构建软骨支架的天然生物材料

关节软骨的自我修复能力有限,发生损伤后须进行修复或置换,然而传统的治疗方法难以达到理想的效果,组织工程技术为此难题带来了曙光。在组织工程三要素(种子细胞、支架材料、信号分子)中,支架材料起着至关重要的作用。对关节软骨支架材料进行了综述,重点介绍了软骨组织中天然存在的Ⅱ型胶原蛋白、透明质酸和硫酸软骨素3种生物材料,并就目前组织工程支架材料存在的问题和未来发展方向进行了讨论。     

NT3-壳聚糖支架诱导内源性神经发生修复脊髓损伤

通常情况下,脊髓损伤后损伤区的微环境是抑制的并充满炎性的,有限激活的内源性神经干/祖细胞几乎全部分化为了参与瘢痕形成的星形胶质细胞。我们的研究表明,生物材料系统可以激活成年哺乳动物中枢神经系统(CNS)内源性神经发生,并促进其迁移和向神经元定向分化。同时,这些新生神经元能够与宿主建立功能性神经网络,最终导致功能恢复,这为脑和脊髓损伤的治疗提供了新的策略和希望。为了进一步阐述其机制,我们采用加权基因共表达网络分析(Weighted gene co-expression network analysis,WGCNA)建立脊髓损伤后不同时空各类事件相应的基因模块/程序分析。这些客观的基因模块表达指标提示,生物材料系统在激活内源性神经发生的同时促进血管发生并降低了炎症反应。     

生物新材料在组织工程中的研究及利用

组织工程是指应用生命科学与工程的原理和方法,构建一个生物装置,来维护、增进人体细胞和组织的生长,以恢复受损组织或器官的功能。它的主要任务是实现受损组织或器官的修复和再建,延长寿命和提高健康水乎。其方法是,将特定组织细胞"种植"于一种生物相容性良好、可被人体逐步降解吸收的生物材料(组织工程材料)上,形成细胞一生物材料复合物;生物材料为细胞的增长繁殖提供三维空间和营养代谢环境;随着材料的降解和细胞的繁殖,形成新的具有与自身功能和形态相     

生物材料的发展现状与展望(综述)

概述了生物材料发展的三阶段,即惰性生物材料阶段（替代修复）、生物材料生物化阶段、组织工程支架材料阶段,指出目前组织工程的研究为生物材料提供了极大的发展机会：人们在可降解吸收生物材料研究方面取得了越来越多的成绩,认为天然可降解高分子材料是组织工程用支架材料的研究的重点,同时现阶段克隆技术等也为生物材料及组织工程的发展提出了挑战。     

神经干细胞移植的研究近况

神经干细胞能够再生和自我更新,并可以分化为神经元、星形胶质细胞和少突胶质细胞,因而神经干细胞移植可用于神经变性、脊髓损伤和神经脱髓鞘等疾病的治疗.本文主要总结了神经干细胞移植在帕金森氏病、脱髓鞘症、脊髓损伤、阿耳茨海默氏病和脑中风治疗中的应用.     

纤维基支架在骨和软骨组织再生中的应用

组织工程对于骨和软骨组织缺损的修复具有广阔的发展前景。在组织工程三要素之一的支架中,纤维基支架由于具有较大的比表面积、相互连通的多孔结构以及与天然细胞外基质相似等优势,在骨和软骨修复中展现出巨大的应用潜力。纤维支架的成型通常基于静电纺丝法、热致相分离法、自组装肽法和溶剂热法,血管化和软骨再生是此类支架在临床应用上面临的主要挑战。通过仿生天然骨和软骨组织的复杂结构、综合多种技术手段在结构和功能上设计纤维基三维多孔支架将是改善骨和软骨组织工程支架修复效果的主要发展方向。     

MicroRNA-124a对SCI继发性损伤的影响及相关机制研究

探究microRNA-124a(miR-124a)对脊髓损伤(spinal cord injury,SCI)继发性损伤的影响及相关机制.取90只健康成年Wistar大鼠建立SCI模型,随机分为3组,第1组术后仅注射生理盐水,为未治疗组;第2组术后注射骨髓基质细胞源神经干细胞(BMSCs-D-NSCs)治疗,为正常移植组;第3组术后注射携带miR-124a的骨髓基质细胞源神经干细胞(miR-124a-BMSCs-D-NSCs),为转染移植组.另选取60只健康成年Wistar大鼠作为对照组,仅给予假手术处理.采用HE染色观察大鼠的组织形态学变化,采用实时荧光定量PCR技术检测大鼠的miR-124a表达情况,并对损伤灶进行显微测量计算,比较脊髓功能恢复的BBB评分情况及脊髓组织损伤大小的情况.结果显示,SCI后,脊髓组织中miR-124a基因表达显著降低,脊髓神经功能也明显降低,miR-124a-BMSCs-D-NSCs能够有效地改善SCI,减少脊髓损伤组织范围及体积,还能改善中枢神经的功能.     

放飞希望 拥抱健康 ——一份来自海组织工程研究与开发中心的报告

组织工程是应用细胞生物学和工程学的原理,研究开发、修复和改善损伤组织和功能的生物替代物的一门科学,是继细胞生物学和分子生物学之后,生命科学发展史上又一新的里程碑,标志着医学将走出器官移植的范畴,步入制造组织和器官移植的新时代。 组织工程是一门多学科交叉的边缘学科,除了具有临床医学、生物材料学和细胞生物学三大学科支撑外,尚融汇了生物信息、生物化学工程、遗传学及计算机的原理和方法。因此,组织工程是二十一世纪具有巨大潜力的高技术产业。将产生巨大的社会效益和经济效益。为此,本刊记者走访了位于上海漕河泾高新技术开发区的国家863生物领域组织工程研发基地、上海组织工程研究与开发中心。     

骨髓间充质干细胞移植对脊髓损伤大鼠功能和结构修复的实验研究

观察骨髓间克质干细胞（MSC）移植对脊髓中度损伤大鼠运动功能的修复作用。方法：20只成年Sprague—Dawley（SD）大鼠随机移植组（n=10）和对照组（n=10）两组,均采用改良的A11en’s打击法遣成脊髓中度损伤（致伤冲量10g×4cm）。伤后1周,移植组于伤处移植大鼠MSC,而对照组仅注射等量PBS。分别于移植后1天,1周,2周,3周、4周用BBB评分观测大鼠的运动功能,并于移植后4周进行损伤脊髓的大体观察和组织学检测。结果：移植后1周两组动物运动功能恢复无明显差异。移植后2周、3周、4周,与对照组比较,移植组显著提高运动功能。移植后4周,移植组损伤脊髓的结构修复明显优于对照组。结论;脊髓损伤大鼠经MSC移植后能明显改善其运动功能和神经形态,MSC移植对脊髓损伤大鼠有治疗作用。     

嗅神经鞘细胞移植恢复大鼠损伤脊髓的功能

为探讨嗅神经鞘细胞移植恢复大鼠损伤脊髓的功能 ,将成年大鼠分为脊髓半切洞损伤组 (A组 )和脊髓半切洞损伤 嗅神经鞘细胞移植组 (B)组 ,手术后应用联合行为评分 (CBS)感觉诱发电位 (SEP)和运动诱发电位 (MEP)检查 ,测定脊髓功能恢复情况 .结果 2组CBS得分 ,A组 >B组 ,SEP和MEP潜峰时均A组 >B组 ,统计学分析均有显著性差异 (P <0 0 5 ) .表明移植嗅神经鞘细胞能恢复损伤脊髓的功能     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.