脑动脉瘤血管内治疗的新技术

本文由美国加州大学尔湾分校医学院医学中心神经外科LI-MEI LIN教授团队执笔,详细总结并分析了近年来脑动脉瘤血管内治疗的重要进展.

Bifunctional LiI additive for poly(ethylene oxide)electrolyte with high ionic conductivity and stable interfacial chemistry

The development of polymer-based solid-state batteries is severely limited by the low ionic conductivity of solid polymer electrolyte and the instable interface between polymer electrolyte and Li-metal anode.In this work,lithium iodide(LiI)as a bifunctional additive was introduced into the poly(ethylene oxide)(PEO)-based electrolyte to improve the ionic conductivity and to construct a stable interphase at the Li/PEO interface.I-anions offer a strong electrostatic interaction with hydrogen atoms on PEO chains(HPEO)and forming massive I–H bonds that cross-link PEO chains,decrease crystallinity of PEO,and thus improve Li~+interchain transport.In addition,LiI participates in the formation of an inorganic-rich interphase layer,which decreases the energy barrier of Li+transport across the interface and thus inhibits the growth of lithium dendrites.As a result,the composite PEO electrolyte with 2 wt%LiI(PEO-2 LiI)presents a very high ionic conductivity of 2.1×10^(-4) S cm-1 and a critical current density of 2.0 m A cm^(-2) at 45°C.Li symmetric cell with this PEO-2 LiI electrolyte exhibits a long-term cyclability over 600 h at 0.2 m A cm^(-2).Furthermore,solid-state LiFePO_(4) and LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2) batteries with the PEO-2 LiI electrolyte show an impressive electrochemical performance with outstanding cycling stability and rate capability at 45°C.

Efficient conversion of CO_(2) into cyclic carbonates under atmospheric by halogen and metal-free poly(ionic liquid)s

A novel series of halogen free, hydroxyl group containing poly(ionic liquid)s(PILs) was first synthesized from glycerol dimethyl acrylate(GDA) and 1-vinyl imidazole(1-VIM) through free radical polymerization, follow by an alkylation step and an ion-exchange procedure to form the final imidazolium hydrogen carbonate heterogenous catalyst poly(HCO_(3)-OH-n). The chemical and physical properties were investigated by varying the monomer ratio between GDA and 1-VIM. Among them, poly(HCO_(3)-OH-2) exhibited the highest catalytic activity for CO_(2)cycloaddition, with the yield of chloropropene carbonate 90% under mild conditions(80℃, 0.1 MPa, 12 h, 0.15 g catalyst for 32 mmol epichlorohydrin) in the absence of any cocatalyst, metal or solvent. A range of substrates with good to excellent yields under atmosphere was obtained. The poly(HCO_(3)-OH-n) catalyst is collectable and still remains acceptable catalytic activity after six runs. Finally, a preliminary kinetic is calculated on the basis of poly(HCO_(3)-OH-2) with the activation energy value of 79.5 kJ·mol^(-1). This study highlights that the poly(HCO_(3)-OH-n) enable to reach efficient CO_(2) conversion under mild conditions.

A new long-side-chain sulfonated poly(2,6-dimethyl-1,4-phenylene oxide)(PPO)/polybenzimidazole(PBI)amphoteric membrane for vanadium redox flow battery

A new amphoteric membrane was prepared by blending long-side-chain sulfonated poly(2,6-dimethyl-1,4-phenylene oxide)(S-L-PPO)and polybenzimidazole(PBI)for vanadium redox flow battery(VRFB)application.An acid-base pair structure formed between the imidazole of PBI and sulfonic acid of S-L-PPO resulted in lowered swelling ratio.It favors to reduce the vanadium permeation.While,the increased sulfonic acid concentration ensured that proton conductivity was still at a high level.As a result,a better balance between the vanadium ion permeation(6.1×10^-9 cm^2·s^-1)and proton conductivity(50.8 m S·cm^-1)in the S-L-PPO/PBI-10%membrane was achieved.The VRFB performance with S-L-PPO/PBI-10%membrane exhibited an EE of 82.7%,which was higher than those of pristine S-L-PPO(81.8%)and Nafion 212(78.0%)at 120 m A·cm^-2.In addition,the S-LPPO/PBI-10%membrane had a much longer self-discharge duration time(142 h)than that of Nafion 212(23 h).

Micro-interface enhanced mass transfer sodium carbonate absorption carbon dioxide reaction

Micro-interface intensified reactor(MIR)can be applied in series/parallel in the absorption of CO_(2)in industrial gases by Na_(2)CO_(3)due to the ability to produce large numbers of stable microbubbles.This work focuses on the variation pattern of mass transfer characteristics parameters of the reaction gas in Na_(2)CO_(3) solution under the influence of different solution properties and operating parameters in the reaction of CO_(2)absorption by Na2CO3.The mass transfer characteristics parameters include bubble Sauter mean diameter,gas holdup,interfacial area,liquid side mass transfer coefficient,and liquid side volume mass transfer coefficient kLa.The solution properties and operating parameters include Na2CO3 concentration(0.05–2.0 mol·L^(-1)),superficial gas velocity(0.00221–0.01989 m·s^(-1)),superficial liquid velocity(0.00332–0.02984 m·s^(-1)),and ionic strength(1.42456–1.59588 mol·kg^(-1)).And volumetric mass transfer coeffi-cients kLa and superficial reaction rates r of the MIR and the bubble column reactor are compared in the reaction of sodium carbonate absorption of carbon dioxide,and the former shows a greater improvement under different solution properties and operating parameters.The enhanced role of MIR in mass transfer in non-homogeneous reactions is verified and the feasibility of industrial practical applications of MIR is demonstrated.

A simple hydroxypyridine ionic liquids for conversion of CO_(2)into quinazoline-2,4(1H,3H)-diones under atmospheric conditions

The transformation of CO_(2)into high value-added product is a promising pathway for utilizing CO_(2).However,the process tends to require harsh reaction conditions owing to CO_(2)chemical inertness.Designing a high efficiency catalytic system with environmentally benign characteristic are important determinants.In this work,protic ionic liquids[TMG][2-OPy]were prepared via one-step neutralization between 1,1,3,3-tetramethylguanidine and 2-hydroxypyridine,applying to the domain of synthesizing quinzoline-2,4(1 H,3H)-diones from CO_(2)and 2-aminobenzontiles without any solvent or metal,achieving the yield of 97%at 90℃for 8 h under atmospheric.A series of substrates with good to acceptable yield were detected,revealing the generality and universality of the catalyst.Furthermore,the system could be facilely reused for at least six runs,retaining the yield of 94%.A preliminary kinetic equation is calculated with the activation energy of 68 kJ·mol^(-1),and a plausible reaction mechanism was put forward.This study highlights that the[TMG][2-OPy]enables to activate CO_(2)carboxylation efficiently.

Electronegativity-Induced Single-Ion Conducting Polymer Electrolyte for Solid-State Lithium Batteries

The application of solid polymer electrolytes(SPEs)is severely impeded by the insufficient ionic conductivity and low Li^(+)transference numbers(t_(Li)^(+)).Here,we report an iodine-driven strategy to address both the two longstanding issues of SPEs simultaneously.Electronegative lodine-containing groups introduced on polymer chains effectively attract Li^(+)ions,facilitate Li^(+)transport,and promote the dissociation of Li salts.Meanwhile,iodine is also favorable to alleviate the strong O-Li^(+)coordination through a Lewis acidbase interaction,further improving the ionic conductivity and t_(Li)^(+).As a proof of concept,an iodinated single-ion conducting polymer electrolyte(IPE)demonstrates a high ionic conductivity of 0.93 mS cm^(-1)and a high t_(Li)^(+)of 0.86 at 25℃,which is among the best results ever reported for SPEs.Moreover,symmetric Li/Li cells with IPE achieve a long-term stability over 2600 h through the in-situ formed LiF-rich interphase.As a result,Li-S battery with IPE maintains a high capacity of 623.7 mAh g^(-1)over 300 cycles with an average Coulombic efficiency of 99%.When matched with intercalation cathode chemistries,Li/IPE/LiFePO_(4)and Li/IPE/LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)solid-state batteries also deliver high-capacity retentions of 95%and 97%at 0.2 C after 120 cycles,respectively.

Determination of the Content of Kaempferol from Fermented Ginkgo( Ginkgo biloba L.) Leaves

[Objectives] This study was conducted to determine kaempferol content in ginkgo( Ginkgo biloba L.) leaves subjected to microbial fermentation.[Methods]Bacillus licheniformis was selected for solid-state fermentation of ginkgo leaves,and the content of kaempferol in ginkgo leaves was determined by RPHPLC method. At first,methanol was used to extract flavonoid glycosides,which were then hydrolyzed by hydrochloric acid solution. HPLC was performed with Platisil ODS column C18( 150 mm ×4. 6 mm,5 μm) using mobile phase Vmethanol∶ Vwater( 0. 4% phosphoric acid solution) = 55∶45 at a flow rate of 1 ml/min,and the eluate was detected with a shimadzu HPLC ultraviolet detector at 360 nm. [Results]With kaempferol as the reference substance,the correlation coefficient was0. 999 2 in the range of 0. 001 06-0. 016 96 g/L. The content in the fermented product was less than that in the non-fermented product by 28%. [Conclusions]The method is simple,accurate,and is suitable for determination of kaempferol. This study will provide an experimental basis for the development and utilization of ginkgo.

Analysis of the Probability Model of Wind Load on the Offshore Wind Turbine

According to the actual measurement data, probability models of horizontal wind load were obtained based on wind velocity statistic and power spectral density function of fluctuating wind velocity through stochastic sampling and using spectrum analysis method. Through the comparison of two models, probability models of horizontal wind load based on probability models of fluctuating wind velocity were obtained by revising the mean and variance of fluctuating wind velocity. Results show that the variance takes lower value when the power spectral density function of fluctuating wind velocity is used to obtain the probability model of horizontal wind load. The quadratic term of fluctuating wind velocity takes a small contribution value in total wind load with almost no contribution to the model of horizontal wind load. It is convenient for practical engineering to obtain the models of horizontal wind load by using probability models of fluctuating wind velocity.

Application Study on Rigidity Correlation Method for Density Inversion of Rockfill

Based on the theoretical model of rigidity correlation method, the study on application was carried out with Chinese Liyuan face rockfill dam as example. The linear relation equations between the rockfill rigidity and density measured by pit method were established, and the regression performance and accuracy of rigidity correlation method were analyzed by calculating the inversion values of density. The results show that the regression equations of rigidity correlation method are high significant so as to work out the rockfill density precisely;rigidity correlation method is used for density inversion of rockfill with minor error and namely high accuracy, which is proper with satisfactory results.

基于准二维钙钛矿的高稳定电阻随机存储器

电阻式随机存储器(RRAM)一直被视为新兴存储器技术中具有挑战性的替代品.近年来,人们发现基于有机-无机杂化卤化物钙钛矿的RRAM具有优异的存储特性.本研究利用简单的一步旋涂策略,在空气中不使用反溶剂,制备出了具有准二维钙钛矿活性层的Al/(PEA)_(2)-MAPb_(2)I_(3)Br_(4)/SnO_(2)/氧化铟锡(ITO)非易失性RRAM,该器件表现出了出色且高度稳定的双极性电阻切换特性.此外,该器件表现出约为10~4的开/关比,低SET电压(约0.8 V),并且具有相对稳定的耐久性(大于1000次循环).高阻态和低阻态的传导机制分别是空间电荷限流传导和欧姆传导.此外,由于苯乙胺分子的疏水性,该器件在40%湿度下放置90天依然表现出显著的阻变特性.因此,这种高性能、稳定的RRAM为未来存储器的商业化提供了可能性.

Attitude-adjusting dynamical behavior of cubic rover on low-gravity testbed

Cubic rovers that traverse by hopping systems are promising in low-gravity environments.Although several analyses of the control methods and mobility of the cubic rover are available,investigations of its attitude-adjusting behavior are still limited.This study derives the dynamic equations of the two attitude-adjusting modes of the cubic rover,referred to as walking and twisting.The relationships between the speed threshold and rotation angle of the cubic rover were investigated in both rigid and regolith environments using a self-designed low-gravity testbed.Comparative studies were conducted by considering the experimental and simulated outputs.The results of this study can be interesting for roving mission planning when exploring planetary moons and small celestial bodies.

New spinal robotic technologies

Robotic systems in surgery have developed rapidly. Installations of the da Vinci Surgical System® (Intuitive Surgical, Sunnyvale, CA,, USA), widely used in urological and gynecological procedures, have nearly doubled in the United States from 2010 to 2017. Robotics systems in spine surgery have been adopted more slowly;however, users are enthusiastic about their applications in this subspecialty. Spinal surgery often requires fine manipulation of vital structures that must be accessed via limited surgical corridors and can require repetitive tasks over lengthy periods of time — issues for which robotic assistance is well-positioned to complement human ability. To date, the United States Food and Drug Administration (FDA) has approved 7 robotic systems across 4 companies for use in spinal surgery. The available clinical data evaluating their efficacy have generally demonstrated these systems to be accurate and safe. A critical next step in the broader adoption of surgical robotics in spine surgery is the design and implementation of rigorous comparative studies to interrogate the utility of robotic assistance. Here we discuss current applications of robotics in spine surgery, review robotic systems FDA-approved for use in spine surgery, summarize randomized controlled trials involving robotics in spine surgery, and comment on prospects of robotic-assisted spine surgery.

The Genomes of the Allohexaploid Echinochloa crus-galli and Its Progenitors Provide Insights into Polyploidization-Driven Adaptation

The hexaploid species Echinochloa crus-galli is one of the most detrimental weeds in crop fields,especially in rice paddies.Its evolutionary history is similar to that of bread wheat,arising through polyploidization after hybridization between a tetraploid and a diploid species.In this study,we generated and analyzed high-quality genome sequences of diploid(E.haploclada),tetraploid(E.oryzicola),and hexaploid(E.crus-galli)Echinochloa species.Gene family analysis showed a significant loss of disease-resistance genes such as those encoding NB-ARC domain-containing proteins during Echinochloa polyploidization,contrary to their significant expansionduring wheat polyploidization,suggesting that natural selection might favor reduced investment in resistance in this weed to maximize its growth and reproduction.In contrast to the asymmetric patterns of genome evolution observed in wheat and other crops,no significant differences in selection pressure were detected between the subgenomes in E.oryzicola and E.crus-galli.In addition,distinctive differences in subgenome transcriptome dynamics during hexaploidization were observed between E.crus-galli and bread wheat.Collectively,our study documents genomic mechanisms underlying the adaptation of a major agricultural weed during polyploidization.The genomic and transcriptomic resources of three Echinochloa species and new insights into the polyploidization-driven adaptive evolution would be useful for future breeding cereal crops.

Cerebral aneurysm treatment: modern neurovascular techniques

Endovascular treatment of cerebral aneurysm continues to evolve with the development of new technologies.This review provides an overview of the recent major innovations in the neurointerventional space in recent years.

Horizontal transfer and evolution of the biosynthetic gene cluster for benzoxazinoids in plants

Benzoxazinoids are a class of protective and allelopathic plant secondary metabolites that have been identified in multiple grass species and are encoded by the Bx biosynthetic gene cluster(BGC)in maize.Data mining of 41 high-quality grass genomes identified complete Bx clusters(containing genes Bx1–Bx5 and Bx8)in three genera(Zea,Echinochloa,and Dichanthelium)of Panicoideae and partial clusters in Triticeae.The Bx cluster probably originated from gene duplication and chromosomal translocation of native homologs of Bx genes.An ancient Bx cluster that included additional Bx genes(e.g.,Bx6)is presumed to have been present in ancestral Panicoideae.The ancient Bx cluster was putatively gained by the Triticeae ancestor via horizontal transfer(HT)from the ancestral Panicoideae and later separated into multiple segments on different chromosomes.Bx6 appears to have been under less constrained selection compared with the Bx cluster during the evolution of Panicoideae,as evidenced by the fact that it was translocated away from the Bx cluster in Zea mays,moved to other chromosomes in Echinochloa,and even lost in Dichanthelium.Further investigations indicate that purifying selection and polyploidization have shaped the evolutionary trajectory of Bx clusters in the grass family.This study provides the first candidate case of HT of a BGC between plants and sheds new light on the evolution of BGCs.

Self-assembled nanoformulations of paclitaxel for enhanced cancer theranostics

Chemotherapy has occupied the critical position in cancer therapy,especially towards the post-operative,advanced,recurrent,and metastatic tumors.Paclitaxel(PTX)-based formulations have been widely used in clinical practice,while the therapeutic effect is far from satisfied due to off-target toxicity and drug resistance.The caseless multi-components make the preparation technology complicated and aggravate the concerns with the excipients-associated toxicity.The self-assembled PTX nanoparticles possess a high drug content and could incorporate various functional molecules for enhancing the therapeutic index.In this work,we summarize the self-assembly strategy for diverse nanodrugs of PTX.Then,the advancement of nanodrugs for tumor therapy,especially emphasis on monochemotherapy,combinational therapy,and theranostics,have been outlined.Finally,the challenges and potential improvements have been briefly spotlighted.

Pedicle screw accuracy assessment in ExcelsiusGPS?robotic spine surgery:evaluation of deviation from pre-planned trajectory

Background: The ExcelsiusGPS?(Globus Medical, Inc., Audubon, PA) is a next-generation spine surgery robotic system recently approved for use in the United States. The objective of the current study is to assess pedicle screw accuracy and clinical outcomes among two of the first operative cases utilizing the ExcelsiusGPS?robotic system and describe a novel metric to quantify screw deviation. Methods: Two patients who underwent lumbar fusion at a single institution with the ExcelsiusGPS?surgical robot were included. Pre-operative trajectory planning was performed from an intra-operative CT scan using the O-arm (Medtronic, Inc., Minneapolis, MN). After robotic-assisted screw implantation, a post-operative CT scan was obtained to confirm ideal screw placement and accuracy with the planned trajectory. A novel pedicle screw accuracy algorithm was devised to measure screw tip/tail deviation distance and angular offset on axial and sagittal planes. Screw accuracy was concurrently determined by a blinded neuroradiologist using the traditional Gertzbein-Robbins method. Clinical variables such as symptomatology, operative data, and post-operative follow-up were also collected. Results: Eight pedicle screws were placed in two L4-L5 fusion cases. Mean screw tip deviation was 2.1 mm (range 0.8-5.2 mm), mean tail deviation was 3.2 mm (range 0.9-5.4 mm), and mean angular offset was 2.4 degrees (range 0.7-3.8 degrees). All eight screws were accurately placed based on the Gertzbein-Robbins scale (88% Grade A and 12% Grade B). There were no cases of screw revision or new post-operative deficit. Both patients experienced improvement in Frankel grade and Karnofsky Performance Status (KPS) score by 6 weeks post-op. Conclusion: The ExcelsiusGPS? robot allows for precise execution of an intended pre-planned trajectory and accurate screw placement in the first patients to undergo robotic-assisted fusion with this technology.

Procedural complexity independent of P2Y12 reaction unit(PRU)values is associated with acute in situ thrombosis in Pipeline flow diversion of cerebral aneurysms

background Acute in situ thrombosis is an ischaemic phenomenon during Pipeline embolisation device(PED)procedures with potentially high morbidity and mortality.There is controversy regarding the role of platelet function testing with P2Y12 assay as a predictor of intraprocedural thromboembolic events.There is limited knowledge on whether procedural complexity influences these events.Methods Data were collected retrospectively on 742 consecutive PED cases at a single institution.Patients with intraprocedural acute thrombosis were compared with patients without these events.results A cohort of 37 PED cases with acute in situ thrombosis(mean age 53.8 years,mean aneurysm size 8.4 mm)was matched with a cohort of 705 PED cases without intraprocedural thromboembolic events(mean age 56.4 years,mean aneurysm size 6.9 mm).All patients with in situ thrombosis received intra-arterial and/or intravenous abciximab.The two groups were evenly matched in patient demographics,previous treatment/subarachnoid hemorrhage(SAH)and aneurysm location.There was no statistical difference in postprocedural P2Y12 reaction unit(PRU)values between the two groups,with a mean of 156 in the in situ thrombosis group vs 148 in the control group(p=0.5894).Presence of cervical carotid tortuosity,high cavernous internal carotid artery grade,need for multiple PED and vasospasm were not significantly different between the two groups.The in situ thrombosis group had statistically significant longer fluoroscopy time(60.4 vs 38.4 min,p<0.0001),higher radiation exposure(3476 vs 2160 mGy,p<0.0001),higher rates of adjunctive coiling(24.3% vs 8.37%,p=0.0010)and higher utilisation of balloon angioplasty(37.8% vs 12.2%,p<0.0001).Clinically,the in situ thrombosis cohort had higher incidence of major and minor stroke,intracerebral haemorrhage and length of stay.Conclusions Predictors of procedural complexity(higher radiation exposure,longer fluoroscopy time,adjunctive coiling and need for balloon angioplasty)are associated with acute thrombotic events during PED placement,independent of PRU values.

Construction of an Infectious Clone for Mosquito-Derived Tembusu Virus Prototypical Strain

Dear Editor,Duck Tembusu virus(DTMUV),a member of the Flavivirus genus within the Flaviviridae family,has caused huge economic losses to the poultry industry in China and even in Asia since 2010(Zhang et al.2017).The first strain of Tembusu virus(TMUV)MM_1775 was isolated from mosquitoes in 1955 in Malaysia(Platt et al.1975).DTMUV CQW1 strain(GenBank:KM233707.1)was isolated from the liver tissue of Cherry Valley ducks in southwest China in 2015(Zhu et al.2015).The positive control rCQW1 was rescued from an infectious clone that contained the full-length cDNA of CQW1.And the complete cDNA was positioned under the control of the T7 promoter elements for in vitro transcription(Chen et al.2018).The relationship between TMUV evolution and pathogenic variants has not been revealed.The fundamental reason is the lack of the in vitro operation platform for the prototypical strain genome.