BL03HB: a Laue microdiffraction beamline for both protein crystallography and materials science at SSRF

A Laue microdiffraction beamline(BL03HB) was constructed at the Shanghai Synchrotron Radiation Facility(SSRF).This beamline features two consecutive focusing points in two different sectors within its end station, the first dedicated to protein crystallography and the other tailored to materials science applications. Based on a superbend dipole magnet with a magnetic field of 2.29 T, a two-stage focusing design was implemented with two sets of Kirkpatrick-Baez mirrors to achieve a micro white beam as small as 4.2 μ m ×4.3 μ m at the first sector and 0.9 μ m ×1.3 μ m at the second sector in the standard beamline operation mode at SSRF. The X-ray microbeam in the two sectors can be easily switched between monochromatic and white beams by moving a four-bounce monochromator in or out of the light path, respectively. In the protein crystallography sector, white-beam Laue microdiffraction was demonstrated to successfully determine the structure of protein crystals from only a few images of diffraction data collected by a Pilatus 2 M area detector. In the materials science sector,the white-beam Laue diffraction was collected in a reflection geometry using another Pilatus 2 M area detector, which could map the microstructural distribution on the sample surface by scanning the samples. In general, the BL03HB beamline promotes the application of Laue microdiffraction in both protein crystallography and materials science. This paper presents a comprehensive overview of the BL03HB beamline, end station, and the first commission results.

胃扭转

胃扭转是一种少见病,发病高峰年龄为40~60岁和小于1岁人群,多与膈肌异常和胃韧带缺陷相关,临床分为急性和慢性胃扭转,急性胃扭转可危及生命,根据Borchardt三联征症状和X线钡餐检查可做出诊断,本文对胃扭转的病因、分类、诊断及治疗研究进展进行综述,以期提高对胃扭转的诊治水平。

视神经脊髓炎相关性视神经炎实验模型的建立及应用

视神经脊髓炎(NMO)为亚裔人群高发、神经眼科交叉、体液免疫主导的炎症性中枢神经系统星形胶质细胞病,因其高致病性、高复发风险和预后差而备受关注。NMO相关性视神经炎(NMO-ON)患者很难从常规治疗中获益,多遗留不同程度的视神经萎缩。NMO-ON研究的一个局限是实验模型的不足,故本文就NMO及NMO-ON实验模型的研究进展及应用作一综述,旨在探究NMO视功能损害的病理学机制及可能的治疗方法。

Transcatheter arterial chemoembolization followed by immediate radiofrequency ablation for large solitary hepatocellular carcinomas

AIM: To assess the technical safety and efficacy of transcatheter arterial chemoembolization (TACE) combined with immediate radiofrequency ablation (RFA) for large hepatocellular carcinomas (HCC) (maximum diameter ≥ 5 cm). METHODS: Individual lesions in 18 patients with HCCs (mean maximum diameter: 7.5 cm; range: 5.1-15.5 cm) were treated by TACE combined with percutaneous RFA between January 2010 and June 2012. All of the patients had previously undergone one to four cycles of TACE treatment. Regular imaging and laboratory tests were performed to evaluate the rate of technical success, technique-related complications, local-regional tumor responses, recurrence-free survival time and survival rate after treatment.RESULTS: Technical success was achieved for all 18 visible HCCs. Complete response (CR) was observed in 17 cases, and partial response was observed in 1 case 1 mo after intervention. The CR rate was 94.4%. Local tumors were mainly characterized by coagulative necrosis. During follow-up (2-29 mo), the mean recurrencefree survival time was 16.8 ± 4.0 mo in 17 cases of CR. The estimated overall survival rate at 6, 12, and 18 mo was 100%. No major complications were observed. Levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the blood of 17 patients transiently increased on the third day after treatment (ALT 200.4 ± 63.4 U/L vs 24.7 ± 9.3 U/L, P < 0.05; AST 228.1 ± 25.4 U/L vs 32.7 ± 6.8 U/L, P < 0.05). Severe pain occurred in three patients, which was controlled with morphine and fentanyl. CONCLUSION: TACE combined with immediate RFA is a safe and effective treatment for large solitary HCCs. Severe pain is a major side effect, but can be controlled by morphine.

Effect of Zn addition on microstructure and mechanical properties of cast Mg-Gd-Y-Zr alloys

The effects of Zn addition on the microstructure and mechanical properties of Mg.10Gd.3Y.0.6Zr(wt.%)alloys in the as-cast,solution-treated,and peak-aged conditions were investigated.Experimental results reveal that the microstructure of the as-cast alloy without Zn consists ofα-Mg and Mg24(Gd,Y)5 phases,and the alloy with 0.5 wt.%Zn consists ofα-Mg,(Mg,Zn)3(Gd,Y)and Mg24(Gd,Y,Zn)5 phases.With the addition of Zn increasing to 1 wt.%,the Mg24(Gd,Y,Zn)5 phase disappears and some needle-like stacking faults distribute along the grain boundaries.Moreover,the 18R long-period stacking ordered(LPSO)phase is observed in the as-cast alloy with 2 wt.%Zn.After solution treatment,the Mg24(Gd,Y)5 and Mg24(Gd,Y,Zn)5 eutectic phases are completely dissolved,and the(Mg,Zn)3(Gd,Y)phase,needle-like stacking faults and 18R LPSO phase all transform into 14H LPSO phase.Both the suitable volume fraction of 14H LPSO phases and the fine ellipsoidal-shapedβ′phases make the peak-aged alloy with 0.5 wt.%Zn exhibit excellent comprehensive mechanical properties and the UTS,YS and elongation are 338 MPa,201 MPa and 6.8%,respectively.

The protein complex crystallography beamline(BL19U1)at the Shanghai Synchrotron Radiation Facility

The protein complex crystallographic beamline BL19U1 at the Shanghai Synchrotron Radiation Facility is one of the five beamlines dedicated to protein sciences operated by National Facility for Protein Science(Shanghai,China).The beamline,which features a small-gap invacuum undulator,has been officially open to users since March 2015.This beamline delivers X-ray in the energy range 7–15 keV.With its high flux,low divergence beam and a large active area detector,BL19U1 is designed for proteins with large molecular weight and large crystallographic unit cell dimensions.Good performance and stable operation of the beamline have allowed the number of Protein Data Bank(PDB)depositions and the number of articles published based on data collected at this beamline to increase steadily.To date,over 300 research groups have collected data at the beamline.More than 600 PDB entries have been deposited at the PDB(www.pdb.org).More than 300 papers have been published that include data collected at the beamline,including 21 research articles published in the top-level journals Cell,Nature,and Science.

Upgrade of macromolecular crystallography beamline BL17U1at SSRF

Beamline BL17 U1 at Shanghai Synchrotron Radiation Facility is an energy-tunable macromolecular crystallography beamline that has been in user operation since 2009. Growing demand from the user community for a small beam and related experimental methods have motivated upgrades of the devices in the endstation.Minibeam modes have already been developed for operation. A self-integrated diffractometer reduces the sphere of confusion of the rotatory axis to 1μm. The new diffractometer is equipped with an upgraded on-axis viewing system that can improve the resolving power. Additionally,the area detector was also upgraded to the newest generation of detectors, the EIGER X 16 M, which can collect data at 133 Hz. After these upgrades, the endstation became virtually new. This paper covers the upgrade of the endstation devices and gives the first data collection results.

Embryonic liver fordin is involved in glucose glycolysis of hepatic stellate cell by regulating PI3K/Akt signaling

AIM To investigate the role of embryonic liver fordin(ELF) in liver fibrosis by regulating hepatic stellate cells(HSCs) glucose glycolysis.METHODS The expression of ELF and the glucose glycolysisrelated proteins were evaluated in activated HSCs. si RNA was used to silence ELF expression in activated HSCs in vitro and the subsequent changes in PI3K/Akt signaling and glucose glycolysis-related proteins were observed.RESULTS The expression of ELF increased remarkably in HSCs of the fibrosis mouse model and HSCs that were cultured for 3 wk in vitro. Glucose glycolysis-related proteins showed an obvious increase in the activated HSCs, such as phosphofructokinase, platelet and glucose transporter 1. ELF-si RNA, which perfectly silenced the expression of ELF in activated HSCs, led to the induction of glucose glycolysis-related proteins and extracellular matrix(ECM) components. Moreover, p Akt, which is an important downstream factor in PI3K/Akt signaling, showed a significant change in response to the ELF silencing. The expression of glucose glycolysisrelated proteins and ECM components decreased remarkably when the PI3K/Akt signaling was blocked by Ly294002 in the activated HSCs. CONCLUSION ELF is involved in HSC glucose glycolysis by regulating PI3K/Akt signaling.

Beam dynamics,RF measurement,and commissioning of a CW heavy ion IH-DTL

A 53.667 MHz CW(continuous-wave) heavy ion IH-DTL has been designed for the SSC-LINAC injector of HIRFL-CSR(Heavy Ions Research Facility at Lanzhou-Cooling Storage Ring). It accelerates ions with maximum mass-to-charge ratio of 7.0 from 143 to 295 ke V/u. Low-power RF measurement of the IH-DTL1 has been taken to investigate the RF performance and the quality of the electric field distribution on the beam axis.The measured Q_0 value and the shunt impedance are 10,400 and 198 MX/m, respectively. The electric field distributions on and around the beam axis were evaluated and compared with the design value. By a new approach,the dipole field component is also estimated. The beam dynamics simulation using measured field distribution was presented in this paper. Based on the dynamics analysis in both transverse and longitudinal phase space, the field distribution can meet the design requirement. Finally, the RF conditioning and very first beam commissioning on the IH-DTL1 were finished. The beam test results agree well with the simulation results; what's more, the property of the variable output beam energy about the separated functions DTL was verified.

Efficacy of conbercept after switching from bevacizumab/ranibizumab in eyes of macular edema secondary to central retinal vein occlusion

AIM: To explore the efficacy of conbercept after switching from bevacizumab/ranibizumab in eyes of central retinal vein occlusion(CRVO) through optical coherence tomography angiography(OCTA). METHODS: Patients with prior treatment of a minimum of three consecutive intravitreal injections of either bevacizumab or ranibizumab, followed by injection of conbercept, were recruited. The minimal follow-up period after switching was 12 mo. Central retinal thickness(CRT), best-corrected visual acuity(BCVA), the interval of injections was reviewed. Perfusion density(PD) and vascular length density(VLD) of superficial and deep capillary plexus were acquired from OCTA images before and after switching. RESULTS: Twenty-four eyes were included. CRT significantly decreased from 460.71±153.23 μm(before switching) to 283.92±38.27 μm at the end of follow-up(P<0.001). However, BCVA gained to some extent(from 0.98±0.33 to 0.76±0.42 log MAR) but the difference was not significant(P=0.070). After switching to conbercept the injection interval extended from 5.2±2.3 wk to 8.3±3.9 wk(P=0.012). At the end of follow-up, PD of deep retinal layer decreased significantly compared with before switching(from 34.62%±5.27% to 33.26%±5.82%, P=0.016), similar result was found in VLD of deep retinal layer but not in PD or VLD in superficial layer.CONCLUSION: In cases of refractory macular edema secondary to CRVO, switching to conbercept improves macular thickness and extends interval of injection. Retinal microvasculature cannot improve with treatment of conbercept.

Fabrication and cold test of prototype of spatially periodic radio frequency quadrupole focusing linac

A 325 MHz aluminum prototype of a spatially periodic RF quadrupole focusing linac was developed at the Institute of Modern Physics,Chinese Academy of Sciences,as a promising candidate for the front end of a high-current linac.It consists of an alternating series of crossbar H-type drift tubes and RF quadrupole sections.Owing to its special geometry,cavity fabrication is a major hurdle for its engineering development and application.In this paper,we report the detailed mechanical design of this structure and describe its fabrication process,including machining,assembly,and inspection.The field distribution was measured by the bead-pull technique.The results show that the field errors of both the accelerating and focusing fields are within an acceptable range.A tuning scheme for this new structure is proposed and verified.The cold test process and results are presented in detail.The development of this prototype provides valuable guidance for the application of the spatially periodic RF quadrupole structure.

Realization of low-energy type-Ⅱ Dirac fermions in(Ir_(1-x)Pt_x)Te_2 superconductors

Topological Dirac semimetals(DSMs) present a kind of topologically nontrivial quantum state of matter, which has massless Dirac fermions in the bulk and topologically protected states on certain surfaces. In superconducting DSMs, the effects of their nontrivial topology on superconducting pairing could realize topological superconductivity in the bulk or on the surface. As superconducting pairing takes place at the Fermi level E_F, to make the effects possible, the Dirac points should lie in the vicinity of E_F so that the topological electronic states can participate in the superconducting paring. Here,we show using angle-resolved photoelectron spectroscopy that in a series of(Ir_(1-x)Pt_x)Te_2 compounds, the type-Ⅱ Dirac points reside around E_F in the superconducting region, in which the bulk superconductivity has a maximum T_c of ～ 3 K.The realization of the coexistence of bulk superconductivity and low-energy Dirac fermions in(Ir_(1-x)Pt_x)Te_2 paves the way for studying the effects of the nontrivial topology in DSMs on the superconducting state.

Morphological and structural damage investigation of nanostructured molybdenum fuzzy surface after pulsed plasma bombardment

Steady high-flux helium(He)plasma with energy ranging from 50 eV to 90 eV is used to fabricate a fiber-form nanostructure called fuzz on a polycrystalline molybdenum(Mo)surface.Enhanced hydrogen(H)pulsed plasma in a wide power density range of 12 MW/m^(2)-35 MW/m^(2)is subsequently used to bombard the fuzzy Mo,thereby simulating the damage of edge localized mode(ELM)to fuzz.The comparisons of surface morphologies,crystalline structures,and optical reflectivity between the original Mo and the Mo treated with various He^(+)energy and transient power densities are performed.With the increase of He ion energy,the Mo nano-fuzz evolved density is enlarged due to the decrease of filament diameter and optical reflectivity.The fuzz-enhanced He release should be the consequence of crystalline growth and the lattice shrinkage inside the Mo-irradiated layers(^(2)00 nm).The fuzz induced by lower energy experiences more severe melting damage and dust release under the condition of the identical transient H plasma-bombardment.The H and He are less likely to be trapped due to aggravated melting evidenced by the enhanced crystalline size and distinct lattice shrinkage.As the transient power density rises,the thermal effect is enhanced,thereby causing the fuzz melting loss to aggravate and finally to completely disappear when the power density exceeds 21 MW/m^(2).Irreversible grain expansion results in huge tensile stress,leading to the observable brittle cracking.The effects of transient thermal load and He ion energy play a crucial role in etching Mo fuzz during ELM transient events.

Continuous droplet rebound on heated surfaces and its effects on heat transfer property: A lattice Boltzmann study

A thermal multiphase lattice Boltzmann(LB) model is used to study the behavior of droplet impact on hot surface and the relevant heat transfer properties.After validating the correctness of the codes through the D^(2) law,the simulations of intrinsic contact angle and the temperature-dependent surface tension are performed.The LB model is then used to simulate the droplet impact on smooth and micro-hole heated surface.On the smooth surface,the impinging droplet is reluctant to rebound,unless the intrinsic wettability of the solid surface is fairly good.On the micro-hole surface,however,the micro-holes provide favorable sites for generating a high-pressure vapor cushion underneath the impinging droplet,which thereby facilitates the continuous droplet rebound.For the continuously rebounding droplet.The time evolution of volume and temperature display obvious oscillations.The achievable height of the rebounding droplet increases as the intrinsic wettability of the solid surface becomes better,and the maximum transient heat flux is found to be directly proportional to the droplet rebounding height.Within a certain time interval,the continuous rebounding behavior of the droplet is favorable for enhancing the total heat quantity/heat transfer efficiency,and the influence of intrinsic wettability on the total heat during droplet impingement is greater than that of the superheat.The LB simulations not only present different states of droplets on hot surfaces,but also guide the design of the micro-hole surface with desirable heat transfer properties.

Effects of heat transfer in a growing particle layer on microstructural evolution during solidification of colloidal suspensions

Heat transfer is the foundation of freezing colloidal suspensions and a key factor for the interface movement.However,how the thermal conductivity of particles affects freezing microstructural evolution remains unknown.Here in this work,a mathematical model is built up to investigate thermal interactions among a growing particle layer,pulling speeds,and the freezing interface under a thermal gradient.Experiments are conducted to confirm the tendency predictions of the model.With the increase of pulling speeds,the drifting distance of the freezing interface increases and the time to finish drifting decreases.When the thermal conductivity of particles(k_(p))is smaller than that of the surrounding(kw),the freezing interface tends to go forward to the warm side.Contrarily,the freezing interface tends to go back to the cold side when the thermal conductivity of particles is larger than that of the surrounding(α=k_(p)/k_(w)>1).It originates from the shape of the local freezing interface:convex(α<1)or concave(α>1).These morphological changes in the local interface modify the premelting drag force F_(f).Whenα<1,F_(f)decreases and the freezing morphology tends to be the frozen fringe.Whenα>1,F_(f)increases and the freezing morphologies tend to be ice spears.These understandings of how the thermal conductivity of particles affect microstructural evolution may optimize the production of freeze-casting materials and their structural-functional properties.

Effect of interface anisotropy on tilted growth of eutectics:A phase field study

Interfacial energy anisotropy plays an important role in tilted growth of eutectics. However, previous studies mainly focused on the solid-solid interface energy anisotropy, and whether the solid-liquid interface energy anisotropy can significantly affect the tilted growth of eutectics still remains unclear. In this study, a multi-phase field model is employed to investigate both the effect of solid-liquid interfacial energy anisotropy and the effect of solid-solid interfacial energy anisotropy on tilted growth of eutectics. The findings reveal that both the solid-liquid interfacial energy anisotropy and the solid-solid interfacial energy anisotropy can induce the tilted growth of eutectics. The results also demonstrate that when the rotation angle is within a range of 30°-60°, the growth of tilted eutectics is governed jointly by the solid-solid interfacial energy anisotropy and the solid-liquid interfacial energy anisotropy;otherwise, it is mainly controlled by the solid-solid interfacial energy anisotropy. Further analysis shows that the unequal pinning angle at triple point caused by the adjustment of the force balance results in different solute-diffusion rates on both sides of triple point. This will further induce an asymmetrical concentration distribution along the pulling direction near the solid-liquid interface and the tilted growth of eutectics. Our findings not only shed light on the formation mechanism of tilted eutectics but also provide theoretical guidance for controlling the microstructure evolution during eutectic solidification.

GA-SVC model and application of comprehensive evaluation of coal mine essential safety management

In order to evaluate the level of the coal mine essential safety management, the comprehensive index system was designed base on the connotation principle of the mine essential safety management. Due to the disadvantage of index weight setting by subjective idea in the former method, support vector classification algorithm was used to assess the level of coal mine essential safety management. According to the advantages of the global search capability of the genetic algorithm, support vector classification parameters optimization method was proposed based on genetic algorithm, and genetic algorithm-support vector classification model of coal mine essential safety management assessment was established. Learning samples were constructed on the basis of former data of mine essential safety management evaluation. The test results show that the genetic algorithm-support vector classification model has higher evaluation accuracy and good generalization ability, and the advantage of no need for artificial setting of index weight and absence of the subjective factors influence to evaluation results.

Mechanism of panax notoginseng in treating vitreous hemorrhage based on network pharmacology

Objective:To investigate the possible molecular mechanism of panax notoginseng in the treatment of vitreous hemorrhage(VH).Methods:The active components of Panax notoginseng were screened by TCMSP database and the corresponding targets were collected.Vh-related gene targets were derived from GeneCards and OMIM database,and the target of Panax notoginseng was mapped to disease target genes.STRING database and Cytoscape 3.7.2 software were used to construct the protein-protein interaction(PPI)network diagram and the interaction network of"Pantoginseng-active ingredient-VH-target protein",and the core action target genes were screened out.Finally,gene body(GO)biological process and metabolic pathway enrichment analysis of KEGG were performed on the potential therapeutic targets.Results:We identified 8 active components,162 active component targets,1387 VHrelated genes and 75 candidate targets for VH.In the"Panax notoginseng-active ingredient-VH-target protein"interaction network,there are 82 nodes in total.The core target genes include AKT1,CASP3,VEGF-A,IL-6 and MMP-9.143 major enrichment pathways were identified by GO and KEGG enrichment analysis.The key signal pathways include age-RAGE signaling pathway,fluid shear stress and atherosclerosis,etc.,and the significant molecular functions include cytokine activity,receptor ligand activity,cytokine receptor binding,etc.Conclusion:The potential molecular mechanism of panax notoquinone in the treatment of VH is closely related to the biological processes of anti-angiogenesis,anti-inflammation,regulation of apoptosis and oxidative stress,and AKT1,CASP3,VEGF-A,IL-6 and MMP-9 may be the core target genes.

Comparison of the closed analytical solution on the parameters of the alignment and surveying of the elements of accelerator under random errors

Purpose Compared with the iterative approximation solution,the analytically rigorous solution of the parameters of the accelerator alignment and surveying is the closed theoretical solution.To make the calculated error meet the negligible principle,in this paper,such examples of the zero,small angle and small translation,only large translation and no angle,only large angle without translation and large translation and large angle parameters under random errors are constructed.Methods Furthermore,Singular Value Decomposition,Eigen Value Decomposition,Polar Decomposition,Orthogonal Procrustes Analysis,and Successive Equivalent Differences Transformation are compared.Results In all the above examples,the mutual calculation deviation of Singular Value Decomposition,Eigen Value Decomposition,Polar Decomposition,and Orthogonal Procrustes analysis methods is less than 10 um.Its calculation accuracy is the highest,and Successive Equivalent Differences Transformation-3 has the largest calculation error,and Successive Equivalent Differences Transformation-N is in the middle.The results show that the coordinate residuals,parameters offsets and point position errors of the above solutions with random errors are all nearly zero.Conclusion It shows that the closed analytical solution is a rigorous solution.Moreover,it also shows that the constructed method of the coordinate point pairs is correct.

A comparison of perioperative outcomes between extraperitoneal robotic single-port and multiport radical prostatectomy with the da Vinci Si Surgical System

To evaluate outcomes between extraperitoneal robotic single-port radical prostatectomy(epR-spRP)and extraperitoneal robotic multiport radical prostatectomy(epR-mpRP)performed with the da Vinci Si Surgical System,comparison was performed between 30 single-port(SP group)and 26 multiport(MP group)cases.Comparisons included operative time,estimated blood loss(EBL),hospital stay,peritoneal violation,pain scores,scar satisfaction,continence,and erectile function.The median operation time and EBL were not different between the two groups.In the SP group,the median operation time of the first 10 patients was obviously longer than that of the latter 20 patients(P<0.001).The median postoperative hospital stay in the SP group was shorter than that in the MP group(P<0.001).The rate of peritoneal damage in the SP group was less than that in the MP group(P=0.017).The pain score and overall need for pain medications in the SP group were lower than those in the MP group(P<0.001 and P=0.015,respectively).Patients in the SP group were more satisfied with their scars than those in the MP group 3 months postoperatively(P=0.007).At 3 months,the cancer control,recovery of erectile function,and urinary continence rates were similar between the two groups.It is safe and feasible to perform epR-spRP using the da Vinci Si surgical system.Therefore,epR-spRP can be a treatment option for localized prostate cancer.Although epR-spRP still has a learning curve,it has advantages for postoperative pain and self-assessed cosmesis.In the absence of the single-port robotic surgery platform,we can still provide minimally invasive surgery for patients.