中药复方对免疫损伤性肝纤维化大鼠肝损害的疗效观察

目的:研究中药复方方剂对免疫损伤性肝纤维化大鼠肝损害的治疗作用.方法:给大鼠腹腔注射猪血清,制备肝纤维化模型,以低剂量、高剂量中药复方颗粒治疗,测定治疗前后的ALT、A、G、A/G和PT,结合肝组织切片及细胞化学染色观察判断疗效.结果:与正常对照组比较,模型组ALT显著升高(P<0.001),A/G比值显著低于正常组(P<0.05);血浆凝血酶原时间(PT)明显延长(P<0.0005);肝纤维化明显;胶原纤维密度、巨噬细胞和储脂细胞显著高于正常组(P<0.05).治疗组一般状态良好,高、低剂量治疗组ALT(0.01相似文献   

Exploring opportunities available and perceived barriers to physical activity engagement in children and young people with Down syndrome

Primary objective: The aim of this study was to explore physical activity (PA) amongst children and young people with Down syndrome (DS). Method and procedures: The youth physical activity promotion model (YPAP) was used to inform semi-structured interviews to explore PA of children and young people with DS. Participants were three males and five females, aged between 6 and 21?years (16.38?+?5.04?years (mean?+?SD)) who had been diagnosed with the condition DS. Dyadic interviews were conducted with the participant and their parent(s). The interviews were recorded and transcribed, and inductive and deductive analyses of the data were completed. Main outcomes and results: The results were structured around the YPAP Model’s key themes included: enabling factors (seasonal variation, transport, type of activity and independence); predisposing factors (enjoyment, social interaction, dislikes of PA, following instructions, and understanding of PA); reinforcing factors (support and opportunities, parents, and care providers); and barriers to PA engagement (ear problems). Conclusion: The children and young people with DS in the study typically only engaged in fun, unstructured activities. Key facilitators for PA participation were social interactions and parental support. Increasing the level of independence for people with DS within adolescence may have beneficial effects for PA participation in later life.     

一种快速的自适应预失真算法

研究了一种快速有效的算法用来加快预失真算法的收敛速度,即线性迭代法。并通过计算机仿真来验证这种方法的有效性和可行性,通过计算机的仿真可以使三阶交调分量抑制大概15个dB。理论分析和仿真结果可以表明,该算法使功率放大器的线性化得到很好的改善。     

Help seeking in elementary classrooms: An observational study

This study was undertaken to explore how elementary school children employ help seeking as a means of problem solving in the classroom. In-depth naturalistic observations were made of high-, average-, and low-ability students in reading and math classes at the first-, third-, and fifth-grade levels. Overall, children's rates of help seeking were higher in math than in reading. Boys and girls did not differ overall in the amount of help sought. Boys and girls did differ, however, in the type of help they requested. Children of different ability levels were found to vary not only in rate of help seeking and type of help requested, but also in the type of responses elicited from their helper choices. Implications of these findings for children's achievement, learning, and social adjustment in the classroom are discussed.     

Patterns of interdependence in cooperative work of elementary children

Following a theoretical analysis of factors which foster interpersonal cooperation, this study explored conditions conducive to school children's working together harmoniously and productively. Seventy-six like-sexed triads of fourth- and fifth-graders were asked to cooperate in making a block picture on a round board. Five conditions were created, varying in patterns of interdependence. All conditions included goal interdependence; they differed systematically in the presence of task requirements, task roles, and group roles. Behavior was precoded into various group oriented and individual oriented categories. An index of quality of performance was constructed. As hypothesized, while goal interdependence was sufficient to bring about friendly interactions, it did not maximize occurrence of group oriented behavior. Children worked together most, and performance was significantly better, under conditions where taks requirements, task roles, and group roles were present together. A strong consistent pattern of sex differences was found, with boys showing greater independence from experimental role inductions than did the girls, whose cooperative work pattern and performance increased systematically as their interdependence was strengthened in the five conditions. Implications for instructional practice are examined.     

The Concept of Intellectual Level in Cataloging and Classification

This paper traces the history of the concept of intellectual level in cataloging and classification in the United States. Past cataloging codes, subject-heading practice, and classification systems have provided library users with little systematic information concerning the intellectual level or intended audience of works. Reasons for this omission are discussed, and arguments are developed to show that this kind of information would be a useful addition to the catalog record of the present and the future.     

Determining motions with an IMU during level walking and slope and stair walking

ABSTRACT

This study investigated whether using an inertial measurement unit (IMU) can identify different walking conditions, including level walking (LW), descent (DC) and ascent (AC) slope walking as well as downstairs (DS) and upstairs (US) walking. Thirty healthy participants performed walking under five conditions. The IMU was stabilised on the exterior of the left shoe. The data from IMU were used to establish a customised prediction model by cut point and a prediction model by using deep learning method. The accuracy of both prediction models was evaluated. The customised prediction model combining the angular velocity of dorsi–plantar flexion in the heel-strike (HS) and toe-off (TO) phases can distinctly determine real conditions during DC and AC slope, DS, and LW (accuracy: 86.7–96.7%) except for US walking (accuracy: 60.0%). The prediction model established by deep learning using the data of three-axis acceleration and three-axis gyroscopes can also distinctly identify DS, US, and LW with 90.2–90.7% accuracy and 84.8% and 82.4% accuracy for DC and AC slope walking, respectively. In conclusion, inertial measurement units can be used to identify walking patterns under different conditions such as slopes and stairs with customised prediction model and deep learning prediction model.     

Factors related to third grade achievement: Self-perception,classroom composition,sex, and race

The purpose of this research was to investigate the relationship between self-perception and academic achievement among third grade black and white disadvantaged school children. Race, sex, IQ, self-perception, and student's perceptions of their teacher's perceptions were examined as sources of variance in academic achievement. Data from one-hundred-sixteen students were analyzed by means of stepwise multiple regression. Results suggest that self-perceptions account for more variance in academic achievement for students who are of the same sex and race as the teacher than for those who are not. Self-perceptions of black students in all black classrooms account for more variance in respect to achievement than do self-perceptions of black students in integrated classrooms.     

PA241DW在压电陶瓷挤压光纤型偏振稳定器中的应用

挤压光纤可以改变光纤中传输光的偏振态，基于此研制了压电陶瓷（piezoelectric ceramic,PZT）挤压光纤型偏振稳定器。PZT驱动电源是偏振稳定器中的关键部件，对偏振稳定器的各项性能有很大影响。文章利用高压运算放大器PA241DW设计出一种PZT驱动电源，相对于目前常用驱动电源具有精度高、响应快、电路简明和价格低廉的特点。