Brain organoids are new tool for drug screening of neurological diseases

At the level of in vitro drug screening,the development of a phenotypic analysis system with highcontent screening at the core provides a strong platform to support high-throughput drug screening.There are few systematic reports on brain organoids,as a new three-dimensional in vitro model,in terms of model stability,key phenotypic fingerprint,and drug screening schemes,and particula rly rega rding the development of screening strategies for massive numbers of traditional Chinese medicine monomers.This paper reviews the development of brain organoids and the advantages of brain organoids over induced neurons or cells in simulated diseases.The paper also highlights the prospects from model stability,induction criteria of brain organoids,and the screening schemes of brain organoids based on the characteristics of brain organoids and the application and development of a high-content screening system.

Effect of Polyisobutylene Succinimide on the Physical Stability of an Environmentally Friendly Pesticide Oil Dispersion Suspension

Oil dispersible suspension concentrates are safe,green,and environmentally friendly formulations.Problems such as layering,pasting,and bottoming are frequently encountered during the production,storage,and transportation process.Polyisobutylene succinimide functions as a dispersant and exhibits great potential to improve the physical stability of the oil dispersible suspension concentrate.From a microscopic perspective,the sorption characteristics of the polyisobutylene succinimide dispersant T151 on penoxsulam particle surfaces were comprehensively evaluated with XPS,FTIR,and SEM.The T151 adsorption procedure complied with a pseudo-second-order kinetic adsorption model,and it was a kind of physical sorption with an Ea of 22.57 kJ⋅mol^(−1).The T151 sorption model was consistent with the Langmuir isotherm.The adsorption process was spontaneous and followed by an entropy increase.TheΔH^(θ)of dispersant T151 on the surface of penoxsulam particles was 31.59 kJ⋅mol^(−1).The adsorption procedure was endothermic,and the primary force was hydrogen bonding.The XPS results showed that the F and S electronic peaks at the penoxsulam interface decreased,and that the C electronic peak increased significantly after the adsorption of dispersant T151,indicating the adsorption on the surface of penoxsulam particles.The results of this study provide a vital theoretical basis for the application of polyisobutylene succinimide dispersants in oil dispersible suspension systems.

Preparation and photodetection performance of high crystalline quality and large size β-Ga_(2)O_(3)microwires

Ultrawide band gap semiconductors are promising solar-blind ultraviolet(UV)photodetector materials due to their suitable bandgap,strong absorption and high sensitivity.Here,β-Ga_(2)O_(3)microwires with high crystal quality and large size were grown by the chemical vapor deposition(CVD)method.The microwires reach up to 1 cm in length and were single crystalline with low defect density.Owing to its high crystal quality,a metal–semiconductor–metal photodetector fabricated from a Ga_(2)O_(3)microwire showed a responsivity of 1.2 A/W at 240 nm with an ultrahigh UV/visible rejection ratio(R_(peak)/R_(400 nm))of 5.8×10^(5),indicating that the device has excellent spectral selectivity.In addition,no obvious persistent photoconductivity was observed in the test.The rise and decay time constants of the device were 0.13 and 0.14 s,respectively.This work not only provides a growth method for high-quality Ga_(2)O_(3)microwires,but also demonstrates the excellent performance of Ga_(2)O_(3)microwires in solar-blind ultraviolet detection.

Semisolid A356 alloy feedstock poured through a serpentine channel

Fine spheroidal and equiaxed nondendritic microstructures required for semisolid casting can be formed through a serpentine pouring channel.Effects of the pouring temperature and the vertical section length of the serpentine pouring channel were studied.The results indicate that both favorable semisolid microstructures of A356 aluminum alloy can be generated by a serpentine pouring channel,and the solid shell inside the channel can be avoided when the pouring temperature is in the range from 660 to 680°C.It is also shown that the vertical section length of the serpentine pouring channel has a significant influence on the microstructure of the feedstock,namely both the microstructure of the feedstock and the microstructure uniformity in the radial direction get worse when the vertical section length is shortened;moreover,the pouring temperature for obtaining the feedstock with suitable microstructure decreases.The relevant mechanisms were discussed.

Microstructural characteristics and mechanical properties of bobbin-tool friction stir welded 2024–T3 aluminum alloy

Cold-rolled 2024–T3 sheet alloy was subjected to bobbin-tool friction stir welding(BTFSW). The microstructural characteristics and mechanical properties of the nugget zone in the as-welded state were investigated. The results show that the equiaxed grain size of BTFSW 2024–T3 alloy decreases from 7.6 to 2.8 μm as the welding speed is increased from 80 to 120 mm/min; in addition,fine grains are generated in the nugget zone and the size distribution is non-uniform. All Al_2 Cu Mg(S′) precipitates dissolve into the Al matrix,whereas Mn-rich phases confirmed as T phases(Al_(20)Cu_2Mn_3,Al_6 Mn,or Al_3Mn) remain unchanged. The optimized parameters for BTFSW are verified as the rotation speed of 350 r/min and the travel speed of 100 mm/min. The variations in precipitation and dislocation play more important roles than grain size in the nugget zone with respect to influencing the mechanical properties during the BTFSW process. After the BTFSW process,the fracture mode of base material 2024–T3 alloy transforms from ductile rupture to ductile-brittle mixed fracture.

Room temperature non-balanced electric bridge ethanol gas sensor based on a single ZnO microwire

In this paper,ultra-long and large-scaled ZnO microwire arrays are grown by the chemical vapor deposition method,and a single ZnO microwire-based non-balanced electric bridge ethanol gas sensor is fabricated.The experimental results show that the gas sensor has good repeatability,high response rate,short response,and recovery time at room temperature(25℃).The response rate of the gas sensor exposed to 90-ppm ethanol is about 93%,with a response time and recovery time are 0.3 s and 0.7 s respectively.As a contrast,the traditional resistive gas sensor of a single ZnO microwire shows very small gas response rate.Therefore,ethanol gas sensor based on non-balanced electric bridge can obviously enhance gas sensing characteristics,which provides a feasible method of developing the high performance ZnO-based gas sensor.

Key stress extraction and equivalent test method for hybrid DC circuit breaker

Firstly, relevant stress properties of millisecond level breaking process and microsecond level commutation process of hybrid HVDC circuit breaker are studied in detail on the basis of the analysis for the application environment and topological structure and operating principles of hybrid circuit breakers, and key stress parameters in transient state process of two time dimensions are extracted. The established digital simulation circuit for PSCAD/EMTDC device-level operation of the circuit breaker has verified the stress properties of millisecond level breaking process and microsecond level commutation process. Then, equivalent test method, circuits and parameters based on LC power supply are proposed on the basis of stress extraction. Finally, the results of implemented breaking tests for complete 200 kV circuit breaker, 100 kV and 50 kV circuit breaker units, as well as single power electronic module have verified the accuracy of the simulation circuit and mathematical analysis. The result of this paper can be a guide to electrical structure and test system design of hybrid HVDC circuit breaker.

Roles of three classic TCM formulae in inhibiting gastric cancer growth in mice

Objective:To explore the effects of three classic traditional Chinese medicine (TCM) formulae,Dahuang Huanglian Xiexin Decoction (DHXD),Fuzi Lizhong pills (FLP) and Liushen pills (LSP),in suppressing gastric cancer growth in mice and provide evidence for their clinical applications.Methods:MGC-803 cells (5 × 106 per mouse) were injected into the subcutaneous tissues of the neck and back of nude mice.One week later,the mice were divided into three batches (9 total groups) based on tumor size and a random number table.Within each batch,the mice were subdivided into control,low-and high-dose groups for the three classic formulae.After 21-d treatment,the mice were observed for their general conditions,and then sacrificed.Tumor tissues were harvested and weighed,and the tumor inhibition rate was calculated.Results:Compared with the control group,body weight in the low-and high-dose DHXD and FLP groups showed no significant change (P >.05),while the high-dose LSP group had significantly lower body weight (P =.049).Compared with the control group,the low-and high-dose DHXD groups showed no significant inhibitory effect on xenograft tumor growth (P >.05);lowdose FLP showed an inhibitory effect on tumor growth (P =.039),while high-dose LSP had a more significant effect (P =.004).Conclusions:DHXD did not inhibit xenograft tumor growth in mice.In contrast,low-dose FLP had a measurable inhibitory effect,and high-dose LSP more significantly suppressed xenograft tumor growth in mice.

Screening of Low Tar Flue Cured Tobacco Varieties

The main agronomic traits,economic traits,appearance quality,main chemical components,gas composition and physical parameters of 10 flue cured tobacco varieties were investigated in the experiment.And the field natural incidence of the main diseases was investigated.The results showed that main agronomic characters of the 10 varieties were in line with the breeding objectives,among which 5 varieties have good economic characters;5 varieties have good appearance quality;6 varieties have coordinated chemical composition and high potassium content;9 varieties have good smoke components and physical indicators.

Texture evolution behavior and anisotropy of 2A97 Al-Li alloy during recrystallization at elevated temperature

2A97 Al-Li alloy was cold-rolled to 2 mm and then thermally exposed at different temperatures for 1 h and at 723 K for different time,respectively.The texture evolution behavior and the anisotropy of 2A97 Al-Li alloy were investigated.The result shows that the{001}<120>and{011}<233>textures are the dominant recrystallization texture.The{124}<211>texture is the final recrystallization texture.In case of low-temperature thermal exposure(473,573 K),the{011}<211>texture is aggregated to the{112}<111>and{123}<634>textures.During the recrystallization at 723 K,the{001}<110>,{111}<112>and{011}<100>textures are the intermediate transition grain orientations.The concurrent precipitation of Al_(20)Cu_(2)Mn_(3)and Al_(3)Zr results in the occurrence of unusually sharp{011}<233>and{001}<120>texture components during recrystallization.The alloy with both recrystallization and deformation texture possesses the smallest anisotropic,and the texture is the direct reason that results in the anisotropy.

Comparisons and Improvements of Key Operating Characteristics of Current Source Converter Applied in HVDC System

Because of its controlled power factor and no commutation failure,current source converter(CSC)made up of reverse-blocking IGCTs(RB-IGCTs)offers broad application prospects in the field of HVDC system.Valve voltage and power operating range as the most important operating characteristics should be paid attention to but they are always contradictory.First,the relationship between valve voltage and modulation index is obtained.In particular,valve voltage of converter under the three typical modulation methods is compared,analyzed,and verified.Second,with the help of the independent control strategy and coordinated control strategy of both ends,power operating ranges of the three modulation methods are comprehensively analyzed and compared.Third,in order to solve power coupling at a low active power,the improved coordination control strategy at both ends in this paper is proposed and the relationships among active power,reactive power,DC current and phase angle difference are given in detail.Finally,a 500 kV/3 kA simulation system was built in PSCAD/EMTDC to obtain comparison results of the key operating characteristics of CSC under different modulation methods and the converter can realize unity power operation under random active power after adopting the improved coordinated control strategy,and DC current does not decrease to zero,verifying effectiveness of the coordinated control strategy.

用于高风险环境安全监测和可调热管理的具有分层核壳结构的耐化学品纱线

Chemical resistant textiles are vital for safeguarding humans against chemical hazards in various settings.such as industrialproduction,chemicalaccidents,laboratory activities,and road transportation.However,the ideal integration of chemical resistance,thermal and moisture management,and wearer condition monitoring in conventional chemically protective textiles remains challenging.Herein,the design,manufacturing,and use of stretchable hierarchical core-shell yarns(HCSYs)for integrated chemical resistance,moisture regulation,and smart sensing textiles are demonstrated.These yarns con-tain helically elastic spandex,wrapped silver-plated nylon,and surface-structuredpolytetrafluo-roethylene(PTFE)yarns and are designed and manufactured based on a scalable fabrication process.In addition to their ideal chemical resistance performance,HCSYs can function as multifunctional stretch-able electronics for real-time human motion monitoring and as the basic element of intelligent textiles.Furthermore,a desirable dynamic thermoregulation function is achieved by exploiting the fabric structure with stretching modulation.Our HCSYs may provide prospective opportunities for the future development of smart protective textiles with high durability,flexibility,and scalability.

海南岛景心角海滩老鼠艻(Spinifex littoreus)灌丛沙堆沉积及形态特征

灌丛沙堆是海岸带广泛发育的风积地貌,海南岛东北部海岸发育着典型的老鼠艻(Spinifex littoreus)灌丛沙堆。通过野外考察和室内实验,并结合气象数据对海南岛文昌海岸景心角海滩老鼠艻灌丛沙堆的形成动力条件、沉积物粒度、地球化学元素特征和形态进行系统分析。结果表明:稳定的向岸风以及开阔的沙质海滩是灌丛沙堆发育的基本条件;较低的风能环境和滩肩的"贝壳碎屑物带"是景心角灌丛沙堆规模较小的主要原因;景心角老鼠艻灌丛沙堆形态以锥型和蝌蚪型为主;与沙堆迎风坡相比,背风坡坡长对沙堆的长轴影响较大,而沙堆的长轴和迎风坡坡长则对沙堆高度的影响更突出;老鼠艻灌丛水平方向上的生长更能影响沙堆形态的发育。

Clinical observations of osteoporotic vertebral compression fractures by using mineralized collagen modified polymethylmethacrylate bone cement

To investigate the clinical outcomes of the treatment of osteoporotic vertebral compression fractures(OVCFs)by using mineralized collagen(MC)modified polymethylmethacrylate(PMMA)bone cement.52 cases(52 vertebras)who sustained OVCF treated with MC modified PMMA bone cement from July 2014 to December 2015 were reviewed retrospectively.All the cases(52 patients,52 vertebras)included 8 males and 44 females with an average age of 74.83(ranging from 57-to 90-years old).The visual analogue scale(VAS),vertebral body height,Cobb angle,CT values preand post-operation as well as incidence of complications were used to be observed.All the patients underwent the surgery were successfully followed-up with an average period of 13.54 months(ranging from 6 to 23 months).The patients can ambulate at the second day after the operation.The VAS scores 2 days after the operation and during the last follow-up were significantly decreased compared with that before the operation(P<0.05);the average vertebral height and local Cobb angle had significant recovery(P<0.05);the CT value of the treated vertebra significantly increased compared with that before the operation(P<0.05).MC with good osteogenic activity and degradation properties can effectively improve the mechanical properties and biocompatibility of the PMMA bone cement,thus obtain better clinical results.

Determination of damaged wheat kernels with hyperspectral imaging analysis

Hyperspectral imaging was applied to classify the damaged wheat kernels and healthy kernels.The spectral information was extracted from damaged wheat kernels and healthy kernels samples.The effective wavelengths were obtained from spectral of 865-1711 nm by X-loadings of principal component analysis(PCA)and successive projection algorithm(SPA)method,respectively.Partial least square method(PLS)and least square-support vector machine(LS-SVM)were then used to build classification models on full spectral data and effective wavelengths dataset,respectively.The results showed that the classification accuracy of every LS-SVM model was the best,being 100%.While the accuracy of the PLS model was slightly lower,still over 97%.The confusion matrix showed that several damaged wheat kernels samples were misclassified as healthy samples,while all healthy samples were correctly classified.The overall results indicated that hyperspectral imaging could be used for discriminating the damaged wheat kernels and could provide a reference for detecting other grain kernels grading degrees.Further,this study can provide a research basis for the development of online or portable detectors on grain damaged kernels recognition,which will be beneficial for grain grading or post-harvest quality processing of other grains.

Clinical observation of mineralized collagen bone grafting after curettage of benign bone tumors

Curettage of benign bone tumor is a common cause for bone defect.For such bone defect repair,autogenous bone,allogeneic bone and traditional artificial bone graft substitutes have many disadvantages.In recent years,a biomimetic mineralized collagen(MC)with similar composition and microstructures to the natural bone matrix was developed and used for treating various bone defects.In this work,a retrospective study analyzed clinical outcomes of patients treated with curettage of benign bone tumors and bone grafting with MC,in comparison to another group treated with the same surgical method and autogenous bone.Lane-Sandhu X-ray score of the autogenous bone group was superior to the MC group at 1 month after the operation,but the two groups had no statistical difference at 6 and 12 months.The MC group was better in Musculoskeletal Tumor Society scoring at 1 and 6 months after the operation,and the two groups had no statistical difference at 12 month.Therefore,the MC performed not as good as autogenous bone in early stage of bone healing but achieved comparable outcomes in long-term follow-ups.Moreover,the MC has advantages in function recovery and avoided potential complications induced by harvesting autogenous bone.

Isothermal crystallization of polypropylene/surface modified silica nanocomposites

In the present work, 3-methacryloxypropyltrimethoxy-silane silanized silica(SiO_2-WD70) and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide immobilized silica(SiO_2-WD70-DOPO) nanoparticles were prepared. Silica, SiO_2-WD70 and SiO_2-WD70-DOPO were incorporated into polypropylene(PP) by melt compounding. Differential scanning calorimetry(DSC), X-ray diffraction(XRD) and polarized optical microscopy(POM) were employed to investigate the isothermal crystallization behavior of PP and PP/silica composites. The kinetic constant(kn), and half crystallization time(t1/2) were calculated by Avrami equation,while the surface free energy of folding was calculated by Lauritzen-Hoffman theory. The increased kn, decreased t1/2 and the surface free energy(σe) in the order of PP, PP/SiO_2, PP/SiO_2-WD70 and PP/SiO_2-WD70-DOPO nanocomposites were attributed to the surface modification of silica. XRD indicated that SiO_2-WD70-DOPO addition had no effect on PP crystal structure but accelerated the crystallization rate. POM determined that SiO_2-WD70-DOPO addition promoted the nucleation of PP by inducing a higher nucleation density during isothermal conditions. The surface modified nanoparticle SiO_2-WD70-DOPO might find possible application as a new type of inorganic nano-sized nucleation agent for PP.

Development of a multi-adaptive feeding device for automated plug seedling transplanter

In order to improve the adaptability of the seedling feeding devices to different plug trays for various seedlings,a multi-adaptive plug seedling feeding device for automatic field transplantation was developed.Its efficiency and adaptability have been improved using a seedling delivery device equipped with a row of end-effectors,which were provided with continuous plug seedlings by a compact seedling tray conveyor carrying out a reciprocating action.Each operation for the seedling feeding device could work automatically through a control system.Three categories of plug seedlings,cucumber,pepper and tomato seedlings were tested.The results of the performance test for the prototype demonstrated that the best performance emerged in the cucumber seedlings in 50-cell trays with the highest success rate of 88%at the feeding frequency of 6 groups/min.The lowest success rate was 73.33%for the tomato seedlings in 105-cell trays at the feeding frequency of 12 groups/min.It can be concluded that the automated feeding device developed in this study could be used for various plug seedlings as a result of its strong adaptability.

APPL2 Negatively Regulates Olfactory Functions by Switching Fate Commitments of Neural Stem Cells in Adult Olfactory Bulb via Interaction with Notch1 Signaling

Adult olfactory neurogenesis plays critical roles in maintaining olfactory functions.Newly-generated neurons in the subventricular zone migrate to the olfactory bulb(OB) and determine olfactory discrimination,but the mechanisms underlying the regulation of olfactory neurogenesis remain unclear.Our previous study indicated the potential of APPL2(adaptor protein,phosphotyrosine interacting with PH domain and leucine zipper 2) as a modulating factor for neurogenesis in the adult olfactory system.In the present study,we report how APPL2 affects neurogenesis in the OB and thereby mediates olfactory discrimination by using both in vitro neural stem cells(NSCs) and an in vivo animal model-APPL2 transgenic(Tg) mice.In the in vitro study,we found that APPL2 overexpression resulted in NSCs switching from neuronal differentiation to gliogenesis while APPL2 knockdown promoted neurogenesis.In the in vivo study,APPL2 Tg mice had a higher population of glial cells and dampened neuronal production in the olfactory system,including the corpus callosum,OB,and rostral migratory stream.Adult APPL2 Tg mice displayed impaired performance in olfactory discrimination tests compared with wild-type mice.Furthermore,we found that an interaction of APPL2 with Notch1 contributed to the roles of APPL2 in modulating the neurogenic lineage-switching and olfactory behaviors.In conclusion,APPL2 controls olfactory discrimination by switching the fate choice of NSCs via interaction with Notch1 signaling.

Canonical and early lineage-specific stem cell types identified in planarian SirNeoblasts

Background:The pluripotent stem cells in planarians,a model for tissue and cellular regeneration,remain further identification.We recently developed a method to enrich piwi-1+cells in Schmidtea mediterranea,by staining cells with SiR-DNA and Cell Tracker Green,named SirNeoblasts that permits their propagation and subsequent functional study in vivo.Since traditional enrichment for planarian neoblasts by Hoechst 33342 staining generates X1 cells,blocking the cell cycle and inducing cytotoxicity,this method by SiR-DNA and Cell Tracker Green represents a complementary technological advance for functional investigation of cell fate and regeneration.However,the similarities in heterogeneity of cell subtypes between SirNeoblasts and X1 remain unknown.Results:In this work,we performed single cell RNA sequencing of SirNeoblasts for comparison with differential expression patterns in a publicly available X1 single cell RNA sequencing data.We found first that all of the lineagespecific progenitor cells in X1 were present in comparable proportions in SirNeoblasts.In addition,SirNeoblasts contain an early muscle progenitor that is unreported in X1.Analysis of new markers for putative pluripotent stem cells identified here,with subsequent sub-clustering analysis,revealed earlier lineages of epidermal,muscular,intestinal,and pharyngeal progenitors than have been observed in X1.Using the gcm as a marker,we also identified a cell subpopulation resided in previously identified tgs-1+neoblasts.Knockdown of gcm impaired the neoblast repopulation,suggesting a function of gcm in neoblasts.Conclusions:In summary,the use of SirNeoblasts will enable broad experimental advances in regeneration and cell fate specification,given the possibility for propagation and transplantation of recombinant and mutagenized pluripotent stem cells that are not previously afforded to this rapid and versatile model system.