羟基磷灰石吸附性能的研究进展

羟基磷灰石是人体和动物骨骼的主要无机矿物成分,具有良好的生物相容性和生物活性,是较好的生物材料。随着研究工作的深入进行,研究人员发现羟基磷灰石具有较强的吸附作用,在吸附并回收利用地方饮用水中过量的氟离子和工业废水中的重金属离子方面具有非常广阔的应用前景。文章综述了羟基磷灰石吸附性能的应用研究近况,并对羟基磷灰石的发展前景进行了展望。     

多孔型颗粒羟基磷灰石填充颌骨腔性骨缺损的临床观察

应用多孔型颗粒羟基磷灰石（ＰａｒｔｉｃｕｌａｔｅＨｙｄｒｏｘｙａｐａｔｉｔｅ，ＰＨＡ）人工骨填充颌骨腔性骨缺损３２例，术后随访１～６年，３１例获得良好疗效，１例失败．观察结果表明，ＰＨＡ填充颌骨骨腔，有利止血和消灭死腔，减少术后感染，加快骨缺损修复，增加患区牙齿稳固性和咀嚼功能恢复．并且ＰＨＡ生物相容性良好，术后无并发症及不良反应，操作简便，病员无痛苦，是一种较理想的骨腔充填材料     

浅谈孕期补钙

钙是人体内含量最多的一种无机元素。正常人体内钙的含量为1200--1400g，约占人体重量的1．5％一2．0％，其中99％存在于骨骼和牙齿中。另外1％的钙大多数呈离子状态存在于软组织、细胞外液和血液中，与骨钙保持着动态平衡。机体内的钙，一方面构成骨骼和牙齿，另一方面可参与各种生理功能和代谢过程，影响各个器官组织的活动。     

废弃蛋壳合成羟基磷灰石的方法比较

以废弃蛋壳为原料,分别通过水热法、微波法、煅烧法合成了羟基磷灰石.用钙磷比的定量测定和红外光谱进行了表征.比较了三种方法的优缺点.     

各种年龄及形态包皮组织中触觉小体观察

目的观察不同年龄和形态包皮组织中触觉小体。方法收集3-59岁包茎及包皮过长标本204例。用免疫组化方法对标本中的触觉小体进行染色，观察每例标本中触觉小体密度。结果包皮过长中触觉小体密度从婴幼儿期渐增加，15岁包皮触觉小体密度达到最高，20岁前包茎和包皮过长中触觉小体密度无明显差异，其后，包皮过长呈下降趋势。男子包皮过长中的触觉小体的密度与年龄之间呈负相关并具有统计学意义（r=0．236，P=0．009），包茎虽呈正相关而无显著性（r=0．193，P=0．084）。结论包皮过长组织中触觉小体的密度与外生殖器发育成熟同步，并与成年男子性功能状态一致。成年包茎中触觉小体持续较高水平可能是一种生理性代偿．     

杂说生活中的钙

<正>按化学元素在人体内所占质量的大小来排名,钙元素排第五位,占人体总质量的1.5%～2%（前四位分别是氧65%、碳18%、氢10%、氮3%）。氧、碳、氢、氮是蛋白质的最主要元素,人体的肌肉、皮肤、内脏的主要成分都是蛋白质,所以这四个元素排在前四位很好理解。钙元素主要存在于人的骨骼和牙齿中,它们也是人体组织中最坚硬的部分。为什么含钙的骨骼和牙齿会如此坚硬呢？     

一氧化氮腹膜淋巴孔调控与中药治疗腹水机理探讨

目的：研究中药与一氧化氮（NO）的腹膜淋巴孔调控，探讨中药复方的消腹水机理，方法：通过扫描电镜观察和计算机图像处理定量分析，测定腹膜淋巴孔孔径、面积和开放密度，同时测定尿钠浓度。结果：（1）中药组腹膜淋巴孔孔径，面积和开放密度均增大，尿钠排出量显著增多（P＜0．01）；（2）NO供体硝普钠组腹膜淋巴孔孔径，面积和开放密度均增加（P＜0．01或P＜0．05）；（3）在给中药时，又给NO合酶抑制剂L－硝基精氨酸，腹膜淋巴孔孔径，面积及开放密度均减小（P＜0．01）。结论：本中药复方有较好的调控淋巴孔促尿钠离子排出的作用，结果提示，中药可能是通过升高内源NO浓度，舒张腹膜淋巴孔达到消腹水作用。     

熔盐法制备PMN-PT弛豫铁电陶瓷的显微结构及性能

本文研究了熔盐法合成的PMN-PT粉末的烧结特性，以及合成工艺对PMN-PT陶瓷致密度，显微结构和介电性能的影响。结果显示，熔盐合成的粉料具有较小的颗粒尺寸和良好的分散性，能够降低陶瓷的烧结温度，在1150～1180℃范围烧结可得到致密度≥96％的PMN-PT陶瓷。在1100～1200℃烧结温度范围，硫酸盐熔盐体系制备的陶瓷呈沿晶断裂，而氯化物熔盐体系制备的陶瓷均呈穿晶断裂。在相同的烧结温度下，氯化物熔盐制备的陶瓷的晶粒尺寸明显大于硫酸盐熔盐体系的陶瓷的晶粒尺寸。用熔盐法制备的组分为0．67PMN．0．33PT陶瓷具有优良的压电和介电性能。在1175℃／2h烧结条件下，制备的0．67PMN-0．33PT陶瓷的最大介电常数为29385，d33≈660pC／N。     

sICAM-1在牙周炎患者龈沟液中的含量

研究了牙周炎患者龈沟液可溶性细胞间粘附分子（ｓ Ｉ Ｃ Ａ Ｍ １）的含量⒚牙周炎患者 ２３ 例,４６ 个牙齿;正常对照２０ 例,２０ 个牙齿,用 Ｅ Ｌ Ｉ Ｓ Ａ 法检测牙周炎患者龈沟液ｓ Ｉ Ｃ Ａ Ｍ １ 的含量⒚正常对照龈沟液ｓ Ｉ Ｃ Ａ Ｍ １ 含量为（１４５．０１４±４３．７４５）ｎｇ／ｍ Ｌ ,男女间无显著性差异（ Ｐ＞ ０．０５）⒚牙周炎患者龈沟液ｓ Ｉ Ｃ Ａ Ｍ １ 的含量为（２５．３８９±８．４６１）ｎｇ／ｍ Ｌ,明显低于正常对照（ Ｐ＜ ０．０１）;一个牙齿３０ 秒龈沟液 ｓ Ｉ Ｃ Ａ Ｍ １ 总量,正常对照为（０．１７６４±０．０４３２）ｎｇ,牙周炎患者为（０．０８３０±０．０１９７）ｎｇ,二者之间有显著性差异（ Ｐ＜ ０．０１）⒚表明龈沟液ｓ Ｉ Ｃ Ａ Ｍ １ 含量的降低与牙周炎有关⒚     

你也能成为古生物专家

化石是埋藏在地层里的古代生物的遗物。最常见的化石是由牙齿和骨骼形成的。古代动物死后,尸体的内脏、肌肉等柔软的组织很快便会腐烂,牙齿和骨骼因为有机质较少,无机质较多,所能能保存较长的时间。由于化石中的大量矿物质是极为细致地慢慢替代其中的有机质,所以能完整地保存牙     

Students' Reactions to the Introduction of Videoconferencing for Classroom Instruction

This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.     

Cooler temperatures inductive to locust outbreaks

Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.     

Exploring Multiplexity: Social Network Structures in a Computer-Supported Distance Learning Class

A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.     

The Role of Intermediating Institutions in the Diffusion of Electronic Data Interchange (EDI): How Industry Associations Intervened in Denmark, Finland, and Hong Kong

Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.     

How Electronic Publishers are Protecting Against Piracy: Doubts About Technical Systems of Protection

The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means.     

Rough Justice: A Statistical Assessment of ICANN's Uniform Dispute Resolution Policy

Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP.     

Prevalence of soft neurological signs in Chinese people

Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.     

Monoculture Rubber Plantations Have Negative Ef ects on Controlling Splash Erosion

<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence     

Chinese Scientists Use Earth Observation Technologies to Study and Protect Wild Camels

<正>Chinese scientists plan to apply Earth Observation technologies to protect the critically endangered wild camels(Camelus ferus).With the help of remote sensing,satellite positioning,geographical information system and wireless sensors networks,they will be able to access the distribution and population of the wild camels and protect their habitats.The project will be carried out by the International Research Center for Wild Camel Conservation,which was jointly established earlier this year by the Institute of Remote Sensing and Digital Earth(RADI)of the Chinese     

More than Skin Deep – Understand Skin Biology by Means of Dermatogenomics

<正>The Paul Gerson Unna Research Group on Dermatogenomics was founded in October 2012 at the Partner Institute for Computational Biology.The ultimate goal of the group is to understand the biology of skin and skin appendages.