In vivo imaging of the neuronal response to spinal cord injury:a narrative review

Deciphering the neuronal response to injury in the spinal cord is essential for exploring treatment strategies for spinal cord injury(SCI).However,this subject has been neglected in part because appropriate tools are lacking.Emerging in vivo imaging and labeling methods offer great potential for observing dynamic neural processes in the central nervous system in conditions of health and disease.This review first discusses in vivo imaging of the mouse spinal cord with a focus on the latest imaging techniques,and then analyzes the dynamic biological response of spinal cord sensory and motor neurons to SCI.We then summarize and compare the techniques behind these studies and clarify the advantages of in vivo imaging compared with traditional neuroscience examinations.Finally,we identify the challenges and possible solutions for spinal cord neuron imaging.

QGAE:用于生成问答对的端到端无答案问题生成模型

问题生成的目标是生成有意义且流畅的问题,以增加可用数据来解决问答类型标注语料库的缺乏问题。以带有可选答案的未注释文本作为输入内容,问题生成可以根据是否提供答案分为两种类型:有答案型和无答案型。即使在提供答案的情况下,生成问题也是具有挑战性的,更不用说在没有提供答案的情况下,对于人类和机器来说生成高质量的问题更加困难。为了解决这个问题,我们提出了一种名为QGAE的新型端到端模型,它能够通过直接提取候选答案,将无答案的问题生成转化为有答案的问题生成。这种方法有效地利用未标记的数据来生成高质量的问答对,其端到端的设计使其比多阶段方法更加方便,后者需要至少两个预训练模型。此外,我们的模型获得了更好的平均分数和更大的多样性。我们的实验结果表明,QGAE在生成问答对方面取得了显著的进展,成为了一种充满潜力的问题生成方法。

Bench-to-bedside strategies for osteoporotic fracture: from osteoimmunology to mechanosensation

Osteoporosis is characterized by a decrease in bone mass and strength, rendering people prone to osteoporotic fractures caused by low-energy forces. The primary treatment strategy for osteoporotic fractures is surgery;however, the compromised and comminuted bones in osteoporotic fracture sites are not conducive to optimum reduction and rigid fixation. In addition, these patients always exhibit accompanying aging-related disorders, including high inflammatory status, decreased mechanical loading and abnormal skeletal metabolism, which are disadvantages for fracture healing around sites that have undergone orthopedic procedures. Since the incidence of osteoporosis is expected to increase worldwide, orthopedic surgeons should pay more attention to comprehensive strategies for improving the poor prognosis of osteoporotic fractures. Herein, we highlight the molecular basis of osteoimmunology and bone mechanosensation in different healing phases of elderly osteoporotic fractures, guiding perioperative management to alleviate the unfavorable effects of insufficient mechanical loading, high inflammatory levels and pathogen infection. The well-informed pharmacologic and surgical intervention, including treatment with anti-inflammatory drugs and sufficient application of antibiotics, as well as bench-to-bedside strategies for bone augmentation and hardware selection, should be made according to a comprehensive understanding of bone biomechanical properties in addition to the remodeling status of osteoporotic bones, which is necessary for creating proper biological and mechanical environments for bone union and remodeling. Multidisciplinary collaboration will facilitate the improvement of overall osteoporotic care and reduction of secondary fracture incidence.

Skeleton-vasculature chain reaction: a novel insight into the mystery of homeostasis

Angiogenesis and osteogenesis are coupled.However,the cellular and molecular regulation of these processes remains to be further investigated.Both tissues have recently been recognized as endocrine organs,which has stimulated research interest in the screening and functional identification of novel paracrine factors from both tissues.This review aims to elaborate on the novelty and significance of endocrine regulatory loops between bone and the vasculature.In addition,research progress related to the bone vasculature,vessel-related skeletal diseases,pathological conditions,and angiogenesis-targeted therapeutic strategies are also summarized.With respect to future perspectives,new techniques such as single-cell sequencing,which can be used to show the cellular diversity and plasticity of both tissues,are facilitating progress in this field.Moreover,extracellular vesicle-mediated nuclear acid communication deserves further investigation.In conclusion,a deeper understanding of the cellular and molecular regulation of angiogenesis and osteogenesis coupling may offer an opportunity to identify new therapeutic targets.

Effect of rice-rice-rape rotation on physicochemical property and bacterial community of rhizosphere soil

Through collecting rhizosphere soil sample from a 30-year long-term fixed location test site that use“rice-ricerape”crop rotation(RRR)and“rice-rice-fallow”continuous cropping systems(RRF),this paper investigated effects of long-term crop rotation on physicochemical property and bacterial community of rhizosphere soil.Results showed that total nitrogen(TN),total phosphorus(TP)and available potassium(AK)contents in rhizosphere soil under long-term RRR were decreased by 28.09%,15.69%and 6.25%respectively.Alkali-hydrolyzable nitrogen(AN)and available phosphorus(AP)contents were 10.59%and 13.25%higher than those of soil in RRF respectively.Three soil samples collected during different periods also showed that RRR resulted in a lower rhizosphere soil pH than RRF.Clone library analysis revealed that significant difference in rhizosphere soil bacterial community was observed between RRR and RRF continuous cropping.Abundance ofα-Proteobacteria,β-Proteobacteria andγ-Proteobacteria were higher in rhizosphere soil of RRR compared to RRF.pH of rhizosphere soil was significantly correlated with Acidobacteria level,while total organic carbon(TOC)content was significantly correlated with Proteobacteria level.Long-term RRR enhanced conversion of N and P in rhizosphere soil,increased bio-availability to crop,and promoted diversity of soil bacterial community.Bacterial diversity in RRR could be ecological significance in maintaining soil fertility and functionality.

Influence of rotation system on siderophere-producing microorganism(SPM) in rhizosphere soil of southern China

Soil siderophores are important for crop growth,benefit ferric iron absorption of root,and are affected by cropping patterns.The objective of this study was to evaluate the quantity of siderophores in soil of 2 continuous crop rotation patterns over 30 years in Anren country,China.Quantity and siderophore-producing capability of microorganisms in rice-riceoilseed rape(DDY)rotation and rice-rice(DD)rontinuous cropping rhizosphere soil were tested and analyzed by chrome azurol S method.Isolated strains were used to identify siderophore-producing microorganism(SPM)by PCR amplification and DNA sequencing.Results showed that 9 siderophore-producing bacteria strains were isolated from DDY rhizosphere soil while 7 strains were identified from DD rhizosphere soil.The mean solubility index which representing siderophore-producing capability of strains was 3.05.PCR amplification results indicated that bacterial were the major SPM in soil.This research indicates that crop rotation systems could drive microorganisms to produce siderophores and enrich them in bacterial communities.

CEPC Technical Design Report

The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.

Clinical guidelines for indications,techniques,and complications of autogenous bone grafting

Autogenous bone grafts have long been considered the“gold standard”and most effective material in bone regeneration procedures.[1]Autogenous bone grafts are used to repair bone defects caused by nonunion,infection,tumor resection,and spinal and joint fusion.[2]It has been reported that more than 200,000 autologous bone grafts are performed in the United States each year.[3]Although there are no specific statistics on the annual number of bone grafts performed in China,autologous bone grafting is the most common surgical technique in orthopedics.The iliac crest remains the most common donor site,along with the fibula,ribs,tibial metaphysis,proximal humerus,distal radius,and greater trochanter.[4,5]Various bone-graft options provide different amounts and qualities of cortical,cancellous,and corticocancellous bone.[6,7]Autogenous bone graft is osteogenic,histocompatible,provides structural support.

Simultaneous dual-region two-photon imaging of biological dynamics spanning over 9 mm in vivo

Biodynamical processes,especially in system biology,that occur far apart in space may be highly correlated.To study such biodynamics,simultaneous imaging over a large span at high spatio-temporal resolutions is highly desired.For example,large-scale recording of neural network activities over various brain regions is indispensable in neuroscience.However,limited by the field-of-view(FoV)of conventional microscopes,simultaneous recording of laterally distant regions at high spatio-temporal resolutions is highly challenging.Here,we propose to extend the distance of simultaneous recording regions with a custom micro-mirror unit,taking advantage of the long working distance of the objective and spatio-temporal multiplexing.We demonstrate simultaneous dual-region two-photon imaging,spanning as large as 9 mm,which is 4 times larger than the nominal FoV of the objective.We verify the system performance in in vivo imaging of neural activities and vascular dilations,simultaneously,at two regions in mouse brains as well as in spinal cords,respectively.The adoption of our proposed scheme will promote the study of systematic biology,such as system neuroscience and system immunology.

Application of photocrosslinkable hydrogels based on photolithography 3D bioprinting technology in bone tissue engineering

Bone tissue engineering(BTE)has been proven to be an effective method for the treatment of bone defects caused by different musculoskeletal disorders.Photocrosslinkable hydrogels(PCHs)with good biocompatibility and biodegradability can significantly promote the migration,proliferation and differentiation of cells and have been widely used in BTE.Moreover,photolithography 3D bioprinting technology can notably help PCHs-based scaffolds possess a biomimetic structure of natural bone,meeting the structural requirements of bone regeneration.Nanomaterials,cells,drugs and cytokines added into bioinks can enable different functionalization strategies for scaffolds to achieve the desired properties required for BTE.In this review,we demonstrate a brief introduction of the advantages of PCHs and photolithography-based 3D bioprinting technology and summarize their applications in BTE.Finally,the challenges and potential future approaches for bone defects are outlined.

Simulation study of the performance of quadruple-GEM detectors

Background Gas Electron Multiplier(GEM)detectors are widely used for high-energy physics experiments,such as the triple-GEM detector installed in CMS,due to their excellent performance.A quadruple-GEM detector is regarded as the candidate for the upgrade projects of the High Luminosity LHC(HL-LHC).Method In this paper,key performance characteristics of quadruple-GEM detectors are studied in detail based on Monte Carlo simulation using the Garfield++and ANSYS software packages.The parameterization method is adopted.Result The spatial and time resolution,effective gain,efficiency,and electron transparency are obtained via simulation for different detector geometries and operating conditions.We create a quadruple-GEM structure that meets the geometric requirements of the CMS endcap muon detectors.Conclusion These studies help to understand the physical mechanisms of GEM detectors and provide references for the detector design,operating condition optimization and technical scheme selection in future applications.

Osteogenesis effects of magnetic nanoparticles modified-porous scaffolds for the reconstruction of bone defect after bone tumor resection

The treatment of bone defect after bone tumor resection is a great challenge for orthopedic surgeons.It should consider that not only to inhibit tumor growth and recurrence,but also to repair the defect and preserve the limb function.Hence,it is necessary to find an ideal functional biomaterial that can repair bone defects and inactivate tumor.Magnetic nanoparticles(MNPs)have its unique advantages to achieve targeted hyperthermia to avoid damage to surrounding normal tissues and promote osteoblastic activity and bone formation.Based on the previous stage,we successfully prepared hydroxyapatite(HAP)composite poly(lactic-co-glycolic acid)(PLGA)scaffolds and verified its good osteogenic properties,in this study,we produced an HAP composite PLGA scaffolds modified with MNPs.The composite scaffold showed appropriate porosity and mechanical characteristics,while MNPs possessed excellent magnetic and thermal properties.The cytological assay indicated that the MNPs have antitumor ability and the composite scaffold possessed good biocompatibility.In vivo bone defect repair experiment revealed that the composite scaffold had good osteogenic capacity.Hence,we could demonstrate that the composite scaffolds have a good effect in bone repair,which could provide a potential approach for repairing bone defect after bone tumor excision.