Effects of intravenous rtPA in patients with minor stroke

BACKGROUND

Whether minor ischemic stroke (MIS) patients can benefit from intravenous thrombolysis (IVT) remains controversial. The association between the efficacy of IVT and baseline National Institute of Health Stroke Scale (NIHSS) score is unclear in MIS, while the association in moderate and severe stroke is known. This study aimed to explore the effect of IVT in patients with MIS and analyze its efficacy in patients with different baseline NIHSS scores.

METHODS

Patients with a NIHSS score ≤5 within 4.5 h of stroke onset were screened in 32 centers. Patients with and without IVT were matched to a ratio of 1:1 with propensity scores. An excellent outcome was defined as a modified Rankin Scale (mRS) score ≤1 at three months after stroke onset. Safety outcomes included mortality and symptomatic intracranial hemorrhage (sICH). Multivariate analysis was used to compute the adjusted odds ratio (OR) for excellent outcomes. The effect of IVT was further analyzed in subgroups according to the baseline NIHSS score.

RESULTS

Of the 23,853 screened, 3336 patients with MIS who arrived at the hospital within 4.5 h of onset were included. The 1163 patients treated with IVT were matched with 1163 patients without IVT. IVT in minor strokes generated an adjusted OR of 1.38 (95% CI: 1.09-1.75, p = 0.009) for excellent outcomes. There were no significant differences in mortality (0.17% vs. 0.09%, p = 1.000) and sICH (0.69% vs. 0.86%, p = 0.813) between patients with and without IVT. Subgroup analysis showed that there was no significant effect of IVT in the baseline NIHSS 0-1 or 2-3 subgroups, with adjusted OR of 0.816 (95% CI 0.437-1.53, p = 0.525) and1.22 (95% CI 0.845-1.77, p = 0.287), respectively. In patients with NIHSS score of 4-5, IVT was significantly effective, with an adjusted OR of 1.53 (95% CI 1.02-2.30, p = 0.038).

CONCLUSION

IVT can improve MIS outcomes. The risks of sICH and mortality did not increase, especially in patients with NIHSS scores 4 to 5, who could benefit from IVT significantly.

Ultrathin High-Entropy Fe-Based Spinel Oxide Nanosheets with Metalloid Band Structures for Efficient Nitrate Reduction toward Ammonia

Spinel oxides with tunable chemical compositions have emerged as versatile electrocatalysts, however their performance is greatly limited by small surface area and low electron conductivity. Here, ultrathin high-entropy Fe-based spinel oxides nanosheets are rationally designed (i.e., (Co0.2Ni0.2Zn0.2Mg0.2Cu0.2)Fe2O4; denotes A5Fe2O4) in thickness of ≈4.3 nm with large surface area and highly exposed active sites via a modified sol-gel method. Theoretic and experimental results confirm that the bandgap of A5Fe2O4 nanosheets is significantly smaller than that of ordinary Fe-based spinel oxides, realizing the transformation of binary spinel oxide from semiconductors to metalloids. As a result, such A5Fe2O4 nanosheets manifest excellent performance for the nitrate reduction reaction (NO3 -RR) to ammonia (NH3), with a NH3 yield rate of ≈2.1 mmol h-1 cm-2 at -0.5 V versus Reversible hydrogen electrode, outperforming other spinel-based electrocatalysts. Systematic mechanism investigations reveal that the NO3 -RR is mainly occurred on Fe sites, and introducing high-entropy compositions in tetrahedral sites regulates the adsorption strength of N and O-related intermediates on Fe for boosting the NO3 -RR. The above findings offer a high-entropy platform to regulate the bandgap and enhance the electrocatalytic performance of spinel oxides.

Bridging Together Theoretical and Experimental Perspectives in Single-Atom Alloys for Electrochemical Ammonia Production

Ammonia is an essential commodity in the food and chemical industry. Despite the energy-intensive nature, the Haber-Bosch process is the only player in ammonia production at large scales. Developing other strategies is highly desirable, as sustainable and decentralized ammonia production is crucial. Electrochemical ammonia production by directly reducing nitrogen and nitrogen-based moieties powered by renewable energy sources holds great potential. However, low ammonia production and selectivity rates hamper its utilization as a large-scale ammonia production process. Creating effective and selective catalysts for the electrochemical generation of ammonia is critical for long-term nitrogen fixation. Single-atom alloys (SAAs) have become a new class of materials with distinctive features that may be able to solve some of the problems with conventional heterogeneous catalysts. The design and optimization of SAAs for electrochemical ammonia generation have recently been significantly advanced. This comprehensive review discusses these advancements from theoretical and experimental research perspectives, offering a fundamental understanding of the development of SAAs for ammonia production.

High temperature stress induced oxidative stress, gut inflammation and disordered metabolome and microbiome in tsinling lenok trout

Tsinling lenok trout (Brachymystax lenok tsinlingensis Li) is a species of cold-water salmon that faces serious challenges due to global warming. High temperature stress has been found to damage the gut integrity of cold-water fish, impacting their growth and immunity. However, limited research exists on the causal relationship between gut microbial disturbance and metabolic dysfunction in cold-water fish induced by high temperature stress. To address this gap, we conducted a study to investigate the effects of high temperature stress (24 °C) on the gut tissue structure, antioxidant capacity, gut microorganisms, and metabolome reactions of tsinling lenok trout. Our analysis using 16 S rDNA gene sequencing revealed significant changes in the gut microbial composition and metabolic profile. Specifically, the abundance of Firmicutes and Gemmatimonadetes decreased significantly with increasing temperature, while the abundance of Bacteroidetes increased significantly. Metabolic analysis revealed a significant decrease in the abundance of glutathione, which is synthesized from glutamate and glycine, under high temperature stress. Additionally, there was a notable reduction in the levels of adenosine, inosine, xanthine, guanosine, and deoxyguanosine, which are essential for DNA/RNA synthesis. Conversely, there was a significant increase in the abundance of D-glucose 6 P. Furthermore, high temperature stress adversely affects intestinal structure and barrier function. Our findings provide valuable insights into the mechanism of high temperature stress in cold-water fish and serve as a foundation for future research aimed at mitigating the decline in production performance caused by such stress.

Single Cell Analysis of Macrophage Heterogeneity and NK-Cell Exhaustion in Lewis Lung Cancer Xenograft Tumor

PURPOSE/OBJECTIVE(S)

Stereotactic body radiation therapy (SBRT) has attracted much attention because of its ability to stimulate anti-tumor immune response. However, the mechanism of SBRT reprogramming the tumor microenvironment remains to be elucidated.

MATERIALS/METHODS

Using Lewis lung carcinoma (LLC) xenograft mice model treated with SBRT (8Gy x 3F), multiplex assay was performed to measure serum chemokine levels, and single-cell RNA sequencing was performed to assess tumor microenvironment. The differential expression genes of each cell subcluster were identified by the "Find-All markers" function with default parameters provided by Seurat. Intercellular communication analysis was explored by using CellPhone DB package.

RESULTS

The majority of serum chemokines involved macrophage recruitment, including CCL3, CCL4, CCL8, and CCL20, were highly secreted at 7 days after SBRT. Single-cell RNA sequencing of 108,741 cells were contained from 6 mouse Lewis lung carcinoma samples (n = 3 tumors for SBRT, n = 3 tumors pooled for SHAM). Besides Lewis cancer cells, myeloid cells were 57.61% ,70.82% in Sham-irradiation (SHAM) and SBRT while NT and T cells were 20.50%, 7.81% in SHAM and SBRT, respectively. When compared with SHAM group, upregulation of Ccl3, Ccl4, Ccl8 chemokine genes were observed in cancer cells of SBRT group. Differential expression genes analysis showed high expression level of Ccl8 (Log2FC 2.54, p<0.01) in cluster of Mrc1+macrophage. The SBRT group consisted of more Ccl8+Mrc1+macrophages (proportion 36.28% for SBRT, 27.44% for SHAM) and exhausted NK cells (proportion 22.56% for SBRT, 13.70% for SHAM). More importantly, intercellular communication analysis revealed a potential communication network between Ccl8+Mrc1+macrophages and exhausted NK cells.

CONCLUSION

Our results provide a potential therapeutic strategy by disrupting Ccl8+ Mrc1+macrophages and NK-cell interaction to facilitate the stimulation of the anti-tumor immune response by SBRT.

High-Flux Neutron Generator Based on Laser-Driven Collisionless Shock Acceleration

A novel compact high-flux neutron generator with a pitcher-catcher configuration based on laser-driven collisionless shock acceleration (CSA) is proposed and experimentally verified. Different from those that previously relied on target normal sheath acceleration (TNSA), CSA in nature favors not only acceleration of deuterons (instead of hydrogen contaminants) but also increasing of the number of deuterons in the high-energy range, therefore having great advantages for production of high-flux neutron source. The proof-of-principle experiment has observed a typical CSA plateau feature from 2 to 6 MeV in deuteron energy spectrum and measured a forward neutron flux with yield 6.6×10^{7}  n/sr from the LiF catcher target, an order of magnitude higher than the compared TNSA case, where the laser intensity is 10^{19}  W/cm^{2}. Self-consistent simulations have reproduced the experimental results and predicted that a high-flux forward neutron source with yield up to 5×10^{10}  n/sr can be obtained when laser intensity increases to 10^{21}  W/cm^{2} under the same laser energy.

Emerging Trends of Carbon-Based Quantum Dots: Nanoarchitectonics and Applications

Carbon-based quantum dots (QDs) have emerged as a fascinating class of advanced materials with a unique combination of optoelectronic, biocompatible, and catalytic characteristics, apt for a plethora of applications ranging from electronic to photoelectrochemical devices. Recent research works have established carbon-based QDs for those frontline applications through improvements in materials design, processing, and device stability. This review broadly presents the recent progress in the synthesis of carbon-based QDs, including carbon QDs, graphene QDs, graphitic carbon nitride QDs and their heterostructures, as well as their salient applications. The synthesis methods of carbon-based QDs are first introduced, followed by an extensive discussion of the dependence of the device performance on the intrinsic properties and nanostructures of carbon-based QDs, aiming to present the general strategies for device designing with optimal performance. Furthermore, diverse applications of carbon-based QDs are presented, with an emphasis on the relationship between band alignment, charge transfer, and performance improvement. Among the applications discussed in this review, much focus is given to photo and electrocatalytic, energy storage and conversion, and bioapplications, which pose a grand challenge for rational materials and device designs. Finally, a summary is presented, and existing challenges and future directions are elaborated.

Borophene Embedded Cellulose Paper for Enhanced Photothermal Water Evaporation and Prompt Bacterial Killing

Solar-driven photothermal water evaporation is considered an elegant and sustainable technology for freshwater production. The existing systems, however, often suffer from poor stability and biofouling issues, which severely hamper their prospects in practical applications. Conventionally, photothermal materials are deposited on the membrane supports via vacuum-assisted filtration or dip-coating methods. Nevertheless, the weak inherent material-membrane interactions frequently lead to poor durability, and the photothermal material layer can be easily peeled off from the hosting substrates or partially dissolved when immersed in water. In the present article, the discovery of the incorporation of borophene into cellulose nanofibers (CNF), enabling excellent environmental stability with a high light-to-heat conversion efficiency of 91.5% and water evaporation rate of 1.45 kg m^-2 h^-1 under simulated sunlight is reported. It is also demonstrated that borophene papers can be employed as an excellent active photothermal material for eliminating almost 100% of both gram-positive and gram-negative bacteria within 20 min under three sun irradiations. The result opens a new direction for the design of borophene-based papers with unique photothermal properties which can be used for the effective treatment of a wide range of wastewaters.

Surface acoustic wave induced phenomena in two-dimensional materials

Surface acoustic wave (SAW)-matter interaction provides a fascinating key for inducing and manipulating novel phenomena and functionalities in two-dimensional (2D) materials. The dynamic strain field and piezo-electric field associated with propagating SAWs determine the coherent manipulation and transduction between 2D excitons and phonons. Over the past decade, many intriguing acoustic-induced effects, including the acousto-electric effect, acousto-galvanic effect, acoustic Stark effect, acoustic Hall effect and acoustic exciton transport, have been reported experimentally. However, many more phenomena, such as the valley acousto-electric effect, valley acousto-electric Hall effect and acoustic spin Hall effect, were only theoretically proposed, the experimental verification of which are yet to be achieved. In this minireview, we attempt to overview the recent breakthrough of SAW-induced phenomena covering acoustic charge transport, acoustic exciton transport and modulation, and coherent acoustic phonons. Perspectives on the opportunities of the proposed SAW-induced phenomena, as well as open experimental challenges, are also discussed, attempting to offer some guidelines for experimentalists and theorists to explore the desired exotic properties and boost practical applications of 2D materials.

The association between serum orexin A and short-term neurological improvement in patients with mild to moderate acute ischemic stroke

BACKGROUND

The serum orexin A level was significantly lower among patients with acute ischemic stroke (AIS) and negatively related to the volume of the infarction, but the relationship between serum orexin A and prognosis of AIS was still unclear. We aimed to clarify the association between serum orexin A and the short-term neurological improvement in patients with mild to moderate AIS.

METHODS

We consecutively enrolled patients with first ever mild to moderate AIS admitted to hospital within 48 h from symptom onset in this prospective observational study. The serum orexin A concentrations were determined on the second morning since the admission. The short-term neurological improvement was defined as more than 1 point decrease in the National Institute of Health Stroke Scale score within 7 days after admission.

RESULTS

We detected increased serum orexin A level in mild to moderate AIS patients with early onset of stroke-related insomnia (33.44 vs 18.66 pg/ml, p = .004) as well as in patients with short-term neurological improvement compared to those without improvement (31.78 vs 16.24 pg/ml, p = .038). The serum orexin A level was positively associated with the short-term neurological improvement after adjusting for sleep condition and other related variables.

CONCLUSION

Serum orexin A might be a useful biomarker for the assessment of early prognosis in patients with mild to moderate AIS.

Clinical factors associated with cerebral autoregulation in ischemic stroke related to small artery occlusion

Background

Existing data suggest that cerebral autoregulation (CA) varies among different subtypes of ischaemic stroke. CA is globally impaired in patients with small artery occlusion (SAO). However, the factors influencing CA impairment in patients remains to be elucidated.

Methods

Stroke patients with SAO who underwent brain magnetic resonance imaging (MRI) were prospectively studied. Within 7 days after stroke onset, CA was recorded from the middle cerebral artery blood flow velocity and arterial blood pressure was simultaneously measured. Transfer function analysis was used to derive CA parameters, including gain and phase. Clinical characteristics, mean arterial pressure (MAP), biochemical findings, and cerebral small vessel disease (CSVD) markers on MRI were assessed in each patient. Factors associated with CA parameters were investigated. Univariate and multivariate linear regression analyses were conducted to determine the relationship between clinical factors and CA parameters.

Results

Sixty-three SAO patients (age, 56.3 ± 9.9 years; 55 men) were enrolled in the study. In the multiple linear regression analysis, after controlling for relevant clinical factors, MAP on admission (ipsilateral OR = 0.99 and contralateral OR = 0.99, both P < 0.005) was a significant independent predictor of bilateral gain. MAP > 105 mmHg on admission (OR = 0.77, P = 0.019) was significantly associated with ipsilateral gain. Diabetes mellitus was a significant predictive factor for bilateral gain (ipsilateral OR = 1.32 and contralateral OR = 1.22, both P < 0.005). No correlations were found between CA parameters and CSVD characteristics.

Conclusion

In SAO-related ischaemic stroke, patients with MAP > 105 mmHg on admission tended to have better ipsilateral CA. Diabetes mellitus appears to be an independent risk factor for CA impairment in patients with SAO-related stroke. CSVD may not be the main factor affecting bilateral CA in patients with SAO.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02854-4.

Low-Dimensional Metal-Halide Perovskites as High-Performance Materials for Memory Applications

Metal-halide perovskites have drawn profuse attention during the past decade, owing to their excellent electrical and optical properties, facile synthesis, efficient energy conversion, and so on. Meanwhile, the development of information storage technologies and digital communications has fueled the demand for novel semiconductor materials. Low-dimensional perovskites have offered a new force to propel the developments of the memory field due to the excellent physical and electrical properties associated with the reduced dimensionality. In this review, the mechanisms, properties, as well as stability and performance of low-dimensional perovskite memories, involving both molecular-level perovskites and structure-level nanostructures, are comprehensively reviewed. The property-performance correlation is discussed in-depth, aiming to present effective strategies for designing memory devices based on this new class of high-performance materials. Finally, the existing challenges and future opportunities are presented.

Small molecule-mediated rapid maturation of human induced pluripotent stem cell derived cardiomyocytes

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): Gravitation Program “Materials Driven Regeneration” by the Netherlands Organization for Scientific Research (RegmedXB #024.003.013) and the Marie Skłodowska-Curie Actions (Grant agreement RESCUE #801540). The EU-funded project BRAV3 (H2020, ID:874827)

Background

Human-induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iPSC-CMs) do not display all hallmarks of mature human primary cardiomyocytes: the ability to use fatty acids as an energy source, high mitochondrial mass, increased nuclei polyploidism, synchronized electrical conduction, and forceful contractions. Instead, their phenotype is similar to immature cardiomyocytes in the late fetal stage. This immaturity represents a bottleneck to their application in 1) disease modeling – as most cardiac (genetic) diseases have a middle-age onset – and 2) clinical use, where integration and functional coupling are key. So far, the mainly used methods to enhance iPSC-CM maturation include prolonged time-in-culture, 3D culture, cyclic mechanical stretch, and electrical stimulation with specialized media. However, these protocols are laborious, costly, and not easily scalable.

Methods

In this study, we developed a simple, low cost, and rapid protocol using two peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A/PGC-1α) activating small molecules: Asiatic Acid (AA) and GW501516 (GW) to promote cardiomyocyte maturity by inducing a metabolic switch to fatty acid utilization and increased mitochondrial biogenesis.

Results

Monolayers of iPSC-CMs were incubated with AA and GW every other day for 10 days resulting in increased expression of fatty acid-metabolism-related genes (5 and 10-fold increase in CPT1B gene expression, respectively), mitochondria biogenesis (protein expression of ATP5A) and fusion (50 and 100-fold increase in OPA1 gene expression, respectively). In addition, AA treated iPSC-CMs responded in the seahorse mitochondria stress test more rapidly to an artificial increase in mitochondrial activity and showed a higher flexibility in substrate utilization in the seahorse stress test. A more mature electrophysiological functionality was shown by increased ion channel gene expression (KCNA4, SCN5A, GJA1, CACNA1C, and SCN1B) and enhanced synchronous contraction in treated samples. Moreover, maturation was further shown by increased sarcomeric gene expression (5 and 7-fold increase in TNNI3 in AA and GW respectively) and nuclear polyploidism (&gt;4N fold 2.16 and 1.48-fold increase in AA and GW respectively).

Conclusions

Collectively, these findings show that AA and GW trigger a metabolic switch and induce extensive maturation of iPSC-CMs, providing a rapid and cost-effective method to obtain iPSC-CMs that more closely resemble their adult counterparts.

E2F7/8 is involved in cardiomyocyte polyploidy but does not affect myocardial reperfusion injury recovery

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): CSC fellowship

Background

Polyploidy cells consist of more than two complete sets of homologous chromosomes. Although a characteristic feature of cardiomyocytes and observed in all mammalian species, its molecular mechanism and biological functions are still unknown. Cardiomyocytes polyploidy in rodents occurs mainly through incomplete cytokinesis and increases with age. Studies have demonstrated that E2F7/8 transcription factors are key regulators of polyploidy in the liver and pancreas, however, it remains unclear if E2F7/8 control the generation of polyploidy cardiomyocytes and what the functional consequence is post-myocardial infarction (MI).

Methods

By using a tamoxifen inducible Cre/LoxP approach in new-born mice, we deleted E2F7/8 transcription factors ubiquitously and evaluated the biological significance of postnatal E2F7/8 loss. Mice underwent myocardial ischemia reperfusion injury (IRI) and heart function was assessed by 4D-echocardiography. Cardiomyocyte nucleus polyploidy was measured by FACS and microscope.

Results

Deficiency of E2F7/8 significantly suppress cardiomyocyte mononucleated and multinucleated polyploidy, as well as dramatically decreased hepatocytes polyploidy. E2F7/8 defect also led to a decrease in cardiac stress related marker lever such as ANP, BNP, MMP2, β-MHC/α-MHC and an increase in CD31 expression level. Surprisingly, E2F7/8 deletion did not have impact on cardiac function and dimensions post-IRI.

Conclusion

In summary, we identified that E2F7/8 activity is involved in the cellular polyploidy in the heart but did not affect myocardial function after myocardial injury.

Myocardial tissue slices for modeling of the human PLN p.Arg14del associated cardiomyopathy

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NWO - The Dutch Research Council

Background

Current in vivo preclinical models lack the predictability of the clinical efficacy resulting in a high dropout rate of therapeutic candidates. Advanced human-based models are required to bridge this gap and indicate the potential of novel therapeutic approaches[1].  Myocardial tissue slices are an in vitro model that recapitulates the native multicellular architecture of the heart. This allows for modeling cellular processes in a macroscopic context entailing great promise. The most common cardiomyopathy-related mutation in the Netherlands is the loss of arginine at position 14 (p.Arg14del) in the phospholamban protein (PLN). PLN is a critical regulator of calcium cycling and contractility in the heart. The p.Arg14del mutation results in a super inhibition of SERCA2a and thus aberrant calcium handling and reduced contractile force. Mice models harbouring the PLN p.Arg14del do not completely recapitulate the human manifestation mainly due to the difference between species; heart rate, Calcium-cycling and ion properties, and different myosin heavy chain isoforms, showing the unmet need for a human-based model[2,3].

Methods & Results

300 µm thick viable myocardial tissue were sectioned from a PLN p.Arg14del patient’s left ventricle. Although the myocardial tissue slices were kept alive for eight days in static culture, these conditions initiated cell death and dedifferentiation. The tissue slices show the greatest resemblance to the intact architecture of the in vivo human heart, it is the most relevant model for viral transduction in the human heart, and proof-of-principle of this is performed. Myocardial tissue slices of a PLN p.Arg14del patient retain the structural phenotype shown by the fibrofatty deposition. Similarly, functional patient characteristics, aberrant calcium handling, and reduced contractile force are preserved.

Conclusion

Myocardial tissue slices recapitulate the (patho)physiology of the heart, as shown here with the PLN p.Arg14del case. However, the static culture conditions induce remodeling of the heart and thus only allow for acute measures in the native heart. To prolong the period that the slices recapitulate the native heart, culture conditions should mimic the environment of the heart. The tissue slices allow for a currently unmet need to modulate the complex architecture of the human heart with e.g. novel delivery tools or therapeutic interventions. All in all, myocardial tissue slices are a promising model that can give novel insights into the physiology of the human heart, and therapeutic intervention on induced or genetic cardiomyopathies.

Ordered Mesoporous Boron Carbon Nitrides with Tunable Mesopore Nanoarchitectonics for Energy Storage and CO2 Adsorption Properties

Porous boron carbon nitride (BCN) is one of the exciting systems with unique electrochemical and adsorption properties. However, the synthesis of low-cost and porous BCN with tunable porosity is challenging, limiting its full potential in a variety of applications. Herein, the preparation of well-defined mesoporous boron carbon nitride (MBCN) with high specific surface area, tunable pores, and nitrogen contents is demonstrated through a simple integration of chemical polymerization of readily available sucrose and borane ammonia complex (BAC) through the nano-hard-templating approach. The bimodal pores are introduced in MBCN by controlling the self-organization of BAC and sucrose molecules within the nanochannels of the template. It is found that the optimized sample shows a high specific capacitance (296 F g^-1 at 0.5 A g^-1 ), large specific capacity for sodium-ion battery (349 mAg h^-1 at 50 mAh g^-1 ), and excellent CO₂ adsorption capacity (27.14 mmol g^-1 at 30 bar). Density functional theory calculations demonstrate that different adsorption sites (BC, BN, CN, and CC) and the large specific surface area strongly support the high adsorption capacity. This finding offers an innovative breakthrough in the design and development of MBCN nanostructures for energy storage and carbon capture applications.

MicroRNA-214-3p Ameliorates LPS-Induced Cardiomyocyte Injury by Inhibiting Cathepsin B

Myocardial injury is a common complication of sepsis. MicroRNA (miRNA) miR-214-3p is protective against myocardial injury caused by sepsis, but its mechanism in lipopolysaccharide (LPS)- induced cardiomyocyte injury is still unclear. An AC16 cell injury model was induced by LPS treatment. Cell Counting Kit-8 and flow cytometry assay showed decreased cell viability and increased apoptosis in LPS-treated AC16 cells. The levels of caspase- 3, Bax, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), myosin 6 (Myh6), myosin 7 (Myh7), reactive oxygen species (ROS), and malondialdehyde (MDA) were increased in LPS-treated AC16 cells, but the levels of Bcl-2 and superoxide dismutase (SOD) were decreased. MiR-214-3p was down-regulated and cathepsin B (CTSB) was upregulated in LPS-treated AC16 cells. At the same time, miR-214-3p could target CTSB and reduce its expression. We also found that a miR-214-3p mimic or CTSB silencing could significantly reduce LPSinduced apoptosis, decrease ROS, MDA, caspase-3, and Bax and increase SOD and Bcl-2. CTSB silencing could significantly reduce ANP, BNP, Myh6, and Myh7 in LPS-treated AC16 cells. The effects of CTSB silencing were reversed by a miR-214-3p inhibitor. In summary, miR-214-3p could inhibit LPSinduced myocardial injury by targeting CTSB, which provides a new idea for myocardial damage caused by sepsis.

Onset of inverse magnetic energy transfer in collisionless turbulent plasmas

Inverse magnetic energy transfer from small to large scales is a key physical process for the origin of large-scale strong magnetic fields in the universe. However, so far, from the magnetohydrodynamic perspective, the onset of inverse transfer is still not fully understood, especially the underlying dynamics. Here, we use both two-dimensional and three-dimensional particle-in-cell simulations to show the self-consistent dynamics of inverse transfer in collisionless decaying turbulent plasmas. Using the space filtering technique in theory and numerical analyses, we identify magnetic reconnection as the onset and fundamental drive for inverse transfer, where, specifically, the subscale electromotive force driven by magnetic reconnection do work on the large-scale magnetic field, resulting in energy transfer from small to large scales. The mechanism is also verified by the strong correlations in locations and characteristic scales between inverse transfer and magnetic reconnection.

Multi-Site Infant Brain Segmentation Algorithms: The iSeg-2019 Challenge

To better understand early brain development in health and disorder, it is critical to accurately segment infant brain magnetic resonance (MR) images into white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF). Deep learning-based methods have achieved state-of-the-art performance; h owever, one of the major limitations is that the learning-based methods may suffer from the multi-site issue, that is, the models trained on a dataset from one site may not be applicable to the datasets acquired from other sites with different imaging protocols/scanners. To promote methodological development in the community, the iSeg-2019 challenge (http://iseg2019.web.unc.edu) provides a set of 6-month infant subjects from multiple sites with different protocols/scanners for the participating methods. T raining/validation subjects are from UNC (MAP) and testing subjects are from UNC/UMN (BCP), Stanford University, and Emory University. By the time of writing, there are 30 automatic segmentation methods participated in the iSeg-2019. In this article, 8 top-ranked methods were reviewed by detailing their pipelines/implementations, presenting experimental results, and evaluating performance across different sites in terms of whole brain, regions of interest, and gyral landmark curves. We further pointed out their limitations and possible directions for addressing the multi-site issue. We find that multi-site consistency is still an open issue. We hope that the multi-site dataset in the iSeg-2019 and this review article will attract more researchers to address the challenging and critical multi-site issue in practice.

Downregulated long noncoding RNA LUCAT1 inhibited proliferation and promoted apoptosis of cardiomyocyte via miR-612/HOXA13 pathway in chronic heart failure

OBJECTIVE

Long non-coding RNAs (lncRNAs) have been reported to play important roles in numerous kinds of cardiovascular disease, including chronic heart failure (CHF). In this study, we mainly focused on investigating the potential roles of lncRNA LUCAT1 patients with CHF.

PATIENTS AND METHODS

RT-PCR was used to detect the expressions of LUCAT1 and miR-612 in serum samples of CHF patients (n=60) and healthy volunteers. Relationships between the expressions of LUCAT1 and miR-612, LUCAT1 and overall survival (OS) were analyzed using the Kaplan-Meier method. Si-LUCAT1 and miR-612 mimic were constructed and respectively transfected into AC16 cells to explore the functions of LUCAT1 and miR-612. Cell proliferation abilities were detected by CCK-8 assay AC16 cells. Cell apoptotic rates were measured by flow cytometry (FACS) analysis. Western blot (WB) was performed to detect the protein levels of HOXA13, Bcl-2, Bax, Bad and Cleaved Caspase3. In addition, luciferase gene reporter assay was used to prove the relationships between LUCAT1 and miR-612, miR-612 and HOXA13.

RESULTS

Firstly, we found that LUCAT1 was decreased for 1.7 folds in CHF patients, which was correlated with poor prognosis patients. LUCAT1 repression inhibited cell proliferation and promoted cell apoptosis in human cardiomyocyte cell line AC16 cells. Furthermore, we found that miR-612 was increased for 2.0 folds in CHF patients, which was negatively interacted with LUCAT1 expression. Luciferase gene reporter assay demonstrated that LUCAT1 could directly bind with miR-612 in AC16 cells. Moreover, miR-612 overexpression also inhibited cell proliferation and promoted cell apoptosis in AC16 cells. Luciferase reporter assay indicated that miR-612 could directly target at HOXA13 in AC16 cells, which was associated with cell proliferation and apoptosis. Finally, miR-612 inhibitor was transfected into AC16 cells with si-LUCAT1. The results showed that the inhibited cell proliferation and promoted cell apoptosis were reversed, which confirmed that LUCAT1 repression inhibited cell proliferation and promoted apoptosis via miR-612/HOXA13 axis in CHF patients.

CONCLUSIONS

According to the above results, our study revealed that LUCAT1 was decreased in CHF patients, which was correlated with poor prognosis of CHF patients. Furthermore, the downregulation of LUCAT1 inhibited cell proliferation and promoted cell apoptosis via targeting miR-612/HOXA13 axis. Our results elucidated a potential mechanism underlying cardiomyocyte apoptosis, which might be used as a promising prognostic marker and a potential target for CHF patients.

Structure and thermal properties of beeswax-based oleogels with different types of vegetable oil

Beeswax-based oleogels with different types of vegetable oil, including camellia oil (CO), soybean oil (SO), sunflower oil (SFO), or flaxseed oil (FO), were prepared and their structure and thermal properties were evaluated. The critical concentration of oleogel obtained from each of CO, SO, and SFO at 25 °C was 3% (w/w), and that from FO was 4%. Thermal measurements revealed similar thermodynamic curves for oleogels in different lipid phases. X-Ray diffraction showed orthorhombic perpendicular subcell packing and characteristic peaks of the β’ form. Furthermore, a morphology analysis of the crystals showed that they were needle shaped. Fourier transform-infrared spectra revealed that beeswax-based oleogels were formed via non-covalent bonds and may be stabilized with physical entanglements. The oleogels showed oil type-dependent oxidative abilities, but they were all stable and showed no obvious changes in peroxide value during 90 days of storage at 5 °C.

Smoking Status Affects the Association Between Hematoma Heterogeneity and Hematoma Expansion

Objective

The purpose of this study was to verify the relationship between hematoma heterogeneity and hematoma expansion and explore any effect modifiers through subgroup analyses.

Methods

Clinical records of 357 patients with spontaneous cerebral hemorrhage at Shenzhen Second People’s Hospital from March 2016 to October 2018 were included in the study. Hematoma heterogeneity was measured on the first noncontrast computed tomography image according to the Barras scale. Hematoma expansion was defined as an absolute hematoma volume increase of 6 mL, or a 33% increase. We performed univariate and multivariate logistic regression analyses, as well as subgroup analyses, to assess the relationship between the presence of heterogeneity on noncontrast computed tomography and hematoma expansion.

Results

Hematoma expansion occurred in 79 (22.13%) of the 357 patients with intracerebral hemorrhage (ICH). Among the patients with ICH, there were 83 smokers, accounting for 23.24%. The average patient age was 56.21 ± 13.75 years, and 74.51% were male. Compared with the absence of heterogeneity, the risk of hematoma expansion increased by 1.06 times (odds ratio, 2.06; 95% confidence interval, 1.10–3.86). Based on the subgroup analysis, smoking status was found to modify the association between heterogeneity and hematoma expansion; the association was stronger in smokers than in nonsmokers (odds ratio, 10.23; 95% confidence interval, 2.15–48.65).

Conclusions

Heterogeneity independently predicts hematoma expansion, especially in smoking patients.

Prognostic nomogram for patients with minor stroke and transient ischaemic attack

BACKGROUND

Ischaemic stroke and transient ischaemic attack (TIA) share a common cause. We aim to develop and validate a concise prognostic nomogram for patients with minor stroke and TIA.

METHODS

A total of 994 patients with minor stroke and TIA were included. They were split into a derivation (n=746) and validation (n=248) cohort. The modified Rankin Scale (mRS) scores 3 months after onset were used to assess the prognosis as unfavourable outcome (mRS≥2) or favourable outcome (mRS<2).

RESULT

The final model included seven independent predictors: gender, age, baseline National Institute of Health Stroke Scale (NIHSS), hypertension, diabetes mellitus, white blood cell and serum uric acid. The Harrell's concordance index (C-index) of the nomogram for predicting the outcome was 0.775 (95% CI 0.735 to 0.814), which was confirmed by the validation cohort (C-index=0.787 (95% CI 0.722 to 0.853)). The calibration curve showed that the nomogram-based predictions were consistent with actual observation in both derivation cohort and validation cohort.

CONCLUSION

The proposed nomogram showed favourable predictive accuracy for minor stroke and TIA. This has the potential to contribute to clinical decision-making.

Oscillatory surface deformation of paramagnetic rare-earth solutions driven by an inhomogeneous magnetic field

The deformation of the free surface of a paramagnetic liquid subjected to a nonuniform magnetic field is studied. A transient deformation of the surface caused by the interplay of gravity, magnetic field, and surface tension is observed when a permanent magnet is moved vertically downward to the free surface of the liquid. Different concentrations of rare-earth-metal salt (DyCl_{3}) are used and different magnet velocities are studied. The deformation of the interface is followed optically by means of a microscope and recorded with a high-speed camera. The experimental results are compared and discussed with complementary numerical simulations. Detailed results are given for the static shape of the deformed surface and the temporal evolution of the surface deformation below the center of the magnet. The frequency of the surface oscillations is found to depend on the concentration of the salt and is compared with analytical findings. Finally, a potential application of the effects observed is presented.

Improvement of gibberellin production by a newly isolated Fusarium fujikuroi mutant

AIMS

To obtain and investigate the potential mechanism for GA₃ production in Fusarium fujikuroi GA-251, a high GA₃ producer.

METHODS AND RESULTS

Fusarium fujikuroi IMI 58289 was bred with Cobalt-60 (⁶⁰ Co) radiation and lithium chloride treatment. The best mutant strain GA-251 was obtained for the subsequent optimization of fermentation conditions. The yield of GA₃ by GA-251 was 2100 mg l^-1 , while the wild-type strain was 100 mg l^-1 , which is a 21-fold increase in the yield. To elucidate the mechanism of high GA₃ yield of GA-251, the genome was sequenced and compared with wild-type strain IMI 58289. The results showed 2295 single nucleotide polymorphisms, 1242 small indels and 30 structural variants. These mutations were analysed and enriched in the MAPK signalling pathway, the mRNA surveillance pathway and endocytosis. The potential reasons for the improved GA₃ biosynthesis were investigated.

CONCLUSIONS

The potential mechanism of high GA₃ yield was attributed to endocytosis pathway and histone modification proteins family.

SIGNIFICANCE AND IMPACT OF THE STUDY

A mutant strain GA-251 in this work that could potentially be utilized in the industrial yield of GA₃ . The comparative genome analysis would shed light onto the mechanism of yield improvement and be a theoretical guide for further metabolic engineering.

Assessing the risk of ASFV entry into Japan through pork products illegally brought in by air passengers from China and fed to pigs in Japan

A risk assessment was conducted to assess the risk of ASFV entry into Japan through pork products illegally brought in by air passengers from China and fed to pigs in Japan. Scenario tree modelling was used with the following entry and exposure pathway considered to be the most likely route of ASF entry: an ASFV infected pork product is illegally brought into Japan by air travellers from China; this pork product is then used in a restaurant where scrap waste is recycled for animal feed and subsequently fed to pigs without being heat-treated. Input parameter values were based on surveys conducted by the authors, scientific data gathered from the literature and official data published by government agencies. The annual probability of ASFV entry into Japan via this pathway was predicted to be 0.20 (90% prediction interval: 0.00-0.90). The wide prediction interval was mainly caused by the uncertainty regarding the dose response relation of ASFV, followed by the probability of an ASF infected pig dying on affected farms, the loading of ASFV in an infected pig and the probability of an illegally imported pork product being heat-treated in China and used in restaurants. The results of scenario analysis revealed that the annual probability of ASFV entry into Japan will increase with an increase in the number of ASF affected farms in China. The probability of ASFV entry will increase substantially even if only a small proportion of Ecofeed is not heat-treated during the production process. The probability will decrease if an increased proportion of farms that feed swill apply heat-treatment before feeding swill to their pigs. These findings indicate that stringent application of heat-treatment of Ecofeed and swill is key to protecting the Japanese pig industry from the introduction of ASFV.

Identification and Clinical Analysis of the First Nonsense Mutation in the PSEN1 Gene in a Family With Acute Encephalopathy and Retinitis Pigmentosa

In the present study, we investigated the genetic variation in a family with acute encephalopathy and retinitis pigmentosa. Nine of 25 people in this family underwent genetic testing. Three family members, namely, the proband and the proband's two sisters, showed symptoms resembling those of meningoencephalitis and simultaneously suffered from retinitis pigmentosa. Whole-exome sequencing and Sanger sequencing identified a heterozygous mutation, chr14: 73673106 c.881G>A (p.W294^*), in the presenilin 1 (PSEN1) gene in these three family members, and the SWISS-MODEL server predicted the formation of a truncated protein. This mutation was not found in the asymptomatic family members. This mutation is a newly discovered nonsense mutation that results in a truncated protein. Although the current genetic evidences may indicate the likelihood of association, further investigations are needed to establish the genotype and phenotype relationship.

Antimicrobial usage on 72 farrow-to-finish pig farms in Japan from 2015 to 2017

In Japan veterinary antimicrobials are used most in the pig production sector. However, there is a paucity of data on the quantity of antimicrobials used on pig farms in Japan. This study describes antimicrobial use on Japanese pig farms in 2015, 2016 and 2017 in terms of mg of active ingredient per kg of PCU (population correction unit). Data on antimicrobial use from a total of 72 farrow-to finish farms over these three years were used in the study. The results revealed that the average use of antimicrobials in 2015, 2016 and 2017 was 304.8 (SD = 226.3), 311.2 (SD = 241.0) and 342.9 (SD = 291.3) mg/kg PCU, respectively. Most (97%) of the antimicrobials were administered orally. The most commonly used antimicrobials were tetracyclines, followed by macrolides, penicillins and sulfonamides. Tohoku was the region in which the lowest quantities of antimicrobial were used whilst South Kanto was the region in which the largest amount was used. The use of antimicrobials was on the increase in the North Kanto, South Kanto and Kyushu regions.

Shenzhen stroke emergency map improves access to rt-PA for patients with acute ischaemic stroke

Prehospital delay is one of the major causes of low rate of intravenous recombinant tissue plasminogen activator (rt-PA) thrombolysis for acute ischaemic stroke in China. Regional emergency systems have been proven a successful approach to improve access to thrombolysis. Shenzhen is a high population density city with great geographical disparity of healthcare resources, leading to limited access to rt-PA thrombolysis for most patients with acute ischaemic stroke. To improve rapid access to rt-PA thrombolysis in Shenzhen, a Shenzhen stroke emergency map was implemented by Shenzhen healthcare administrations. This map comprised certification of qualified local hospitals, identification of patients with stroke, acute stroke transport protocol and maintenance of the map. We conducted a retrospective observational study to compare consecutive patients with acute stroke arriving at qualified local hospitals before and after implementation of the Shenzhen stroke emergency map. After implementation of the map, the rate of patients receiving rt-PA thrombolysis increased from 8.3% to 9.7% (p=0.003), and the rate of patients treated with endovascular thrombectomy increased from 0.9% to 1.6% (p<0.001). Sixteen of 20 hospitals have an increase in the number of patients with stroke treated with rt-PA thrombolysis. The median time between receipt of the call and arrival on the scene reduced significantly (17.0 min vs 9.0 min, p<0.001). In Shenzhen Second People's Hospital, the median onset-to-needle time and door-to-needle time were reduced (175.5 min vs 149.5 min, p=0.039; 71.5 min vs 51.5 min, p<0.001). No statistically significant differences were found in the proportion of rt-PA-treated patients within various geographical distances. Currently, there are more than 40 cities in China implementing a stroke emergency map. The Shenzhen stroke emergency map improves access to rt-PA thrombolysis for acute ischaemic stroke, and the novel model has been expanded to multiple areas in China. Future efforts should be conducted to optimise the stroke emergency map.

Fast-tracking acute stroke care in China: Shenzhen Stroke Emergency Map

China has the largest stroke population and at-risk population in the world. However, it has a lower thrombolytic therapy rate and longer onset-to-needle time/door-to-needle time for patients who had an acute stroke compared with developed countries, which might be due to redundant procedures or inefficient systems. Things are changing due to some new initiatives. Two years ago, a new emergency system in China, Stroke Emergency Map, was first launched as a regional emergency system in Shenzhen, the bustling metropolis just north of Hong Kong. As a result of the Stroke Emergency Map in Shenzhen, the number of thrombolytic cases increased in the last 2 years, from 568 to 809 annually. The Stroke Emergency Map, first pioneered in Shenzhen and now spreading to the rest of China, is a comprehensive and interdisciplinary system. The benefits are not just the immediate improvements in the acute stroke care because the continuous data collection and audit allows for improvements in logistics and future strategies.

Lp-PLA2 as a risk factor of early neurological deterioration in acute ischemic stroke with TOAST type of large arterial atherosclerosis

Introduction: Lipoprotein-associated phospholipase A₂ (Lp-PLA₂) is a well-known risk factor of atherosclerotic vascular diseases. Nevertheless, its role in the acute phase of ischemic stroke is still unclear. The aim of this study is to identify the relationship between Lp-PLA₂ levels and early neurological deterioration (END) in acute ischemic stroke patients with Trial of Org 10 172 in Acute Stroke Treatment (TOAST) subtype of large arterial atherosclerosis (LAA). Methods: We enrolled Chinese patients with first ever acute ischemic stroke admitted to Neurology Department of Shenzhen Second People's Hospital within 48 h from onset of symptoms during January - November 2015. Demographic and laboratory information were collected while END was defined as an increase in the National Institute of Health Stroke Scale score by ≥ 1 point in motor power, or ≥ 2 points in the total score within 10 days after admission. Results: Overall 181 patients were involved; END was diagnosed in 30 patients within 10 days after admission. The odds ratio for END increased with increasing levels of Lp-PLA₂ (intermediate level, OR = 1.96, 95%CI 1.02-4.27, p = 0.041; high level, OR = 2.99, 95%CI 1.26-5.73, p = 0.023). Conclution: Intermediate and high level of Lp-PLA₂ was identified as independent predictor of END in multivariate analysis. Lp-PLA₂ could be valued as a risk factor of END in patients with acute ischemic stroke with TOAST subtype of LAA.

Aspartate β-hydroxylase disrupts mitochondrial DNA stability and function in hepatocellular carcinoma

The mechanism of aberrant mitochondrial genome and function in hepatocellular carcinoma (HCC) remains largely unknown. Our previous study demonstrated an increased expression of aspartate β-hydroxylase (ASPH) in HCC tissues, which was associated with tumor invasiveness and a worse prognosis. Currently, we unexpectedly observed the presence of ASPH in purified mitochondrial protein fraction. In addition, immunostaining of both exogenously and endogenously expressed ASPH showed a colocalization with mitochondrial biomarkers. This study aimed to investigate whether the mitochondrial ASPH is involved in mitochondrial malfunction in HCC. Our results showed that ASPH overexpression in HCC tissues was correlated with decreased copy numbers of displacement loop (D-loop) and NADH dehydrogenase subunit 1 (ND-1) and enhanced D-loop mutation, suggesting the disrupted mitochondrial DNA (mtDNA) stability. The reduced mtDNA copy numbers were associated with aggressive clinicopathological features of HCC. The loss of mtDNA integrity induced by enforced expression of ASPH was accompanied with mitochondrial dysfunction, which was characterized by the aberrant mitochondrial membrane potential, decreased ATP generation and enhanced reactive oxygen species. In contrast, knocking down ASPH by siRNA in HCC cell lines showed the opposite impact on mtDNA integrity and function. Mass spectrometry and co-immunoprecipitation further identified that ASPH interacted with histone H2A member X (H2AX). ASPH overexpression diminished the interaction between H2AX and mitochondrial transcription factor A (mtTFA), an important DNA-binding protein for mtDNA replication, which then reduced the binding of mtTFA to D-loop region. Collectively, our results demonstrate that ASPH overexpression disrupts the mtDNA integrity through H2AX-mtTFA signal, thereby affecting mitochondrial functions in HCC.

Preparation and evaluation of cefquinome-loaded gelatin microspheres and the pharmacokinetics in pigs

Cefquinome (CEF) is widely used for veterinary clinical applications because of its broad spectrum and high efficiency. However, frequent administrations are required due to its short elimination half-life. In this study, cefquinome sulfate gelatin microspheres (CEF-GMS) were prepared as a sustained-release formulation using emulsion chemical cross-linking technique. Physical properties, stability, sustained-release property in vitro, and pharmacokinetics in pigs were assessed. The morphology of CEF-GMS showed a good sphericity with porous structure on the surface, and the mean diameter was 8.80 ± 0.78 μm, with 90.60 ± 3.98% of the total in the range of 5-20 μm. There were no significant changes of all estimated indexes in the stability tests. In vitro drug release study showed that the release of CEF from CEF-GMS was much slower than that from crude CEF in a release medium. Pharmacokinetic characteristics were evaluated following intramuscular administration of CEF-GMS or Cefquinome sulfate injection (CEF-Inj) in pigs at a dosage of 4 mg CEF/kg body weight. The plasma drug concentration-time data of CEF-GMS and CEF-Inj were both best fitted by two-compartment models with first-order absorption, and the elimination half-life of CEF-GMS was almost 10 times that of CEF-Inj. Overall, CEF-GMS might be used as a sustained-release formulation of CEF for veterinary clinical applications.

Patients with HBV-related acute-on-chronic liver failure have increased concentrations of extracellular histones aggravating cellular damage and systemic inflammation

Acute-on-chronic liver failure (ACLF) is the most common type of liver failure and associated with grave consequences. Systemic inflammation has been linked to its pathogenesis and outcome, but the identifiable triggers are absent. Recently, extracellular histones, especially H4, have been recognized as important mediators of cell damage in various inflammatory conditions. This study aimed to investigate whether extracellular histones have clinical implications in patients with hepatitis B virus (HBV)-related ACLF. One hundred and twelve patients with HBV-related ACLF, 90 patients with chronic hepatitis B, 88 patients with HBV-related liver cirrhosis and 40 healthy volunteers were entered into this study. Plasma histone H4 levels, cytokine profile and clinical data were obtained. Besides, patient's sera were incubated overnight with human L02 hepatocytes or monocytic U937 cells in the presence or absence of antihistone H4 antibody, and cellular damage and cytokine production were evaluated. We found that plasma histone H4 levels were greatly increased in patients with ACLF as compared with chronic hepatitis B, liver cirrhosis and healthy control subjects and were significantly associated with disease severity, systemic inflammation and outcome. Notably, ACLF patients' sera incubation decreased cultured L02 cell integrity and induced profound cytokine production in the supernatant of U937 cells. Antihistone H4 antibody treatment abrogated these adverse effects, thus confirming a cause-effect relationship between extracellular histones and organ injury/dysfunction. The data support the hypothesis that the increased extracellular histone levels in ACLF patients may aggravate disease severity by inducing cellular injury and systemic inflammation. Histone-targeted therapies may have potentially interventional value in clinical practice.

Construction and identification of a model for HJURP gene defect expression in human embryo villus cells

OBJECTIVES

To construct a lentiviral vector for RNA interference (RNAi) of the HJURP gene and to identify the silencing efficiency in the human embryo villus cells and to provide a human embryo villus cells multiplication and chromosome segregation.

MATERIALS AND METHODS

In accordance with the study, three specific sequences of siRNA targeting HJURP gene were designed, synthesized, then the complementary DNA containing both sense and antisense oligonucleotides of the targeting sequences were annealed and inserted into the lentiviral vector.The correct clonings were confirmed by PCR and sequencing. The most effective recombinant lentivirus vector was screened, and the recombinant plasmids with the lentivirus packaging mixes were co-transfected into 293T cells to obtain packaged lentivirus particles. Then viral titer was determined. The silencing efficiency of target gene in human embryo villus cells was detected by Real-Time PCR.

RESULTS

DNA sequencing showed that the shRNA sequence was successfully inserted into the lentivirus vector. The recombinant lentiviral vector was successfully transfected into 293T cells. The recombinant lentivirus had a titer of 108 PFU/ml. After silencing HJURP gene in human embryo villus cells, the expression level of HJURP mRNA decreased significantly and the RNAi efficiency was greater than 70%.

CONCLUSION

A lentiviral shRNA expression vector targeting the HJURP gene was successfully constructed and may effectively silence the target gene at a cellular level, which provides a experimental model for the influence of HJURP gene expressing inhibition on human embryo villus cells multiplication and chromosome segregation.

Understanding hydraulic fracturing: a multi-scale problem

Despite the impact that hydraulic fracturing has had on the energy sector, the physical mechanisms that control its efficiency and environmental impacts remain poorly understood in part because the length scales involved range from nanometres to kilometres. We characterize flow and transport in shale formations across and between these scales using integrated computational, theoretical and experimental efforts/methods. At the field scale, we use discrete fracture network modelling to simulate production of a hydraulically fractured well from a fracture network that is based on the site characterization of a shale gas reservoir. At the core scale, we use triaxial fracture experiments and a finite-discrete element model to study dynamic fracture/crack propagation in low permeability shale. We use lattice Boltzmann pore-scale simulations and microfluidic experiments in both synthetic and shale rock micromodels to study pore-scale flow and transport phenomena, including multi-phase flow and fluids mixing. A mechanistic description and integration of these multiple scales is required for accurate predictions of production and the eventual optimization of hydrocarbon extraction from unconventional reservoirs. Finally, we discuss the potential of CO2 as an alternative working fluid, both in fracturing and re-stimulating activities, beyond its environmental advantages.This article is part of the themed issue 'Energy and the subsurface'.

Nationwide Distribution of Bovine Influenza D Virus Infection in Japan

Cattle are major reservoirs of the provisionally named influenza D virus, which is potentially involved in the bovine respiratory disease complex. Here, we conducted a serological survey for the influenza D virus in Japan, using archived bovine serum samples collected during 2010–2016 from several herds of apparently healthy cattle in various regions of the country. We found sero-positive cattle across all years and in all the prefectural regions tested, with a total positivity rate of 30.5%, although the positivity rates varied among regions (13.5–50.0%). There was no significant difference in positivity rates for Holstein and Japanese Black cattle. Positivity rates tended to increase with cattle age. The herds were clearly divided into two groups: those with a high positive rate and those with a low (or no) positive rate, indicating that horizontal transmission of the virus occurs readily within a herd. These data demonstrate that bovine influenza D viruses have been in circulation for at least 5 years countrywide, emphasizing its ubiquitous distribution in the cattle population of Japan.