Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
72,584
result(s) for
"Chen, Sun"
Sort by:
قصة الرياضة في الصين
في السنوات القليلة الماضية ، سطع وهج النفوذ الصيني على الصعيد الدولي وبات كثير من الناس يرغب في التعرف إلى الصين وإلى حياة شعبها اليومية، ومع انتشار معاهد كونفوشيوس في شتى أرجاء المعمورة ، ازداد عدد الطلاب ولا سيما الصغار الذين يرغبون بتعلم اللغة الصينية ولهذا الغرض تمت ترجمة سلسلة كتب لمحة عن الصين المعاصرة لعدد من المؤلفين الصينين بإشراف لي لوشينغ وهي صادرة ومؤلفة من عشرة أجزاء يركز كل جزء منها على التعريف على أحد مجالات الحياة الصينية مثل الغذاء والنقل والأسرة والرياضية والفن والسياحة وما إلى ذلك بحيث يتعلم الطالب مابين 2500 إلى 3000 كلمة من كل كتاب وهذا ما يتطلبه امتحان كفاءة اللغة الصينية من الدرجة الخامسة وهكذا فإن القارئ على مدى صفحات الكتاب سيجد الكلمات الصينية متبوعة بشرح لها باللغة الإنجليزية وهذا ما يسهل على المتعلم القراءة والفهم.
Book
Actin cytoskeleton dynamics in mammalian oocyte meiosis
During mitosis, cells undergo symmetrical cell division, while oocyte meiotic maturation undergoes two consecutive, asymmetric divisions that generate a totipotent haploid oocyte and two small polar bodies not involved in DNA replication. This specialized division allows most maternal components to be maintained in the oocytes for early embryo development. Nuclear positioning, germinal vesicle breakdown, spindle migration, spindle rotation, chromosome segregation, and polar body extrusion are the most critical cellular processes during oocyte meiosis I and II, and a growing number of studies primarily using the mouse oocyte model revealed that actin filaments were critical for these processes, especially for spindle migration. Several important molecules have been reported to be involved in these processes. One family of molecules are the small GTPases, such as Rho GTPases, Ran GTPases, and Rab GTPases and another are the actin nucleators, such as the formin family and the Arp2/3 complex. The present review summarizes recent progress made regarding the roles of actin filaments in the asymmetric oocyte division. Summary Sentence Actin filaments widely involve into multiple cellular processes such as nuclear positioning, germinal vesicle breakdown, spindle migration, chromosome segregation, spindle rotation and polar body extrusion in oocyte mammalian meiosis.
Journal Article
Extended topological valley-locked surface acoustic waves
Stable and efficient guided waves are essential for information transmission and processing. Recently, topological valley-contrasting materials in condensed matter systems have been revealed as promising infrastructures for guiding classical waves, for they can provide broadband, non-dispersive and reflection-free electromagnetic/mechanical wave transport with a high degree of freedom. In this work, by designing and manufacturing miniaturized phononic crystals on a semi-infinite substrate, we experimentally realized a valley-locked edge transport for surface acoustic waves (SAWs). Critically, original one-dimensional edge transports could be extended to quasi-two-dimensional ones by doping SAW Dirac “semimetal” layers at the boundaries. We demonstrate that SAWs in the extended topological valley-locked edges are robust against bending and wavelength-scaled defects. Also, this mechanism is configurable and robust depending on the doping, offering various on-chip acoustic manipulation,
e.g
., SAW routing, focusing, splitting, and converging, all flexible and high-flow. This work may promote future hybrid phononic circuits for acoustic information processing, sensing, and manipulation.
Here the authors provide experimental evidence of extended topological valley-locked states. By splicing together Dirac semimetals and topological insulators, they demonstrate reduced backscattering and enhanced matching of SAW with interdigital transducers proposing this system for topological acoustics devices.
Journal Article
Ferroptosis and Its Potential Role in the Physiopathology of Skeletal Muscle Atrophy
Skeletal muscle atrophy is a major health concern, severely affecting the patient’s mobility and life quality. In the pathological process of skeletal muscle atrophy, with the progressive decline in muscle quality, strength, and function, the incidence of falling, fracture, and death is greatly increased. Unfortunately, there are no effective treatments for this devastating disease. Thus, it is imperative to investigate the exact pathological molecular mechanisms underlying the development of skeletal muscle atrophy and to identify new therapeutic targets. Decreased muscle mass, strength, and muscle fiber cross-sectional area are typical pathological features and manifestations of skeletal muscle atrophy. Ferroptosis, an emerging type of programmed cell death, is characterized by iron-dependent oxidative damage, lipid peroxidation, and reactive oxygen species accumulation. Notably, the understanding of its role in skeletal muscle atrophy is emerging. Ferroptosis has been found to play an important role in the intricate interplay between the pathological mechanisms of skeletal muscle atrophy and its progression caused by multiple factors. This provides new opportunities and challenges in the treatment of skeletal muscle atrophy. Therefore, we systematically elucidated the ferroptosis mechanism and its progress in skeletal muscle atrophy, aiming to provide a comprehensive insight into the intricate relationship between ferroptosis and skeletal muscle atrophy from the perspectives of iron metabolism and lipid peroxidation and to provide new insights for targeting the pathways related to ferroptosis and the treatment of skeletal muscle atrophy.
Journal Article
PPARs-Orchestrated Metabolic Homeostasis in the Adipose Tissue
It has been more than three decades since peroxisome proliferator-activated receptors (PPARs) were first discovered. Many investigations have revealed the central regulators of PPARs in lipid and glucose homeostasis in response to different nutrient conditions. PPARs have attracted much attention due to their ability to improve metabolic syndromes, and they have also been proposed as classical drug targets for the treatment of hyperlipidemia and type 2 diabetes (T2D) mellitus. In parallel, adipose tissue is known to play a unique role in the pathogenesis of insulin resistance and metabolic syndromes due to its ability to “safely” store lipids and secrete cytokines that regulate whole-body metabolism. Adipose tissue relies on a complex and subtle network of transcription factors to maintain its normal physiological function, by coordinating various molecular events, among which PPARs play distinctive and indispensable roles in adipocyte differentiation, lipid metabolism, adipokine secretion, and insulin sensitivity. In this review, we discuss the characteristics of PPARs with special emphasis on the roles of the different isotypes in adipocyte biology.
Journal Article
Elastic pseudospin transport for integratable topological phononic circuits
Precise control of solid-state elastic waves’ mode content and coherence is of great use nowadays in reinforcing mechanical energy harvesting/storage, nondestructive material testing, wave-matter interaction, high sensitivity sensing, and information processing, etc. Its efficacy is highly dependent on having elastic transmission channels with lower loss and higher degree of freedom. Here, we demonstrate experimentally an elastic analog of the quantum spin Hall effects in a monolithically scalable configuration, which opens up a route in manipulating elastic waves represented by elastic pseudospins with spin-momentum locking. Their unique features including robustness and negligible propagation loss may enhance elastic planar-integrated circuit-level and system-level performance. Our approach promotes topological materials that can interact with solid-state phonons in both static and time-dependent regimes. It thus can be immediately applied to multifarious chip-scale topological phononic devices, such as path-arbitrary elastic wave-guiding, elastic splitters and elastic resonators with high-quality factors.
Precise control of elastic waves is of great use in current technologies. Here, Yu et al. realize the analogue of quantum spin Hall effects for the elastic waves in a plain plate consisting of identical perforated holes in wavelength scales.
Journal Article
Topologically protected one-way edge mode in networks of acoustic resonators with circulating air flow
Recent explorations of topology in physical systems have led to a new paradigm of condensed matters characterized by topologically protected states and phase transition, for example, topologically protected photonic crystals enabled by magneto-optical effects. However, in other wave systems such as acoustics, topological states cannot be simply reproduced due to the absence of similar magnetics-related sound-matter interactions in naturally available materials. Here, we propose an acoustic topological structure by creating an effective gauge magnetic field for sound using circularly flowing air in the designed acoustic ring resonators. The created gauge magnetic field breaks the time-reversal symmetry, and therefore topological properties can be designed to be nontrivial with non-zero Chern numbers and thus to enable a topological sonic crystal, in which the topologically protected acoustic edge-state transport is observed, featuring robust one-way propagation characteristics against a variety of topological defects and impurities. Our results open a new venue to non-magnetic topological structures and promise a unique approach to effective manipulation of acoustic interfacial transport at will.
Journal Article
Liquid-liquid phase separation and extracellular multivalent interactions in the tale of galectin-3
Liquid-liquid phase separation (LLPS) explains many intracellular activities, but its role in extracellular functions has not been studied to the same extent. Here we report how LLPS mediates the extracellular function of galectin-3, the only monomeric member of the galectin family. The mechanism through which galectin-3 agglutinates (acting as a “bridge” to aggregate glycosylated molecules) is largely unknown. Our data show that its N-terminal domain (NTD) undergoes LLPS driven by interactions between its aromatic residues (two tryptophans and 10 tyrosines). Our lipopolysaccharide (LPS) micelle model shows that the NTDs form multiple weak interactions to other galectin-3 and then aggregate LPS micelles. Aggregation is reversed when interactions between the LPS and the carbohydrate recognition domains are blocked by lactose. The proposed mechanism explains many of galectin-3’s functions and suggests that the aromatic residues in the NTD are interesting drug design targets.
Galectin-3 consists of an unstructured N-terminal domain (NTD) and a structured carbohydrate-recognition domain and agglutinates neutrophils and glycosylated molecules in the extracellular milieu. Here the authors combine biophysical and biochemical experiments with NMR measurements and show that the galectin-3 NTD undergoes liquid-liquid phase separation (LLPS) and agglutinates other molecules through this process.
Journal Article
The influence of the environment and lifestyle on myopia
Background
Myopia, commonly known as near-sightedness, has emerged as a global epidemic, impacting almost one in three individuals across the world. The increasing prevalence of myopia during early childhood has heightened the risk of developing high myopia and related sight-threatening eye conditions in adulthood. This surge in myopia rates, occurring within a relatively stable genetic framework, underscores the profound influence of environmental and lifestyle factors on this condition. In this comprehensive narrative review, we shed light on both established and potential environmental and lifestyle contributors that affect the development and progression of myopia.
Main body
Epidemiological and interventional research has consistently revealed a compelling connection between increased outdoor time and a decreased risk of myopia in children. This protective effect may primarily be attributed to exposure to the characteristics of natural light (i.e., sunlight) and the release of retinal dopamine. Conversely, irrespective of outdoor time, excessive engagement in near work can further worsen the onset of myopia. While the exact mechanisms behind this exacerbation are not fully comprehended, it appears to involve shifts in relative peripheral refraction, the overstimulation of accommodation, or a complex interplay of these factors, leading to issues like retinal image defocus, blur, and chromatic aberration. Other potential factors like the spatial frequency of the visual environment, circadian rhythm, sleep, nutrition, smoking, socio-economic status, and education have debatable independent influences on myopia development.
Conclusion
The environment exerts a significant influence on the development and progression of myopia. Improving the modifiable key environmental predictors like time spent outdoors and engagement in near work can prevent or slow the progression of myopia. The intricate connections between lifestyle and environmental factors often obscure research findings, making it challenging to disentangle their individual effects. This complexity underscores the necessity for prospective studies that employ objective assessments, such as quantifying light exposure and near work, among others. These studies are crucial for gaining a more comprehensive understanding of how various environmental factors can be modified to prevent or slow the progression of myopia.
Journal Article
Digital technology innovation, supply chain resilience and enterprise performance-The case of listed automotive parts manufacturing companies
Digital technology innovation (DTI) is the core driving force for the development of the digital economy. This paper brings digital technology innovation and the supply chain of auto parts manufacturing under the same framework. This paper uses Stata 18 to empirically analyze the panel data of 130 A-share auto parts listed companies in Shanghai and Shenzhen from 2010 to 2022. The digital technology innovation indicator is divided into three levels: substantial digital technology innovation (SDTI), non-substantial digital technology innovation (NDTI), overall digital technology innovation (ODTI). To explore its impact mechanism on enterprise performance. The empirical results show that: (1) Digital technological innovation (DTI) has a positive and significant impact on enterprise performance, and supply chain resilience plays a mediating role in the relationship between digital technology innovation and enterprise performance, and R&D investment (RDI) positively moderates the role of supply chain resilience in promoting enterprise performance. (2) Heterogeneity analysis showed that the impact of supply chain resilience on enterprise performance was more significant in small and medium-sized enterprises. There are significant differences between different groups of business ownership. In economically underdeveloped regions, the effect of digital technology innovation on enterprise performance is more significant. This paper complements the perspective of supply chain to study the relationship between digital technology innovation and enterprise performance, expands the existing research, and its heterogeneity analysis provides new insights for understanding China’s auto parts manufacturing industry. This provides a basis for strengthening digital technology innovation and promoting the sustainable development of the auto parts industry.
Journal Article