supported by the Research Council of K.U.Leuven and the National Natural Science Foundation of China
文摘The impact of vibrations due to underground trains on Beijing metro line 15 on sensitive equipment in the Institute of Microelectronics of Tsinghua University was discussed to propose a viable solution to mitigate the vibrations.Using the state-of-the-art three-dimensional coupled periodic finite element-boundary element(FE-BE) method,the dynamic track-tunnel-soil interaction model for metro line 15 was used to predict vibrations in the free field at a train speed of 80 km/h.Three types of tracks(direct fixation fasteners,floating slab track and floating ladder track) on the Beijing metro network were considered in the model. For each track,the acceleration response in the free field was obtained.The numerical results show that the influence of vibrations from underground trains on sensitive equipment depends on the track types.At frequencies above 10 Hz,the floating slab track with a natural frequency of 7 Hz can be effective to attenuate the vibrations.
文摘We discuss what document types account for the calculation of the journal impact factor (JIF) as published in the Journal Citation Reports (JCR). Based on a brief review of articles discussing how to predict JIFs and taking data differences between the Web of Science (WoS) and the JCR into account, we make our own predictions. Using data by cited-reference searching for Thomson Scientific's WoS, we predict 2007 impact factors (IFs) for several journals, such as Nature, Science, Learned Publishing and some Library and Information Sciences journals. Based on our colleagues' experiences we expect our predictions to be lower bounds for the official journal impact factors. We explain why it is useful to derive one's own journal impact factor.
文摘This paper introduces a video application-aware cross-layer framework for joint performance-energy optimization,considering the scenario of multiple users upstreaming real-time Motion JPEG2000 video streams to the access point of a WiFi wireless local area network and extends the PHY-MAC run-time cross-layer scheduling strategy that we introduced in (Mangharam et al., 2005; Pollin et al., 2005) to also consider congested network situations where video packets have to be dropped. We show that an optimal solution at PHY-MAC level can be highly suboptimal at application level, and then show that making the cross-layer framework application-aware through a prioritized dropping policy capitalizing on the inherent scalability of Motion JPEG2000 video streams leads to drastic average video quality improvements and inter-user quality variation reductions of as much as 10 dB PSNR, without affecting the overall energy consumption requirements.
基金Supported by The National Health and Medical Research Council of Australia
文摘AIM: To assess the impact of bolus volume on the characteristics of small intestinal (SI) impedance signals.METHODS: Concurrent SI manometry-impedance measurements were performed on 12 healthy volunteers to assess the pattern of proximal jejunal fluid bolus movement over a 14 cm-segment.Each subject was given 34 boluses of normal saline (volume from 1 to 30 mL) via the feeding tube placed immediately above the proximal margin of the studied segment.A bolus-induced impedance event occurred if there was > 12% impedance drop from baseline,over ≥ 3 consecutive segments within 10 s of bolus injection.A minor or major imped-ance event was defined as a duration of impedance drop < 60 s or ≥ 60 s,respectively.RESULTS: The minimum volume required for a detectable SI impedance event was 2 mL.A direct linear relationship between the SI bolus volume and the occurrence of impedance events was noted until SI bolus volume reached 10 mL,a volume which always produced an impedance flow event.There was a moderate correlation between the bolus volume and the duration of impedance drop (r = 0.63,P < 0.0001) and the number of propagated channels (r = 0.50,P < 0.0001).High volume boluses were associated with more major impedance events (≥ 10 mL boluses = 63%,3 mL boluses = 17%,and < 3 mL boluses = 0%,P = 0.02).CONCLUSION: Bolus volume had an impact on the type and length of propagation of SI impedance events and a threshold of 2 mL is required to produce an event.
文摘By applying tensile stress along 〈100〉 of β phase, the superelastic behavior and stabilization of stress induced martensite (SIM) of Cu 13.4Al 4.0Ni(mass fraction, %) single crystals were studied. The results show that the pseudo yield stress decreases with the increase of cycling number, and keeping load isothermally has an effect on stabilization of SIM. Previous thermal cycling between ( M s-20 ℃) and ( A f+20 ℃) promotes the superelasticity and the stabilization of SIM as well; the pre thermal cycling also reduces the pseudo yield stress. However, once the stabilization of SIM is produced, it can be destabilized by either the afterwards thermal cooling heating cycling or load and immediately unload cycling in ( A f~ M d). Isothermal treatment in ( A f~ M d) brings restabilization of SIM. The maximum superelastic value from β → β ′ 1(18 R ) is 9% for the studied single crystal. When test temperature is in A f~( A f+50 ℃) and stress is in 0~350 MPa, the superelastic behavior exist. [
基金supported by the National Natural Science Foundation of China(Grant No.70673019)
文摘With a random sample of 10 JCR(Science) subject areas it is shown that the 2-year and the 5-year impact factor of journals lead statistically to the same ranking per category. Yet in a majority of cases, the 5-year impact factor is larger than the 2-year one.
基金financial support from the National Natural Science Foundation of China(NSFC,Nos.81973181,82273773)Shandong Provincial Natural Science Foundation(Nos.ZR2020YQ61,ZR2020JQ31)Qilu Young Scholars Program of Shandong University and Taishan Scholar Program at Shandong Province。
文摘Inspired by our previous studies to discover novel human immunodeficiency virus-1(HIV-1)nonnucleoside reverse transcriptase inhibitors(NNRTIs)by targeting the tolerant region II of the NNRTIs binding pocket(NNIBP),a series of novel benzo[4,5]thieno[2,3-d]pyrimidine derivatives were designed through structure-based drug design as novel potent HIV-1 NNRTIs.The results showed that compound16b was the most active inhibitor,exhibiting 50% effective concentration(EC50)values from 0.021μmol/L to 0.298μmol/L against wild-type(WT)and a panel of NNRTIs-resistant HIV-1 strains.Moreover,16b was demonstrated with a significantly low 50% cytotoxicity concentration(CC_(50))value(>200μmol/L)and high selectivity index(SI)values.In addition,16b yielded moderate reverse transcriptase(RT)enzyme inhibition with a 50% inhibition concentration(IC_(50))value of 0.183μmol/L,which demonstrated that it acted as HIV-1 NNRTIs.The binding mode of 16b with RT was also illustrated via molecular docking.Overall,this work provided a novel lead compound for developing potent HIV-1 NNRTIs.
基金financial support from the National Natural Science Foundation of China(NSFC nos.81973181 and 81903453)Science Foundation for Outstanding Young Scholars of Shandong Province(ZR2020JQ31,China)+6 种基金Science Foundation for Excellent Young Scholars of Shandong Province(ZR2020YQ61,China)Foreign Cultural and Educational Experts Project(GXL20200015001,China)China Postdoctoral Science Foundation(2022M721948)Shandong Province Natural Science Foundation for Youths(ZR2023QH217,China)Natural Science Foundation of Jiangsu Province(BK20230252,China)Qilu Young Scholars Program of Shandong UniversityTaishan Scholar Program at Shandong Province。
文摘With our continuous endeavors in seeking potent anti-HIV-1 agents,we reported here the discovery,biological characterization,and druggability evaluation of a class of nonnucleoside reverse transcriptase inhibitors.To fully explore the chemical space of the NNRTI-binding pocket,novel series of dihydrothiopyrano[3,2-d]pyrimidines were developed by employing the structure-based design strategy.Most of the derivatives were endowed with prominent antiviral activities against HIV-1 wild-type and resistant strains at nanomolar levels.Among them,compound 23h featuring the aminopiperidine moiety was identified as the most potent inhibitor,with EC50values ranging from 3.43 to 21.4 nmol/L.Especially,for the challenging double-mutants F227L+V106A and K103N+Y181C,23h exhibited 2.3-to 14.5-fold more potent activity than the first-line drugs efavirenz and etravirine.Besides,the resistance profiles of 23h achieved remarkable improvement compared to efavirenz and etravirine.The binding target of 23h was further confirmed to be HIV-1 reverse transcriptase.Molecular modeling studies were also performed to elucidate the biological evaluation results and give guidance for the optimization campaign.Furthermore,no apparent inhibition of the major CYP450 enzymes and hERG channel was observed for 23h.Most importantly,23h was characterized by good pharmacokinetic properties and excellent safety in vivo.Collectively,23h holds great promise as a potential candidate for its effective antiviral efficacy and favorable drug-like profiles.
文摘本文利用Web of Science数据库,构建出数学、电化学、信息计量学和传播学4个领域的高频共关键词网络。用于反映领域核心知识。此类网络以关键词为节点,当两个关键词用于同一论文中时就形成节点之间的连接。核心/边缘分析和网络分析参数表明核心关键词数量增长速度低于关键词总量增速。依据核心关键词表达核心知识概念的逻辑,推论特定知识领域中稳定的核心概念及其共现网络反映了该领域相对稳定的核心知识及其结构。
文摘一论文集的一般P-C矩阵由论文数据和引文数据两部分组成。基于一般P-C矩阵并引入“等时性”概念,我们创建了关键变量Ck。Ck表示的是不同年份发表的论文在各自发表后第k年的引文数量的平均值。借助Ck可以构建R族科学发展节律指标,定义为引文观察值和引文期望值的比值,用于反映科学发展的节律。R族指标包括4项指标:①指标R——被引年视角加三角形引文窗口;②指标R’——被引年视角加平行四边形引文窗口;③指标r——引用年视角加三角形引文窗121;④指标r’——引用年视角加平行四边形引文窗口。以Journal of Documentation为例,本文具体说明了R族序列的计算和R族指标的应用。
基金supported by the National Natural Science Foundation of China (40871143, 41071054 and 40671027)an Open Fund of the China Institute of Water Resources and Hydropower Researchthe Guangdong Natural Science Foundation (7003669)
文摘The fluvial geochemistry of the mainstream and tributaries of the Zengjiang River was investigated,and the mass balance approach and deduction methods were used to estimate the uptake of atmospheric CO2 through rock chemical weathering.The results showed that the chemical runoff mainly consisted of HCO3-,Ca2+,Na+,and dissolved Si,and that silicate mineral weathering was significant,but carbonate mineral weathering was a minor source of dissolved loads in the Zengjiang River basin because of the low amount of interlayered carbonate rock strata in the catchment.The ion composition indicated that atmospheric CO2 was the primary erosive agent for rock chemical weathering in the Zengjiang River basin.The CO2 consumption fluxes caused by rock chemical weathering were(3.50-3.81) × 105 mol km-2 a-1,which is just lower than that in tropical and subtropical basalt and carbonate regions,and is much higher than that in temperate and cold-temperate regions,indicating that surficial chemical weathering processes in the humid and hot monsoon current influencing the low-middle latitude zone of the Northern Hemisphere constitutes a significant carbon sink in the global biogeochemical cycle.
文摘Open retropubic radical prostatectomy has been the“gold standard”treatment for locally confined prostate cancer(PCa)but in recent years minimal invasive techniques as laparoscopy and robot-assisted prostatectomy have become widely available.The trifecta of the surgical treatment of PCa is cancer control,the preservation of continence,and erectile potency.Over the years the complication rates of radical prostatectomy have become very limited with improved cancer control and better functional results.We review the indications and the surgical technique of radical prostatectomy,be it open or laparoscopic,eventually robot-assisted as well as the pre-and postoperative measures and the surgery-related consequences.