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In 4H-silicon carbide crystals, basal plane slip is the predominant deformation mechanism. However, prismatic slip is often observed in single crystals grown by the physical vapor transport method as the diameter expands to 6 inches or larger. Thermal modeling has shown that occurrence of prismatic slip is attributed to increased radial thermal gradients. While X-ray topography can be used to characterize the presence and extent of prismatic slip, the feasibility of using the chemical etching method to assess the extent of prismatic slip in an industrial setting is investigated. The distribution of scallop shaped etch pits oriented along the directions that correspond to prismatic dislocations, correlate well with the results of the thermal model that predicts the occurrence of prismatic slip dislocations. This capability of the etch pit method to characterize prismatic slip can be used to manage radial thermal gradients during PVT growth.

The main pathological characteristics of demyelinating diseases are central nervous system (CNS) myelin damage, and the differentiation of oligodendrocyte precursor cells is the therapeutic target of myelin repair. Previous studies have found that a large number of platelet-derived growth factor receptor α(PDGFRα) positive oligodendrocyte progenitor cells (OPCs) accumulate in the lesion area of myelin injury, and differentiation is blocked. However, the therapeutic effects of drugs currently used clinically on OPCs differentiation and myelin repair are limited. The main reason is that it is difficult to reach the effective concentration of the drug in the lesion area. Therefore, efficiently delivering into the CNS lesion area is of great significance for the treatment of MS. Natural exosomes have good biocompatibility and are ideal drug carriers. The delivery of drugs to lesion areas can be achieved by giving the exosomes armed targeting ligand. Therefore, in this study, combining exosomes with PDGFA helps them accumulate in OPCs in vitro and in vivo. Further, load montelukast into exosomes to achieve targeted therapy for cuprizone-induced demyelination animal model. The implementation of this research will help provide effective treatments for demyelinating diseases and lay a theoretical foundation for its application in the clinical treatment of different demyelinating diseases.

Anacardic acid (AA) is a phenolic acid extract found in a number of plants, crops, and fruits. It exhibits a wide range of biological activities. This study displayed that AA effectively alleviated EAE, a classical mouse model of multiple sclerosis. AA administered to the EAE greatly decreased inflammatory cell infiltration to the CNS and protected the myelin integrity in the white matter of the spinal cord. AA could block lipopolysaccharide-induced DC activation. inhibited the polarization of 2D2 mice-derived T cells by inhibiting the DCs activity. Immunoblot results indicated that the phosphorylation of NF-κB is significantly suppressed in AA-treated DCs. This work displayed that AA possessed a potential anti-inflammatory therapeutic effect for the treatment of autoimmune disease.

Liver metastasis is not rare during the course of neuroendocrine neoplasms.The methods for treating neuroendocrine neoplasm with liver metastasis(NENLM)are diversifying,which exposes the limitations of the early therapeutic response assessment based on only morphological changes.The emerging imaging biomarkers can sensitively describe changes in response to treatment from the functional level,providing new ideas for the therapeutic response evaluation of NENLM.In this paper,we reviewed the status quo and the latest research progress of imaging assessment for early therapeutic response of NENLM,aiming to provide reference for assessing the response and further exploring the treatment-related biomarkers.

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system that is mainly mediated by pathological T-cells. Experimental autoimmune encephalomyelitis (EAE) is a well-known animal model of MS that is used to study the underlying mechanism and offers a theoretical basis for developing a novel therapy for MS. Good therapeutic effects have been observed after the administration of natural compounds and their derivatives as treatments for EAE. However, there has been a severe lag in the research and development of drug mechanisms related to MS. This review examines natural products that have the potential to effectively treat MS. The relevant data were consulted in order to elucidate the regulated mechanisms acting upon EAE by the flavonoids, glycosides, and triterpenoids derived from natural products. In addition, novel technologies such as network pharmacology, molecular docking, and high-throughput screening have been gradually applied in natural product development. The information provided herein can help improve targeting and timeliness for determining the specific mechanisms involved in natural medicine treatment and lay a foundation for further study.

Cucumber monoculture could cause soil salinization and acidification, soilborne diseases, and eventually yield loss. However, after a 25-year monoculture in Wafangdian county, Liaoning province, China, cucumber yields have remained satisfactory. In the present study, we investigated how the soil abiotic and biotic properties, in addition to soil rhizosphere microbial community structure in the greenhouses, could still sustain plant growth after such long-term monoculture production. Soil organic carbon, total nitrogen, and available nitrogen were accumulated significantly after monoculture. Such increasing soil fertility was accompanied by increased soil microbial abundance, which reshaped soil microbial community structure. Both bacterial and fungal diversity, including observed and estimated richness, Heip evenness, and Shannon diversity, decreased significantly, while the monoculture period had a greater influence on fungal diversity than on bacterial diversity. Although the high accumulation of soil nutrients increased soil salinity and acidity, the abundance of potential plant pathogenic fungi did not show an obvious increase. These results indicated that maintaining soil abiotic and biotic properties using organic fertilizers and balanced chemical fertilizers, especially improving potassium fertilizer application, could be useful measurements for the sustainable development of greenhouse vegetable production. In addition, appropriate management strategies should be considered to reduce the potential risk of soil salinization.

To compare the plasma components of frozen plasma (FP) and fresh frozen plasma (FFP).Twenty samples of FP and 20 samples of FFP from Beijing Red Cross Blood Center were randomly selected. Immediately after plasma melting, 12 plasma components including coagulation factor, fibrinolytic system and anticoagulation protein were detected, including activated partial thromboplastin time (APTT), prothrombin time (PT), coagulation factor Ⅷ (FⅧ) activity, coagulation factor Ⅴ (FⅤ) activity, fibrinogen(FIB) level, ADAMTS-13 activity, von Willebrand factor(vWF) activity, D-dimer (D-dimer, DD), fibrin degradation products (FDP), antithrombin (AT), protein C (PC), and protein S (PS). All these coagulation components between the two types of plasma were compared and analyzed.Compared with FFP, APTT in FP was significantly prolonged(t=3.428, P0.01), and PT was also significantly prolonged(z=-2.140, P0.05), and FⅧ activity was decreased (t=-3.372, P0.01), but all in the reference range, and PS activity was decreased(t=-2.458，P＜0.05), there was no statistical difference in the other part between two types of plasma(P0.05).FP can substitute FFP in the treatment of some diseases, although it is lack of some coagulation factors and anticoagulation protein.普通冰冻血浆与新鲜冰冻血浆部分血浆组分的比较.比较普通冰冻血浆（FP）和新鲜冰冻血浆（FFP）中血浆组分的差异.随机选择北京市红十字血液中心提供的FP和FFP各20份，血浆融化后即刻分别检测凝血因子、纤溶系统及抗凝蛋白指标等12种血浆组分，即活化的部分凝血活酶时间（APTT）、凝血酶原时间（PT）、凝血因子Ⅷ（FⅧ）活性、凝血因子Ⅴ（FⅤ）活性、纤维蛋白原（FIB）水平、血管性血友病因子裂解蛋白酶（ADAMTS-13）活性、血管性血友病因子（vWF）活性、D-二聚体（D-dimer, DD）、纤维蛋白降解产物（fibrin degradation products, FDP）、抗凝血酶（antithrombin , AT）、蛋白C（protein C, PC）、蛋白S（protein S, PS），并进行比较分析.与FFP相比，FP中APTT明显延长（t=3.428, P0.01），PT延长（z=-2.140, P0.05），FⅧ 活性明显降低（t=-3.372, P0.01），但均在参考区间内；PS 活性降低（t=-2.458，P＜0.05）；两种血浆中其余组分的差异无统计学意义（P0.05）.与FFP相比，FP缺乏某些凝血因子和抗凝蛋白，但可替代FFP应用于部分疾病的治疗.

Additional file 1. The supplementary figures and tables of trends in MDR-TB from 1990 to 2017.

The lack of targeted and high-efficiency drug delivery to the central nervous system (CNS) nidus is the main problem in the treatment of demyelinating disease. Extracellular vesicles (EVs) possess great promise as a drug delivery vector given their advanced features. However, clinical applications are limited because of their inadequate targeting ability and the “dilution effects” after systemic administration. Neural stem cells (NSCs) supply a plentiful source of EVs on account of their extraordinary capacity for self-renewal. Here, we have developed a novel therapeutic system using EVs from modified NSCs with high expressed ligand PDGF-A (EVPs) and achieve local delivery. It has been demonstrated that EVPs greatly enhance the target capability on oligodendrocyte lineage. Moreover, EVPs are used for embedding triiodothyronine (T3), a thyroid hormone that is critical for oligodendrocyte development but has serious side effects when systemically administered. Our results demonstrated that systemic injection of EVPs + T3, versus EVPs or T3 administration individually, markedly alleviated disease development, enhanced oligodendrocyte survival, inhibited myelin damage, and promoted myelin regeneration in the lesions of experimental autoimmune encephalomyelitis mice. Taken together, our findings showed that engineered EVPs possess a remarkable CNS lesion targeting potential that offers a potent therapeutic strategy for CNS demyelinating diseases as well as neuroinflammation., Graphical abstract Schematic representation of EVPs + T3 treatment ameliorated disease development and promoted myelin regeneration.Image 1, Highlights • NSC-derived EV-PDGFA dramatically increased targeting efficiency to the lineage of OLGs and the demyelinated area in the CNS. • EVPs-T3 exert the therapeutic ability in the lesion suppressed the disease development and protected myelin loss. • EVPs-T3 increased numbers of OLGs in the lesion and TEM data evidenced that EVPs-T3 promotes myelin regeneration in vivo.

This paper summarizes the general steps and methods of electric vehicle charging facility planning, and puts forward a simple and feasible model. Markov prediction based on the travel rules of electric vehicle users to obtain the spatiotemporal distribution of charging demand; The minimum comprehensive cost model is established and solved by genetic algorithm. Finally, the technical principles of electric vehicle charging facility planning are summarized.

The impact of large-scale access of electric vehicles on the power distribution network of electric power systems has become increasingly prominent. To solve the problems brought by electric vehicle charging to the distribution system, it is particularly important to predict the charging load of electric vehicles. Based on the travel chain theory, this paper models the charging demand of household electric vehicles. Considering the uncertainty of charging demand in space and time, combined with the Monte Carlo method, taking the typical IEEE33 node power distribution system as an example, this paper simulates the impact of electric vehicle charging load access on the distribution network under different penetration rates and different access modes. The research results show that the charging load of household electric vehicles is usually concentrated in residential areas, and the impact on the overall load characteristics of the distribution network and the node voltage offset is more significant as the penetration rate of electric vehicles increases

Additional file 2: Table S1.The summary of samples collection, grouping and sequencing results.

The draft genome of Bacillus velezensis strain B6, a rhizobacterium with good biocontrol performance isolated from soil in China, was sequenced. The assembly comprises 32 scaffolds with a total size of 3.88 Mb. Gene clusters coding either ribosomally encoded bacteriocins or nonribosomally encoded antimicrobial polyketides and lipopeptides in the genome may contribute to plant disease control.

High speed encoder is the key element of high speed analog-to-digital converter (ADC). Therefor the type of encoder, the type of code, bubble error suppression and bit synchronization must be taken into careful consideration especially for folding and interpolating ADC. To reduce the bubble error which may resulted from the circuit niose, comparator metastability and other interference, the output of quantizer is first encoded with gray code and then converted to binary code. This high speed encoder is verified in the whole time-interleaved ADC with 0.18 Bi-CMOS technology, the whole ADC can achieve a SNR of 45 dB at the sampling rate of 5GHz and input frequency of 495MHz, meanwhile a bit error rate (BER) of less than 10-16 is ensured by this design.

In this paper, we present an 8-bit 5 Gsample/s time-interleaved analog-to-digital converter (TI ADC). A 4-phase low jitter clock is designed to control four 1.25 Gsample/s sub-ADCs which is implemented using folding and interpolating architecture. Digital calibration is used to adjust the offset error and gain error of sub-ADCs. Meanwhile, serial peripheral interface (SPI) is adopted to adjust mismatch of gain and sample time between sub-ADCs. The whole TI ADC is designed using a 0.18m SiGe BiCMOS process. The whole ADC has a SNR of about 45 dB at the input frequency of 495 MHZ and an equivalent ENOB of 7.2 bits.

This research was conducted in Huanghuadianzi watershed in Aohan, Chifeng, Inner Mongolia. Geostatistic was used to study the spatial distribution of soil nitrogen and their affecting factors. The results showed that the soil nitrogen contents in all layers distributed as an island shape, and the high value areas were mainly distributed in the northwest of the watershed as an obvious fertile island shape, while the low value areas were mainly distributed in the south of the watershed. Nitrogen was mainly concentrated in the surface soil, and its content decreased with the increase of soil depth. The soil nitrogen content at first increased then decreased with the altitude, decreased with the slope, and showed the order of shady slopesemi-shady slopesemi-sunny slopesunny slope in different aspects. The average soil nitrogen contents in different land use types ranked as croplandwoodlandgrassland.

The resolution of aerial images was low, because the aviation aerospace camera was far from the scenery when shooting. In order to see the object of the aviation images clearly,the aviation images should be enlarged to improve the resolution . As the complexity and irregularity of the aerial images, the texture features is lost and considerable error is caused by using the traditional methods. In this article, the fractal interpolation has been used to enlarge the images, which can not only overcome the shortcoming of the linear interpolation, but also maintain the fine texture features of the original images, which is helpful to obtain higher accuracy than the traditional interpolation.

With the development and application of computer science and technology innovation, artificial intelligence industry has achieved sharp development, and its technology has been widely used in many fields, such as natural language processing, robot manufacturing, semantic recognition, information system development, etc. In terms of natural language processing, the recognition and understanding of human language based on artificial intelligence has become the focus of research. And as semantic recognition and processing play an important part of natural language processing, they have achieved satisfactory results in the Abstract Meaning Representation (AMR) and Vector Space Model (VSM) development and application. Based on this, this paper takes the English recognition as the research object, adopts the scientific research methods such as literature analysis, practice investigation and experimental research, further analyzes English semantic recognition based on AMR and VSM from the aspects of semantic recognition difficulty, principles of AMR and VSM and its application in English recognition, as well as the practical applications. The author hopes to provide references for future research.