Marine sponges of the genus Stelletta are well known as rich sources of diverse and complex biologically relevant natural products, including alkaloids, terpenoids, peptides, lipids, and steroids. Some of these metabo...Marine sponges of the genus Stelletta are well known as rich sources of diverse and complex biologically relevant natural products, including alkaloids, terpenoids, peptides, lipids, and steroids. Some of these metabolites, with novel structures and promising biological activities, have attracted a lot of attention from chemists seeking to perform their total synthesis in parallel to intensive biological studies towards new drug leads. In this review, we summarized the distribution of the chemically investigated Stelletta sponges, the isolation, synthesis and biological activities of their secondary metabolites, covering the literature from 1982 to early 2018.展开更多
Heart monitoring improves life quality.Electrocardiograms(ECGs or EKGs)detect heart irregularities.Machine learning algorithms can create a few ECG diagnosis processing methods.The first method uses raw ECG and time-s...Heart monitoring improves life quality.Electrocardiograms(ECGs or EKGs)detect heart irregularities.Machine learning algorithms can create a few ECG diagnosis processing methods.The first method uses raw ECG and time-series data.The second method classifies the ECG by patient experience.The third technique translates ECG impulses into Q waves,R waves and S waves(QRS)features using richer information.Because ECG signals vary naturally between humans and activities,we will combine the three feature selection methods to improve classification accuracy and diagnosis.Classifications using all three approaches have not been examined till now.Several researchers found that Machine Learning(ML)techniques can improve ECG classification.This study will compare popular machine learning techniques to evaluate ECG features.Four algorithms—Support Vector Machine(SVM),Decision Tree,Naive Bayes,and Neural Network—compare categorization results.SVM plus prior knowledge has the highest accuracy(99%)of the four ML methods.QRS characteristics failed to identify signals without chaos theory.With 99.8%classification accuracy,the Decision Tree technique outperformed all previous experiments.展开更多
In this work, the Styrene-butadiene rubber (SBR)/lead oxide and the Styrene-butadiene rubber (SBR)/lead nitrate composites were prepared as gamma-radiation shielding materials. The investigated materials were prepared...In this work, the Styrene-butadiene rubber (SBR)/lead oxide and the Styrene-butadiene rubber (SBR)/lead nitrate composites were prepared as gamma-radiation shielding materials. The investigated materials were prepared with three different weight percentage of lead oxide and lead nitrate (30, 50 and 70 wt%). The mass attenuation coefficients (μ<sub>m</sub>) for all composite samples were measured experimentally at 511 and 661.6 keV photon energies. The measurements were made by performing transmission experiments with a 3'' × 3'' NaI (Tl) scintillation detector, which had an energy resolution of 7% at 0.662 MeV for the gamma-rays from the decay of <sup>137</sup>Cs. The effective atomic numbers (Z<sub>eff</sub>) and the effective electron densities (N<sub>eff</sub>) were determined experimentally. Also they were determined theoretically using the obtained μ<sub>m</sub> values for the studied composites samples by WinXCom program. The obtained results show that the experimental values of the composites are found to be in a good agreement with the theoretical values. It is recognized that the mass attenuation coefficient (μ<sub>m</sub>), effective atomic numbers (Z<sub>eff</sub>) and the effective electron densities (N<sub>eff</sub>) are increased in the composite samples which contain lead oxides than which contain lead nitrates. Finally, the Styrene-butadiene rubber (SBR)/lead oxide is better than Styrene-butadiene rubber (SBR)/lead nitrate polymer as gamma radiation shielding.展开更多
Cell membrane camouflaged nanoparticles have been widely used in the field of drug leads discovery attribute to their unique biointerface targeting function.However,random orientation of cell membrane coating does not...Cell membrane camouflaged nanoparticles have been widely used in the field of drug leads discovery attribute to their unique biointerface targeting function.However,random orientation of cell membrane coating does not guarantee effective and appropriate binding of drugs to specific sites,especially when applied to intracellular regions of transmembrane proteins.Bioorthogonal reactions have been rapidly developed as a specific and reliable method for cell membrane functionalization without disturbing living biosystem.Herein,inside-out cell membrane camouflaged magnetic nanoparticles(IOCMMNPs)were accurately constructed via bioorthogonal reactions to screen small molecule inhibitors targeting intracellular tyrosine kinase domain of vascular endothelial growth factor recptor-2.Azide functionalized cell membrane acted as a platform for specific covalently coupling with alkynyl functionalized magnetic Fe_(3)O_(4)nanoparticles to prepare IOCMMNPs.The inside-out orientation of cell membrane was successfully verified by immunogold staining and sialic acid quantification assay.Ultimately,two compounds,senkyunolide A and ligustilidel,were successfully captured,and their potential antiproliferative activities were further testified by pharmacological experiments.It is anticipated that the proposed inside-out cell membrane coating strategy endows tremendous versatility for engineering cell membrane camouflaged nanoparticles and promotes the development of drug leads discovery platforms.展开更多
The transient plane source(TPS)method is developed recently to measure the thermal conductivity of materials.In the measurement,the heating power is influenced by the heat which is transferred via the probe electrical...The transient plane source(TPS)method is developed recently to measure the thermal conductivity of materials.In the measurement,the heating power is influenced by the heat which is transferred via the probe electrical leads.This fact further influences the measurement accuracy of thermal conductivity.To solve this problem,the influence of heat loss through the electrical leads on the heating power is studied theoretically.The mathematical formula of heat loss is deduced,and the corresponding correction model is presented.A series of measurement experiments on different materials have been conducted by using the hot disk thermal constant analyzer.The results show that the influence of the heat loss on the measurement is sensitive to different test materials and probes with different sizes.When the thermal conductivity of the material is greater than 0.2 W/(m·K),the influence of the heat loss is less than 0.16%,which can be ignored.As to the lower thermal conductivity materials,it is necessary to compensate the heat loss through the electrical leads,and the accuracy of thermal conductivity measurement can be effectively improved.展开更多
Background The need for transvenous lead extraction procedures of coronary sinus （CS） leads is increasing due to rising numbers of implanted cardiac resynchronization therapy devices during the past decade. Methods ...Background The need for transvenous lead extraction procedures of coronary sinus （CS） leads is increasing due to rising numbers of implanted cardiac resynchronization therapy devices during the past decade. Methods From January 2009 to June 2013, 27 CS leads were scheduled for extraction in 27 patients （mean age （63.1±14.6） years）. Indications for lead extraction were infection in 13 and lead dysfunction in 14 cases. Isolated extraction of CS leads was performed in eight, extraction of multiple leads in 19 cases. Among leads with an implant time of 〉12 months （n=19） mean implant duration （MID） was （46.4±15.2） （12-76） months. Groups were formed depending on infectious or non-infectious indications （INF vs. Non-INF）, and the use or non-use of extraction tools （ET1 vs. ET0）. Results Among patients with an implant duration of 〉12 months, complete procedural success was 94.7% and clinical success 100%. Operative mortality was zero. In the INF versus NON-INF groups complete procedural success （100% vs. 91.7%, P=0.43）, mean number of required extraction tools （0.7 （0-2） vs. 0.9 （0-3）, P=0.65） and MID （49.1±15.0 vs. 44.7±15.8, P=0.83） did not differ significantly. Comparing the groups ET1 and ET0 showed no significant differences in complications （n=l vs. n=l, P=-0.81） and MID （47.0±17.5 vs. 45.5±12.6, P=0.71）. Conclusions In specialized centers transvenous lead extraction of coronary sinus leads with a mean implant duration of almost four years can be performed safely and effectively. Neither non-infectious indications nor the use of extraction tools negatively affected the outcome of the procedure.展开更多
基金supported by the National Natural Science Foundation of China (NSFC, Nos. 41676073, 81520108028)the National Natural Science Foundation of China /Centre National de la Recherché Scientifique (NSFC/CNRS) joint project (No. 81811530284)+2 种基金"Youth Innovation Promotion Association" (No. 2016258) from Chinese Academy of Sciencesthe SA-SIBS Scholarship Programthe National Key Research and Development Program (2017YFE0103100)
文摘Marine sponges of the genus Stelletta are well known as rich sources of diverse and complex biologically relevant natural products, including alkaloids, terpenoids, peptides, lipids, and steroids. Some of these metabolites, with novel structures and promising biological activities, have attracted a lot of attention from chemists seeking to perform their total synthesis in parallel to intensive biological studies towards new drug leads. In this review, we summarized the distribution of the chemically investigated Stelletta sponges, the isolation, synthesis and biological activities of their secondary metabolites, covering the literature from 1982 to early 2018.
基金The authors extend their appreciation to the Deanship of Scientific Research at King Khalid University for funding this work through Large Groups(Grant Number RGP.2/246/44),B.B.,and https://www.kku.edu.sa/en.
文摘Heart monitoring improves life quality.Electrocardiograms(ECGs or EKGs)detect heart irregularities.Machine learning algorithms can create a few ECG diagnosis processing methods.The first method uses raw ECG and time-series data.The second method classifies the ECG by patient experience.The third technique translates ECG impulses into Q waves,R waves and S waves(QRS)features using richer information.Because ECG signals vary naturally between humans and activities,we will combine the three feature selection methods to improve classification accuracy and diagnosis.Classifications using all three approaches have not been examined till now.Several researchers found that Machine Learning(ML)techniques can improve ECG classification.This study will compare popular machine learning techniques to evaluate ECG features.Four algorithms—Support Vector Machine(SVM),Decision Tree,Naive Bayes,and Neural Network—compare categorization results.SVM plus prior knowledge has the highest accuracy(99%)of the four ML methods.QRS characteristics failed to identify signals without chaos theory.With 99.8%classification accuracy,the Decision Tree technique outperformed all previous experiments.
文摘In this work, the Styrene-butadiene rubber (SBR)/lead oxide and the Styrene-butadiene rubber (SBR)/lead nitrate composites were prepared as gamma-radiation shielding materials. The investigated materials were prepared with three different weight percentage of lead oxide and lead nitrate (30, 50 and 70 wt%). The mass attenuation coefficients (μ<sub>m</sub>) for all composite samples were measured experimentally at 511 and 661.6 keV photon energies. The measurements were made by performing transmission experiments with a 3'' × 3'' NaI (Tl) scintillation detector, which had an energy resolution of 7% at 0.662 MeV for the gamma-rays from the decay of <sup>137</sup>Cs. The effective atomic numbers (Z<sub>eff</sub>) and the effective electron densities (N<sub>eff</sub>) were determined experimentally. Also they were determined theoretically using the obtained μ<sub>m</sub> values for the studied composites samples by WinXCom program. The obtained results show that the experimental values of the composites are found to be in a good agreement with the theoretical values. It is recognized that the mass attenuation coefficient (μ<sub>m</sub>), effective atomic numbers (Z<sub>eff</sub>) and the effective electron densities (N<sub>eff</sub>) are increased in the composite samples which contain lead oxides than which contain lead nitrates. Finally, the Styrene-butadiene rubber (SBR)/lead oxide is better than Styrene-butadiene rubber (SBR)/lead nitrate polymer as gamma radiation shielding.
基金the National Natural Science Foundation of China(No.82073807)。
文摘Cell membrane camouflaged nanoparticles have been widely used in the field of drug leads discovery attribute to their unique biointerface targeting function.However,random orientation of cell membrane coating does not guarantee effective and appropriate binding of drugs to specific sites,especially when applied to intracellular regions of transmembrane proteins.Bioorthogonal reactions have been rapidly developed as a specific and reliable method for cell membrane functionalization without disturbing living biosystem.Herein,inside-out cell membrane camouflaged magnetic nanoparticles(IOCMMNPs)were accurately constructed via bioorthogonal reactions to screen small molecule inhibitors targeting intracellular tyrosine kinase domain of vascular endothelial growth factor recptor-2.Azide functionalized cell membrane acted as a platform for specific covalently coupling with alkynyl functionalized magnetic Fe_(3)O_(4)nanoparticles to prepare IOCMMNPs.The inside-out orientation of cell membrane was successfully verified by immunogold staining and sialic acid quantification assay.Ultimately,two compounds,senkyunolide A and ligustilidel,were successfully captured,and their potential antiproliferative activities were further testified by pharmacological experiments.It is anticipated that the proposed inside-out cell membrane coating strategy endows tremendous versatility for engineering cell membrane camouflaged nanoparticles and promotes the development of drug leads discovery platforms.
文摘The transient plane source(TPS)method is developed recently to measure the thermal conductivity of materials.In the measurement,the heating power is influenced by the heat which is transferred via the probe electrical leads.This fact further influences the measurement accuracy of thermal conductivity.To solve this problem,the influence of heat loss through the electrical leads on the heating power is studied theoretically.The mathematical formula of heat loss is deduced,and the corresponding correction model is presented.A series of measurement experiments on different materials have been conducted by using the hot disk thermal constant analyzer.The results show that the influence of the heat loss on the measurement is sensitive to different test materials and probes with different sizes.When the thermal conductivity of the material is greater than 0.2 W/(m·K),the influence of the heat loss is less than 0.16%,which can be ignored.As to the lower thermal conductivity materials,it is necessary to compensate the heat loss through the electrical leads,and the accuracy of thermal conductivity measurement can be effectively improved.
文摘Background The need for transvenous lead extraction procedures of coronary sinus （CS） leads is increasing due to rising numbers of implanted cardiac resynchronization therapy devices during the past decade. Methods From January 2009 to June 2013, 27 CS leads were scheduled for extraction in 27 patients （mean age （63.1±14.6） years）. Indications for lead extraction were infection in 13 and lead dysfunction in 14 cases. Isolated extraction of CS leads was performed in eight, extraction of multiple leads in 19 cases. Among leads with an implant time of 〉12 months （n=19） mean implant duration （MID） was （46.4±15.2） （12-76） months. Groups were formed depending on infectious or non-infectious indications （INF vs. Non-INF）, and the use or non-use of extraction tools （ET1 vs. ET0）. Results Among patients with an implant duration of 〉12 months, complete procedural success was 94.7% and clinical success 100%. Operative mortality was zero. In the INF versus NON-INF groups complete procedural success （100% vs. 91.7%, P=0.43）, mean number of required extraction tools （0.7 （0-2） vs. 0.9 （0-3）, P=0.65） and MID （49.1±15.0 vs. 44.7±15.8, P=0.83） did not differ significantly. Comparing the groups ET1 and ET0 showed no significant differences in complications （n=l vs. n=l, P=-0.81） and MID （47.0±17.5 vs. 45.5±12.6, P=0.71）. Conclusions In specialized centers transvenous lead extraction of coronary sinus leads with a mean implant duration of almost four years can be performed safely and effectively. Neither non-infectious indications nor the use of extraction tools negatively affected the outcome of the procedure.
