1,721,146 research outputs found
Acetabular index is the best predictor of late residual acetabular dysplasia after closed reduction in DDH
No full textRisk factors for the development of avascular necrosis after femoral neck fractures inchildren: a review of 239 OP-079 cases
No full textModeling of flexible metal wheel for pressurized lunar rover and traction performance prediction
No full textThe pressurized lunar rover has become one of the most important equipment in lunar exploration and resource utilization missions. On the terrain of soft lunar regolith, the rover wheels are easy to slip, sink, or even fail to move. To improve the traction performance of the rover on soft lunar soil, it is necessary to study the interaction between the wheels and the lunar soil. The deformation of the flexible wheel provides a larger contact area, which results in greater tractive force. Moreover, flexible wheels have better comfort and stability than rigid wheels, which are needed for manned rovers. However, there are few studies on the wheel soil interaction model of the heavy flexible wheel for the pressurized lunar rover. In this paper, a metal flexible wheel soil interaction model for pressurized lunar rovers was established, and the traction performance of the flexible wheel was predicted by using this model. Then, the accuracy of the wheel soil interaction model was verified by the soil bin test. The experimental results showed that the average error between the theoretical value of sinkage and the experimental value was 13.9%, and the average error between the theoretical and experimental value of drawbar pull was 11.5%, indicating that the model has high prediction accuracy. The new model can be used to predict the traction performance of flexible wheels and the experimental results can provide a reference for the flexible wheel design lunar rovers.</p
Optical and electrical properties of Y2O3 thin films prepared by ion beam assisted deposition
Full text link
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
DDH in the Walking Age: Review of Patients with Long-Term Follow-Up
No full textIntroduction The best treatment option in children with late detected DDH is still a subject of much controversy and only
few studies have investigated the long-term outcome of treatment in such patients. We performed a systematic review to assess long-term outcome of late detected DDH hips treated after walking age.
Methods Studies met inclusion criteria if they: (1) reported at least 30 hips treated; (2) included children aged between
9 months and 12 years; (3) treatment indication was late detected DDH after walking age; (4) presented a minimum followup of 10 years; (5) reported a clinical or radiological outcome. The Kaplan–Meier method was used to evaluate long-term survival according to clinical and radiological outcomes. The rate of total hip replacement (THR) was retrieved.
Results From a total of 6561 articles, 13 articles with grade IV level of evidence were included in our review. A total of 988 hips in 800 patients with a mean follow-up of 27.9 years (range 10–67) were included. The mean age at surgery was 3.3 years (range, 9 months–12 years). The rate of THR increased according to the length of inal follow-up. In particular, all studies reported no case of THR at 23.5 years of follow-up, a rate of 10.2% of THR between 30 and 40 years of follow-up and a rate of 35.6% of THR in patients with follow-up more than 40 years.
Conclusions In patients with late detected DDH, most THR became necessary more than 30 years after the index procedure
and their number increased further after 40 years and more of follow-up. Late detected DDH diagnosed after walking age
is a life-long disease
Closed reduction and dynamic cast immobilization in patients with developmental dysplasia of the hip between 6 and 24 months of age
No full textBackground Closed reduction and spica cast is still the preferred treatment option for children presenting with developmental
dysplasia of the hip (DDH) after the age of 6 months. This study aims to investigate the outcomes of patients with DDH
treated by closed reduction and dynamic cast immobilization.
Methods In total, 159 patients (mean age 15.6 ± 4.2 months; 172 hips) were treated with a dynamic cast immobilization for
3 months, followed by an abduction brace until a stable concentric reduction was achieved. Radiological examination was
performed at each follow-up visit to assess reduction, redislocation rate and presence of avascular necrosis (AVN) of the
femoral epiphysis. Final radiographic results were evaluated with the Severin classiication.
Results The redislocation rate was 4.1% (7/172); the overall AVN rate was 14.5% (grade II: 16 hips; grade III: 5 hips;
grade IV: 3 hips). At last follow-up visit, the mean age of patients was 61.6 ± 21.3 months (range 30.8–141), and the mean
acetabular index was 22.6° ± 5.6°; 67.3% of the hips had Severin type I radiographic criteria, 8.5% had type II, 23.6% had
type III, and 0.6% had type IV.
Conclusions Dynamic cast is an alternative to spica cast immobilization in DDH patients undergoing closed reduction. It
has similar redislocation and AVN rates compared to standard spica cast immobilization, as reported by previous studies
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
