《心理发展与教育》三年论著引文统计分析

通过对<心理发展与教育)2004～2006年所发表论文的引文、语种、作者群、作者地区分布、发表论文作者机构、载文栏目等指标进行文献计量学分析,该刊三年共发表论文258篇.引文率99.61%,篇均15.25条.主要引文类型以期刊为主.占总引文量的94.71%,图书5.18%,自引率3.00%;作者合作论文222篇,合作率88.45%.作者地区分布主要在北京、广州、天津、重庆四个地区.其中北京居首,共发表173篇.栏目设置发文量最多的是认知与社会性发展119篇.论文多产机构为北京师范大学122篇.结果 表明:该刊论文作者人群众多、分布范围广、涉猎文献面广、研究课题引用文献比较高,专业人员利用新文献能力强、作者能紧跟本学科的研究发展方向.该刊是心理学领域具有权威性和代表性的刊物. 文率99.61%,篇均15.25条.主要引文类型以期刊为主.占总引文量的94.71%,图书5.18%,自引率3.00%;作者合作论文222篇,合作率88.45%.作者地区分布主要在北京、广州、天津、重庆四个地区.其中北京居首,共发表173篇.栏目设置发文量最多的是认知与社会性发展119篇.论文多产机构为北京师范大学122篇.结果 表明:该 论文作者人群众多、分布范围广、涉猎文献面广、研究课题引用文献比较高,专业人员利用新文献能力强、作者能紧跟本学科的研究发展方向.该刊是心理学领域具有权威性和代表性的刊物. 文率99.6     

Expression of mRNAs related to connective tissue metabolism in rat hepatic stellate cells and myofibroblasts

Hepatic stellate cells (HSC) and liver myofibroblasts (MFB) are two cell populations most likely responsible for the synthesis of most connective tissue components in fibrotic liver. They differ in their origin and location, and possibly in patterns of gene expression. Normal and carbon tetrachloride-cirrhotic livers from rats were used to isolate HSC. Liver was perfused with pronase and collagenase solutions, followed by centrifugation of the cell suspension on a density gradient. HSC were quiescent 2 days after plating on plastic but they became activated after another 5 days in culture. When the culture was passaged 5 times, its character changed profoundly as HSC were replaced by MFB. Microarray analysis was used to determine gene expression in quiescent HSC, activated HSC and MFB. The expression of 49 genes coding for connective tissue proteins, proteoglycans, metalloproteinases and their inhibitors, growth factors and cellular markers was determined. The pattern of gene expression changed during HSC activation and there were distinct differences between HSC and MFB. Little difference between normal cells and cells isolated from cirrhotic liver was found.     

血管内皮生长因子在子宫内膜异位症发病中的作用

目的探讨血管内皮生长因子(vascularendothelialgrowthfactor,VEGF)在子宫内膜异位症(endometriosis,EM)发病中的作用。方法应用免疫组织化学方法并结合图像分析技术。结果正常子宫内膜和EM在位内膜腺上皮细胞的VEGF随月经周期呈现规律性变化,分泌期腺上皮VEGF蛋白表达量显著高于增殖期(P<0.05)。在增殖期,EM在位子宫内膜腺上皮VEGF的表达与正常子宫内膜相比无明显差别,但在分泌期,EM在位子宫内膜腺上皮细胞中VEGF的表达强度明显高于正常子宫内膜(P<0.01)。EM在位内膜腺上皮的VEGF含量显著高于同组卵巢子宫内膜异位囊肿的异位腺上皮(P<0.01)。结论表明VEGF的表达异常与EM的发病有关。     

Junctional and extrajunctional acetylcholine receptors in normal and denervated frog muscle fibres

Summary Ionic channel properties of acetylcholine receptors located in, in the vicinity of, or far away from a frog neuromuscular junction were investigated by noise analysis of drug induced current fluctuations. For drugs applied to the junction, in certain cases two Lorentzian curves were necessary to describe the data. It is postulated that the reason for this observation is that a contribution from perijunctional receptors was being observed. The conductance of a single channel in the junction was independent of the nature of the agonist and had an average value of 17.9 pS (temperature range 8–25°C, solution buffered with Tris). After denervation for 21 days the conductance γ was 7.5 pS at extrajunctional locations. In the close neighbourhood of the junction (perijunctional receptors) values were found between 4 and 19 pS. The mean value of the open channel life-time τ in the endplate exposed to acetylcholine was 2.4 ms at 8–11°C. This value was 0.90 ms with carbachol, 0.50 ms with succinylcholine, 0.28 ms with decamethonium and 0.45 ms with nicotine. The receptors outside the endplate exhibited τ-values which at a given temperature were 2–3 times larger than those at the endplate. Raising the temperature to 23°C reduced all τ-values by factors of 2–3. It is concluded that at least two types of ACh-receptors with different properties exist in the muscle membrane, possibly produced by ACh-receptive units in different states of aggregation. This work was supported by the Deutsche Forschungsgemeinschaft, SFB 38, Project N     

Silver-Staining Nucleolar Organizer Region Quantification in Pituitary Adenomas

Nucleolar organizer regions (NORs) are segments of DNA, encoding for ribosomal RNA. They are associated with argyrophilic proteins and, thus, they can be localized through silver staining. A correlation has been shown between the number, the size, or the intranuclear localization of AgNORs, and the proliferative activity of cells. The aim of this study was to examine numerous features of AgNORs in pituitary adenomas and to relate them to immunohistochemical typing of tumor. Histologic slides from 32 pituitary tumors and one normal pituitary were silver-stained and analyzed with a computerized system for microscopic image analysis, supported by an AgNORmeter95 program. All the tumors were also immunocyto chemically characterized. We have found that gonadotropinomas, when compared with plurihormonal adenomas, revealed a lower proportion of nuclei with a single AgNOR and a higher percentage of marginal dots. Recurrent adenomas, when compared with primary adenomas, showed a higher proportion of nuclei with three AgNOR dots, a larger total area of dots in the nuclei, and a higher standard deviation of the AgNOR dot area in the nucleus. Adenomas immunopositive for prolactin, when compared with immunonegative ones, showed a larger mean area of the AgNOR dot, a larger area of the biggest dot in the nucleus, and a higher proportion of nuclei within a single dot. These results suggest that the estimated parameters of AgNOR dots differ according to tumor aggressiveness and to the hormone immunopositivity of pituitary adenomas.     

Quaternion-based strap-down integration method for applications of inertial sensing to gait analysis

The proposed strap-down integration method exploits the cyclical nature of human gait: during the gait swing phase, the quaternion-based attitude representation is integrated using a gyroscope from initial conditions that are determined during stance by an accelerometer. Positioning requires double time integration of the gravity-compensated accelerometer signals during swing. An interpolation technique applied to attitude quaternions was developed to improve the accuracy of orientation and positioning estimates by accounting for the effect of sensor bias and scale factor drifts. A simulation environment was developed for the analysis and testing of the proposed algorithm on a synthetic movement trajectory. The aim was to define the true attitude and positioning used in the computation of estimation errors. By thermal modelling, the changes of bias and scale factor of the inertial sensors, calibrated at a single reference temperature, were analysed over a range of ±10°C, for measurement noise standard deviations up to σ_g = 2.5° s⁻¹ (gyroscope) and σ_a = 0.05 m s⁻¹ (accelerometer). The compensation technique reduced the maximum root mean square errors (RMSEs) to: RMSE_θ=14.6° (orientation) and RMSE_d=17.7 cm (positioning) for an integration interval of one gait cycle (an improvement of 3° and 7 cm); RMSE_θ=14.8° and RMSE_d=30.0 cm for an integration interval of two gait cycles (an improvement of 11° and 262 cm).     

Predicting Skull Loading: Applying Multibody Dynamics Analysis to a Macaque Skull

Evaluating stress and strain fields in anatomical structures is a way to test hypotheses that relate specific features of facial and skeletal morphology to mechanical loading. Engineering techniques such as finite element analysis are now commonly used to calculate stress and strain fields, but if we are to fully accept these methods we must be confident that the applied loading regimens are reasonable. Multibody dynamics analysis (MDA) is a relatively new three dimensional computer modeling technique that can be used to apply varying muscle forces to predict joint and bite forces during static and dynamic motions. The method ensures that equilibrium of the structure is maintained at all times, even for complex statically indeterminate problems, eliminating nonphysiological constraint conditions often seen with other approaches. This study describes the novel use of MDA to investigate the influence of different muscle representations on a macaque skull model (Macaca fascicularis), where muscle groups were represented by either a single, multiple, or wrapped muscle fibers. The impact of varying muscle representation on stress fields was assessed through additional finite element simulations. The MDA models highlighted that muscle forces varied with gape and that forces within individual muscle groups also varied; for example, the anterior strands of the superficial masseter were loaded to a greater extent than the posterior strands. The direction of the muscle force was altered when temporalis muscle wrapping was modeled, and was coupled with compressive contact forces applied to the frontal, parietal and temporal bones of the cranium during biting. Anat Rec, 291:491–501, 2008. © 2008 Wiley‐Liss, Inc.     

Combined finite element and multibody dynamics analysis of biting in a Uromastyx hardwickii lizard skull

Lizard skulls vary greatly in shape and construction, and radical changes in skull form during evolution have made this an intriguing subject of research. The mechanics of feeding have surely been affected by this change in skull form, but whether this is the driving force behind the change is the underlying question that we are aiming to address in a programme of research. Here we have implemented a combined finite element analysis (FEA) and multibody dynamics analysis (MDA) to assess skull biomechanics during biting. A skull of Uromastyx hardwickii was assessed in the present study, where loading data (such as muscle force, bite force and joint reaction) for a biting cycle were obtained from an MDA and applied to load a finite element model. Fifty load steps corresponding to bilateral biting towards the front, middle and back of the dentition were implemented. Our results show the importance of performing MDA as a preliminary step to FEA, and provide an insight into the variation of stress during biting. Our findings show that higher stress occurs in regions where cranial sutures are located in functioning skulls, and as such support the hypothesis that sutures may play a pivotal role in relieving stress and producing a more uniform pattern of stress distribution across the skull. Additionally, we demonstrate how varying bite point affects stress distributions and relate stress distributions to the evolution of metakinesis in the amniote skull.     

Spatiotemporal analysis of event-related potentials to upright, inverted, and contrast-reversed faces: effects on encoding and recognition

In an n-back face recognition task where subjects responded to repeated stimuli, ERPs were recorded to upright, inverted, and contrast-reversed faces. The effects of inversion and contrast reversal on face encoding and recognition were investigated using the multivariate spatiotemporal partial least squares (PLS) analysis. The configural manipulations affected early processing (100-200 ms) at posterior sites: Inversion effects were parietal and lateral, whereas contrast-reversal effects were more occipital and medial, suggesting different underlying generators. A later reactivation of face processing areas was unique to inverted faces, likely due to processing difficulties. PLS also indicated that the "old-new" repetition effect was maximal for upright faces and likely involved frontotemporal areas. Marked processing differences between inverted and contrast-reversed faces were seen, but these effects were similar at encoding and recognition.     

Molecular genetics of pseudoxanthoma elasticum: type and frequency of mutations in ABCC6

Pseudoxanthoma elasticum (PXE) is a systemic heritable disorder that affects the elastic tissue in the skin, eye, and cardiovascular system. Mutations in the ABCC6 gene cause PXE. We performed a mutation screen in ABCC6 using haplotype analysis in conjunction with direct sequencing to achieve a mutation detection rate of 97%. This screen consisted of 170 PXE chromosomes in 81 families, and detected 59 distinct mutations (32 missense, eight nonsense, and six likely splice-site point mutations; one small insertion; and seven small and five large deletions). Forty-three of these mutations are novel variants, which increases the total number of PXE mutations to 121. While most mutations are rare, three nonsense mutations, a splice donor site mutation, and the large deletion comprising exons 23-29 (c.2996_4208del) were identified as relatively frequent PXE mutations at 26%, 5%, 3.5%, 3%, and 11%, respectively. Chromosomal haplotyping with two proximal and two distal polymorphic markers flanking ABCC6 demonstrated that most chromosomes that carry these relatively frequent PXE mutations have related haplotypes specific for these mutations, which suggests that these chromosomes originate from single founder mutations. The types of mutations found support loss-of-function as the molecular mechanism for the PXE phenotype. In 76 of the 81 families, the affected individuals were either homozygous for the same mutation or compound heterozygous for two mutations. In the remaining five families with one uncovered mutation, affected showed allelic compound heterozygosity for the cosegregating PXE haplotype. This demonstrates pseudo-dominance as the relevant inheritance mechanism, since disease transmission to the next generation always requires one mutant allelic variant from each parent. In contrast to other previous clinical and molecular claims, our results show evidence only for recessive PXE. This has profound consequences for the genetic counseling of families with PXE.