The single-cell stereo-seq reveals region-specific cell subtypes and transcriptome profiling in Arabidopsis leaves

Understanding the complex functions of plant leaves requires a thorough characterization of discrete cell features. Although single-cell gene expression profiling technologies have been developed, their application in characterizing cell subtypes has not been achieved yet. Here, we present scStereo-seq (single-cell spatial enhanced resolution omics sequencing) that enabled us to show the bona fide single-cell spatial transcriptome profiles of Arabidopsis leaves. Subtle but significant transcriptomic differences between upper and lower epidermal cells have been successfully distinguished. Furthermore, we discovered cell-type-specific gene expression gradients from the main vein to the leaf edge, which led to the finding of distinct spatial developmental trajectories of vascular cells and guard cells. Our study showcases the importance of physical locations of individual cells for exerting complex biological functions in plants and demonstrates that scStereo-seq is a powerful tool to integrate single-cell location and transcriptome information for plant biology study.

Real-Time Semantic Segmentation via Spatial-Detail Guided Context Propagation

Nowadays, vision-based computing tasks play an important role in various real-world applications. However, many vision computing tasks, e.g., semantic segmentation, are usually computationally expensive, posing a challenge to the computing systems that are resource-constrained but require fast response speed. Therefore, it is valuable to develop accurate and real-time vision processing models that only require limited computational resources. To this end, we propose the spatial-detail guided context propagation network (SGCPNet) for achieving real-time semantic segmentation. In SGCPNet, we propose the strategy of spatial-detail guided context propagation. It uses the spatial details of shallow layers to guide the propagation of the low-resolution global contexts, in which the lost spatial information can be effectively reconstructed. In this way, the need for maintaining high-resolution features along the network is freed, therefore largely improving the model efficiency. On the other hand, due to the effective reconstruction of spatial details, the segmentation accuracy can be still preserved. In the experiments, we validate the effectiveness and efficiency of the proposed SGCPNet model. On the Cityscapes dataset, for example, our SGCPNet achieves 69.5% mIoU segmentation accuracy, while its speed reaches 178.5 FPS on 768 x 1536 images on a GeForce GTX 1080 Ti GPU card. In addition, SGCPNet is very lightweight and only contains 0.61 M parameters. The code will be released at https://github.com/zhouyuan888888/SGCPNet.

[Application of bionics in spinal surgery]

Spinal bionic therapy is the application of bionics concept, by imitating the natural anatomical structure and physiological function of the spine, to treat spinal diseases using various modern technology, materials and equipment .How to repair or preserve the anatomical structure and function of spine to the maximum extent while treating spinal diseases is an important content of spinal bionic therapy.Firstly, the use of movable spinal implants not only preserves the spinal mobility function to a certain extent, reduces the degeneration of adjacent segments, but also reduces the incidence of internal fixation fracture and improves the long-term efficacy.Secondly, with the help of the development of three dimensional printing technology, personalized artificial prostheses can be made to fill the spinal structure with complex defects, and biological scaffolds and functional prostheses with anti-tumor drugs can not only realize the biomimetic and functional spine anatomy, but also become a multiplier of the efficacy of anti-tumor drugs.Thirdly, in the design and manufacture of spinal orthopaedic braces, computer aided design and manufacturing technology can make spinal orthopaedic braces more comfortable with better orthopaedic effect and ergonomic characteristics.How to apply bionics concepts and relate technologies to spinal surgery have not been determined yet, and no relevant diagnosis and treatment guidelines have been formulated.It is foreseeable that with the continuous development of medical technology, the content of spinal bionic therapy will be gradually enriched and improved, and become a powerful measure to overcome difficulties in the diagnosis and treatment of spinal surgery diseases.

BiTE secretion from in situ-programmed myeloid cells results in tumor-retained pharmacology

Bispecific T-Cell Engagers (BiTEs) are effective at inducing remission in hematologic cancers, but their use in solid tumors has been challenging due to their extreme potency and on-target, off-tumor toxicities in healthy tissue. Their deployment against solid tumors is further complicated by insufficient drug penetration, a hostile tumor microenvironment, and immune escape. To address these challenges, we developed targeted nanocarriers that can deliver in vitro-transcribed mRNA encoding BiTEs to host myeloid cells – a cell type that is actively recruited into the tumor microenvironment. We demonstrate in an immunocompetent mouse model of ovarian cancer, that infusion of these nanoparticles directs BiTE expression to tumor sites, which reshapes the microenvironment from suppressive to permissive and triggers disease regression without systemic toxicity. In contrast, conventional injections of recombinant BiTE protein at doses required to achieve anti-tumor activity, induced systemic inflammatory responses and severe tissue damage in all treated animals. Implemented in the clinic, this in situ gene therapy could enable physicians – with a single therapeutic – to safely target tumor antigen that would otherwise not be druggable due to the risks of on-target toxicity and, at the same time, reset the tumor milieu to boost key mediators of antitumor immune responses.

[Analysis of the factors influencing the elimination strategies with the current status of diagnosis and treatment of hepatitis C in hospital]

Objective: To understand the current status of screening, diagnosis, and treatment and analyze the factors influencing micro-elimination strategy, so as to achieve hepatitis C elimination in hospital. Methods: Anti-HCV and HCV RNA test results of patients from October 2017 to September 2020 were retrospectively analyzed. Anti-HCV positive rates and factors influencing different genders, ages, places of residence and departments were analyzed. After comparing anti-HCV-positive patients with HCV RNA-positive patients with duplicate entries in "Name" and "Date of birth", the data were divided into three categories: anti-HCV positive without HCV RNA test, HCV RNA positive in single test, and HCV RNA positive many times in multiple tests. The above three types of patients were followed-up by telephone. According to the hospital follow-up results, current status of diagnosis and treatment and the factors influencing the micro-elimination strategy of hepatitis C were studied and analyzed. The comparison of data between groups were performed using χ(2) or χ(2) continuity-correction test. Results: Anti-HCV positive detection rate was 1.34% (899/66 866). The positive rate of male patients aged 40 and over residing in cities was significantly higher than female patients under 40 years old residing in rural areas, and the difference was statistically significant (χ(2) = 55.178, 264.11, 36, 351, P < 0.05). There were 90 (10.02%) and 809 cases (89.98%) in outpatient and inpatient departments, respectively, with no statistically significant difference between the two (χ(2) = 0.002, P > 0.05). The total number of anti-HCV positive cases were 196 in Gastroenterology (22.0%), 75 in Respiratory and Critical Care Medicine (8.3%), 74 in Neurology (8.2%), 63 in Orthopedics (7.0%) and 55 in Endocrinology departments (6.1%), and the difference in the positive rate among different departments were also statistically significant (χ(2) = 271.585, P < 0.05). Among the 480 cases who were followed-up, 215 (44.79%) were lost to follow-up, 84 cases (39.07%) were unregistered, 77 cases (16.04%) were untreated, 15 cases (19.48%) were unaware of their state of illness, 46 cases (59.74%) were diagnosed without concern, 16 cases (20.78%) were diagnosed but did not take medicine, 60 cases were under treatment, and 29 cases were mostly on counterfeit drugs (48.33%). Conclusion: Comprehensive diagnosis and treatment education to non-specialist clinicians and timely manner regular follow-up of patients is a key factor and an important link to formulate a simple, easy and sustainable model to improve the efficiency of screening, diagnosis, and treatment of hepatitis C micro-elimination strategy in hospital. In addition, it will also play an important role in achieving the strategic goal of "eliminating hepatitis C as a public health threat by 2030".

3D-Printing Damage-Tolerant Architected Metallic Materials with Shape Recoverability via Special Deformation Design of Constituent Material

Architected metallic materials generally suffer from a serious engineering problem of mechanical instability manifested as the emergence of localized deformation bands and collapse of strength. They usually cannot exhibit satisfactory shape recoverability due to the little recoverable strain of metallic constituent material. After yielding, the metallic constituent material usually exhibits a continuous low strain-hardening capacity, giving the local yielded regions of architecture low load resistance and easily developing into excessive deformation bands, accompanied by the collapse of strength. Here, a novel constituent material deformation design strategy has been skillfully proposed, where the low load resistance of yielded regions of the architecture can be effectively compensated by the significant self-strengthening behavior of constituent material, thus avoiding the formation of localized deformation bands and collapse of strength. To substantiate this strategy, shape-memory alloys (SMAs) are considered as suitable constituent materials for possessing both self-strengthening behavior and shape-recovery function. A 3D-printing technique was adopted to prepare various NiTi SMA architected materials with different geometric structures. It is demonstrated that all of these architected metallic materials can be stably and uniformly compressed by up to 80% without the formation of localized bands, collapse of strength, and structural failure, exhibiting ultrahigh damage tolerance. Furthermore, these SMA architected materials can display more than 98% shape recovery even after 80% deformation and excellent cycle stability during 15 cycles. This work exploits the amazing impact of constituent materials on constructing supernormal properties of architected materials and will open new avenues for developing high-performance architected metallic materials.

Genetic in situ engineering of myeloid regulatory cells controls inflammation in autoimmunity

The ability of myeloid regulatory cells (MRCs) to control immune responses and to promote tolerance has prompted enormous interest in exploiting them therapeutically to treat inflammation, autoimmunity, or to improve outcomes in transplantation. While immunomodulatory small-molecule compounds and antibodies have provided relief for some patients, the dosing entails high systemic drug exposures and thus increased risk of off-target adverse effects. More recently, MRC-based cell-therapy products have entered clinical testing for tolerance induction. However, the elaborate and expensive protocols currently required to manufacture engineered MRCs ex vivo put this approach beyond the reach of many patients who might benefit. A solution could be to directly program MRCs in vivo. Here we describe a targeted nanocarrier that delivers in vitro-transcribed mRNA encoding a key anti-inflammatory mediator. We demonstrate in models of systemic lupus erythematosus that infusions of nanoparticles formulated with mRNA encoding glucocorticoid-induced leucine zipper (GILZ) effectively control the disease. We further establish that these nanoreagents are safe for repeated dosing. Implemented in the clinic, this new therapy could enable physicians to treat autoimmune disease while avoiding systemic treatments that disrupt immune homeostasis.

The Chinese mitten crab genome provides insights into adaptive plasticity and developmental regulation

The infraorder Brachyura (true or short-tailed crabs) represents a successful group of marine invertebrates yet with limited genomic resources. Here we report a chromosome-anchored reference genome and transcriptomes of the Chinese mitten crab Eriocheir sinensis, a catadromous crab and invasive species with wide environmental tolerance, strong osmoregulatory capacity and high fertility. We show the expansion of specific gene families in the crab, including F-ATPase, which enhances our knowledge on the adaptive plasticity of this successful invasive species. Our analysis of spatio-temporal transcriptomes and the genome of E. sinensis and other decapods shows that brachyurization development is associated with down-regulation of Hox genes at the megalopa stage when tail shortening occurs. A better understanding of the molecular mechanism regulating sexual development is achieved by integrated analysis of multiple omics. These genomic resources significantly expand the gene repertoire of Brachyura, and provide insights into the biology of this group, and Crustacea in general.

African lungfish genome sheds light on the vertebrate water-to-land transition

Lungfishes are the closest extant relatives of tetrapods and preserve ancestral traits linked with the water-to-land transition. However, their huge genome sizes have hindered understanding of this key transition in evolution. Here, we report a 40-Gb chromosome-level assembly of the African lungfish (Protopterus annectens) genome, which is the largest genome assembly ever reported and has a contig and chromosome N50 of 1.60 Mb and 2.81 Gb, respectively. The large size of the lungfish genome is due mainly to retrotransposons. Genes with ultra-long length show similar expression levels to other genes, indicating that lungfishes have evolved high transcription efficacy to keep gene expression balanced. Together with transcriptome and experimental data, we identified potential genes and regulatory elements related to such terrestrial adaptation traits as pulmonary surfactant, anxiolytic ability, pentadactyl limbs, and pharyngeal remodeling. Our results provide insights and key resources for understanding the evolutionary pathway leading from fishes to humans.

African Arowana Genome Provides Insights on Ancient Teleost Evolution

Osteoglossiformes is a basal clade of teleost, evolving since the Jurassic period. The genomes of Osteoglossiformes species would shed light on the evolution and adaptation of teleost. Here, we established a chromosome-level genome of African arowana. Together with the genomes of pirarucu and Asian arowana, we found that they diverged at ∼106.1 million years ago (MYA) and ∼59.2 MYA, respectively, which are coincident with continental separation. Interestingly, we identified a dynamic genome evolution characterized by a fast evolutionary rate and a high pseudogenization rate in African arowana and pirarucu. Additionally, more transposable elements were found in Asian arowana which confer more gene duplications. Moreover, we found the contraction of olfactory receptor and the expansion of UGT in African arowana might be related to its transformation from carnivore to be omnivore. Taken together, we provided valuable genomic resource of Osteoglossidae and revealed the correlation of biogeography and teleost evolution.

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An evolutionary model of Osteoglossidae along the continental drift is provided

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A faster evolving rate of African arowana than Asian arowana is revealed

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The gene duplications of Asian arowana are related to more class I TE insertions

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A mechanism of African arowana’s feeding habits transition is proposed.

Transfemoral-venous transcatheter access to left ventricle through the created communication of inter-ventricular septum with the assistance of arterio-venous circuit

Background

During transcatheter aortic/mitral valve replacement (TA/MVR), current available routes are limited due to unfavorable entry-angle, vessel-anatomy or mini-thoracotomy. Through created communication of inter-ventricular septum (C-IVS), transfemoral venous transcatheter access to left ventricle becomes feasible with the assistance of arterio-venous circuit.

Purpose

The study was conducted to investigate the feasibility and safety of transfemoral-venous transcatheter access to left ventricle through the created C-IVS in a swine model.

Methods

Via femoral artery, transcatheter puncture of mid-IVS was performed with the custom-made nickel-titanium needle (0.038-inch, needle-tip bent 60 degrees automatically associated with increased hardness when temperature was above 30°C) and 6F-sheath in 20 healthy Chinese mini-swine. Then femoral arterio-venous circuit was established through created C-IVS with hydrophilic guidewire in all swine, and femoral veno-venous circuit was further created through C-IVS and atrial septum in 4 swine. After pre-dilation of C-IVS, a 20F-sheath was introduced into left ventricle transvenously over the guidewire. Furthermore, transfemoral-venous TAVR was attempted with this approach in one swine. C-IVS was evaluated postoperatively and was further confirmed pathologically 2 months later.

Results

All transcatheter puncture of IVS was performed successfully in left ventricle and the thickness of mid-IVS was 7.67±0.98 mm. During the puncture, ventricular fibrillation occurred in one swine (successfully defibrillation) and only isolated ventricular premature beats/non-sustained ventricular tachycardia were observed in other swine. In all swine, femoral arterio-venous/veno-venous circuit was established via C-IVS, and the 20F-sheath was introduced into left ventricle safely through femoral vein and C-IVS. With the aid of vessel circuit, the 20F-sheath was further advanced into aorta in 16 swine (the entry-angle was 145.3±12.2 degrees) and into left atrium in 4 swine. After the procedure, there was one swine with moderate tricuspid regurgitation and 5 swine with mild residual shunt (2.6±0.7 mm). In addition, epicardial coronary arteries were normal in all swine. Two months later, residual shunt was still detected in 3 swine and the communication was confirmed pathologically. In other swine, there was no defect of IVS and mild replacement-scar was identified along C-IVS. In the swine underwent transfemoral-venous TAVR, prosthetic valve was deployed successfully with good function.

Conclusions

With the aid of vessel circuit, transfemoral-venous transcatheter access to left ventricle is feasible and safe via C-IVS, and transfemoral-venous TAVR was achieved successfully using this novel approach with favorable entry-angle.

Figure 1

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): National Natural Science Foundation of China

OP0095 A DECISION MODEL OF LABIAL GLAND BIOPSY BASED ON B-MODE ULTRASONOGRAPHY WITH SHEAR-WAVE ELASTOGRAPHY IN PATIENTS WITH SUSPECTED SJÖGREN’S SYNDROME

Background:

Focal lymphocytic sialadenitis defined as focus score (FS) ≥1 on labial gland (LG) biopsy plays an integral role in various classification criteria of Sjögren’s syndrome (SS). However, suspected patients often hesitate to receive a biopsy; and rheumatologists hope a decision for biopsy based on a high predicted incidence of FS≥1, or against biopsy based on an absolutely low predicted incidence.

Objectives:

To build a decision model of LG biopsy based on B-mode ultrasonography (US) with shear-wave elastography (SWE) in patients with suspected SS.

Methods:

Patients who had at least one symptom of oral dryness (based on AECG questions) or had anti-SSA positive were recruited and signed a written informed consent. Bilateral parotid (PG) and submandibular glands (SMG) were examined with B-mode US which graded the echostructure of each gland on a scoring system scaled 0 to 4 (US score), and SWE which described the elasticity of glands. Then LG biopsy was performed.

Results:

(1)Ninety-one patients whose mean age was 43±15 years were enrolled and 93% of them were female. Anti-SSA was detected in 77 patients (85%) and 28 patients (31%) showed unstimulated whole saliva flow rate (USFR)≤0.1mL/mim. There were 57 patients (63%) showing FS≥1 on LG biopsy. Sixty-three patients (69%) were classified as primary SS, 10 patients (10%) were secondary SS, 18 patients (20%) were uCTD and one patient was RA without SS.

(2)US scores were equal between PG and SMG in 59 patients (65%), while the rest patients showed different US scores between two glands: 7 patients (8%) showed higher US scores in PG and 25 patients (27%) showed higher scores in SMG. In each pair of glands US scores were equal. SWE values in PG or SMG of US score 1, 2 or 3 were significantly higher than those of US score 0, while SWE values in glands of US score 4 became declined and showed no significant difference from those with US score 0 (Figure 1A).

(3)Heatmap showed US scores in either major salivary gland of patients with FS≥1 on LG biopsy were significantly higher than those with FS<1 (all p<0.001, Figure 1B). ROC curve showed a total US score (including bilateral PG and SMG) ≥9 and a total SWE value (including bilateral PG and SMG)≥30 could significantly recognize patients with FS≥1, respectively with specificity of 100% and 93% (Figure 1C). In this cohort, among 51 patients with a total US score ≥9 and/or a total SWE value≥30, 49 patients (96%) showed FS≥1 on LG biopsy; while two outliers showed total US scores were both 8 although combined SWE values≥30. Other 29 patients showed total US scores≤6 with total SWE values <30 and only one patient (3%) showed FS≥1 on LG biopsy. The remaining 11 patients showed total US scores were 8 with total SWE values <30 and 64% of them (n=7) showed FS≥1.

Conclusion:

A preliminary decision model of LG biopsy based on B-mode US with SWE in patients with suspected SS were built in Table 1. For example, rheumatologists should reassess the need for biopsy if the incidence of FS≥1 would be <5%. Another cohort of patients with suspected SS is needed for further validation.

Table 1.

A preliminary decision model of LG biopsy based on B-mode US with SWE in patients with suspected SS

Algorithm*Comments on the decision of LG biopsyA total US score≥9 and/or a total SWE≥30The specificity of FS≥1 on biopsy is >93%. Biopsy is recommended. In some special cases (e.g. contraindicated to biopsy), this item is a potential alternative to LG biopsy.A total US score 7~8 with a total SWE <30It is hard to predict the result of FS, so biopsy is strongly recommended.A total US score≤6 with a total SWE <30The incidence of FS≥1 would be <5%. Rheumatologists should reassess the need for biopsy.

References:

None

Disclosure of Interests:

None declared

"Lattice Strain Matching"-Enabled Nanocomposite Design to Harness the Exceptional Mechanical Properties of Nanomaterials in Bulk Forms

Nanosized materials are known to have the ability to withstand ultralarge elastic strains (4-10%) and to have ultrahigh strengths approaching their theoretical limits. However, it is a long-standing challenge to harnessing their exceptional intrinsic mechanical properties in bulk forms. This is commonly known as "the valley of death" in nanocomposite design. In 2013, a breakthrough was made to overcome this challenge by using a martensitic phase transforming matrix to create a composite in which ultralarge elastic lattice strains up to 6.7% are achieved in Nb nanoribbons embedded in it. This breakthrough was enabled by a novel concept of phase transformation assisted lattice strain matching between the uniform ultralarge elastic strains (4-10%) of nanomaterials and the uniform crystallographic lattice distortion strains (4-10%) of the martensitic phase transformation of the matrix. This novel concept has opened new opportunities for developing materials of exceptional mechanical properties or enhanced functional properties that are not possible before. The work in progress in this research over the past six years is reported.

Transfemoral transcatheter puncture of interventricular septum in a swine model: A novel transfemoral-venous access to left ventricle with the assistance of arterio-venous circuit

OBJECTIVE

Via subclavian/jugular vein, successful puncture of interventricular septum (IVS) has been achieved transvenously. However, the approach was limited by acute entry-angle. The study was conducted to investigate a novel transcatheter puncture of IVS via femoral access and transfemoral-venous access to left ventricle (LV) through IVS.

METHODS

Via femoral artery, transcatheter puncture of mid-IVS was performed with a custom-made nickel-titanium needle and 6F-sheath in 16 healthy mini-swine. Then femoral arterio-venous circuit was established through IVS. After pre-dilation of IVS, a 20F-sheath was introduced into LV transvenously over-the-guidewire in 15 swine. Furthermore, transfemoral-venous TAVR was attempted with the approach in another swine. IVS was evaluated postoperatively and was further confirmed pathologically 2 months later.

RESULTS

All transcatheter puncture of IVS was performed successfully in LV and the mid-IVS thickness was 7.67 ± 0.98 mm. In all swine, femoral arterio-venous circuit was established via IVS, and a 20F-sheath was introduced into LV and aorta transfemoral-venously (entry-angle: 145.3 ± 12.2° in front view). After the procedure, there was one swine with moderate tricuspid-regurgitation and five swine with mild residual-shunt (2.6 ± 0.7 mm). Two months later, residual-shunt was still detected in three swine and the communication was confirmed pathologically. In other swine, no defect occurred and replacement-scar was identified along puncture-tract. In the swine underwent transfemoral-venous TAVR, prosthetic valve was deployed successfully with good function.

CONCLUSIONS

Transfemoral transcatheter puncture of IVS is feasible and safe in a swine model, and large sheath can be introduced into LV transfemoral-venously using the novel access with the aid of vessel circuit.

N-Doped Mesoporous Carbons: From Synthesis to Applications as Metal-Free Reduction Catalysts and Energy Storage Materials

N-doped mesoporous carbons, NMCs, have attracted intensive attention recently and have shown potential applications in various scientific fields including catalysis and energy conversion/storage. Via modification with foreign N elements and construction of mesoporous structures for NMCs, their electronic and spin structure, as well as their porosity can be greatly tailored. And the resultant electron-donor property, surface wettability, conductivity, ion/molecular transfer and reactivity are changed accordingly. In this review, we will summarize the recent research progress of these metal-free NMCs, with an emphasis on their synthesis and performance, especially for their synthetic strategy and catalytic properties toward oxygen and nitro compound reductions, as well as their electrochemical properties as electrode materials for lithium-ion/sulfur batteries and supercapacitors. We hope for future developments, such as controlling doping methods more precisely, generating more active sites by N-doping, and finding wider applications of NMCs in other fields.