Intraoperative application of three-dimensional printed guides in total hip arthroplasty: A systematic review

BACKGROUND Acetabular component positioning in total hip arthroplasty(THA)is of key importance to ensure satisfactory post-operative outcomes and to minimize the risk of complications.The majority of acetabular components are aligned freehand,without the use of navigation methods.Patient specific instruments(PSI)and three-dimensional(3D)printing of THA placement guides are increasingly used in primary THA to ensure optimal positioning.AIM To summarize the literature on 3D printing in THA and how they improve acetabular component alignment.METHODS PubMed was used to identify and access scientific studies reporting on different 3D printing methods used in THA.Eight studies with 236 hips in 228 patients were included.The studies could be divided into two main categories;3D printed models and 3D printed guides.RESULTS 3D printing in THA helped improve preoperative cup size planning and post-operative Harris hip scores between intervention and control groups(P=0.019,P=0.009).Otherwise,outcome measures were heterogeneous and thus difficult to compare.The overarching consensus between the studies is that the use of 3D guidance tools can assist in improving THA cup positioning and reduce the need for revision THA and the associated costs.CONCLUSION The implementation of 3D printing and PSI for primary THA can significantly improve the positioning accuracy of the acetabular cup component and reduce the number of complications caused by malpositioning.

利用LibGuides创建高校图书馆数字化阅读推广平台的探索与实践

目的:以北京工商大学图书馆为例,探讨将Lib Guides平台用于阅读推广工作的尝试,旨在与同行分享经验和心得,为高校图书馆更好地利用Lib Guides平台进行阅读推广工作提供借鉴。方法:调研Lib Guides平台在国内外的应用现状及国内高校图书馆数字化阅读推广工作现状,比较了3种数字化阅读推广工作的优势和不足,指出利用Lib Guides平台进行阅读推广的优势。结论:Lib Guides具有后台管理灵活、组织层次清晰、界面外观统一、用户交互性强等优点,高校图书馆可以利用它创建数字化阅读推广平台,开展阅读推广工作。

Theoretical Analysis and Numerical Simulation of the Static and Dynamic Characteristics of Hydrostatic Guides Based on Progressive Mengen Flow Controller

The oil film thickness of oil hydrostatic guide with constant pressure supply based on capillary restrictor is greatly affected by load, and this kind of hydrostatic guide is usually applied to the machine tools with moderate load. The static and dynamic characteristics of the guide have been studied by using some theoretical, numerical and experimental approaches, and some methods and measures have been proposed to improve its performances. The hydrostatic guide based on progressive mengen（PM） flow controller is especially suitable for the heavy numerical control（NC） machine tools. However, few literatures about the research on the static and dynamic characteristics of the hydrostatic guides based on PM flow controller are reported. In this paper, the formulae are derived for analyzing the static and dynamic characteristics of hydrostatic guides with rectangle pockets and PM flow controller according to the theory of hydrostatic bearing. On the basis of the analysis of hydrostatic bearing with circular pocket, some equations are derived for solving the static pressure, volume pressure and squeezing pressure which influence the dynamic characteristics of hydrostatic guides with rectangle pocket. The function and the influencing factors of three pressures are clarified. The formulae of amplitude-frequency characteristics and dynamic stiffness of the hydrostatic guide system are derived. With the help of software MATLAB, programs are coded with C＋＋ language to simulate numerically the static and dynamic characteristics of the hydrostatic guide based on PM flow controller. The simulation results indicate that the sensitive oil volume between the outlet of the PM flow controller and the guide pocket has the greatest influence on the characteristics of the guide, and it should be reduced as small as possible when the field working condition is met. Choosing the oil with a greater viscosity is also helpful in improving the dynamic performance of hydrostatic guides. The research work has instructing significance for analyzing and designing the guide with PM flow controller.

Patient specific guides for total knee arthroplasty are ready for primetime

AIM: To present the radiological results of total knee arthroplasty(TKA) with use of patient specific matched guides(PSG) from different manufacturer in patients suffering from severe osteoarthritis of the knee joint.METHODS: This study describes the results of 57 knees operated with 4 different PSG systems and a group operated with conventional instrumentation(n = 60) by a single surgeon. The PSG systems were compared with each other and subdivided into cut- and pin PSG. The biomechanical axis [hip-knee-ankle angle(HKA)], varus/valgus of the femur [frontal femoral component(FFC)] and tibia(frontal tibial component) component, flexion/extension of the femur [flexion/extension of the femur component(LFC)] and posterior slope of the tibia [lateral tibial component(LTC)] component were evaluated on long-leg standing and lateral X-rays. A percentage of > 3° deviation was seen as an outlier. RESULTS: The inter class correlation coefficient(ICC) revealed that radiographic measurements between both assessors were reliable(ICC > 0.8). Fisher exact test was used to test differences of proportions. The percentage of outliers of the HKA-axis was comparable between both the PSG and conventional groups(12.28% vs 18.33%, P < 0.424) and the cut- and pin PSG groups(14.3% vs 10.3%, P < 1.00). The percentage of outliers of the FFC(0% vs 18.33%, P < 0.000), LFC(15.78% vs 58.33%, P < 0.000) and LTC(15.78% vs 41.67%, P < 0.033) were significant different in favour of the PSGgroup. There were no significant differences regarding the outliers between the individual PSG systems and the PSG group subdivided into cut- and pin PSG.CONCLUSION: PSG for TKA show significant less outliers compared to the conventional technique. These single surgeon results suggest that PSG are ready for primetime.

Gene expression profiles of human adipose-derived mesenchymal stem cells dynamically seeded on clinically available processed nerve allografts and collagen nerve guides

It was hypothesized that mesenchymal stem cells(MSCs) could provide necessary trophic factors when seeded onto the surfaces of commonly used nerve graft substitutes. We aimed to determine the gene expression of MSCs when influenced by Avance■ Nerve Grafts or Neura Gen■ Nerve Guides. Human adipose-derived MSCs were cultured and dynamically seeded onto 30 Avance■ Nerve Grafts and 30 Neura Gen■ Nerve Guides for 12 hours. At six time points after seeding, quantitative polymerase chain reaction analyses were performed for five samples per group. Neurotrophic [nerve growth factor(NGF), glial cell line-derived neurotrophic factor(GDNF), pleiotrophin(PTN), growth associated protein 43(GAP43) and brain-derived neurotrophic factor(BDNF)], myelination [peripheral myelin protein 22(PMP22) and myelin protein zero(MPZ)], angiogenic [platelet endothelial cell adhesion molecule 1(PECAM1/CD31) and vascular endothelial cell growth factor alpha(VEGFA)], extracellular matrix(ECM) [collagen type alpha I(COL1A1), collagen type alpha III(COL3A1), Fibulin 1(FBLN1) and laminin subunit beta 2(LAMB2)] and cell surface marker cluster of differentiation 96(CD96) gene expression was quantified. Unseeded Avance■ Nerve Grafts and Neura Gen■ Nerve Guides were used to evaluate the baseline gene expression, and unseeded MSCs provided the baseline gene expression of MSCs. The interaction of MSCs with the Avance■ Nerve Grafts led to a short-term upregulation of neurotrophic(NGF, GDNF and BDNF), myelination(PMP22 and MPZ) and angiogenic genes(CD31 and VEGFA) and a long-term upregulation of BDNF, VEGFA and COL1A1. The interaction between MSCs and the Neura Gen■ Nerve Guide led to short term upregulation of neurotrophic(NGF, GDNF and BDNF) myelination(PMP22 and MPZ), angiogenic(CD31 and VEGFA), ECM(COL1A1) and cell surface(CD96) genes and long-term upregulation of neurotrophic(GDNF and BDNF), angiogenic(CD31 and VEGFA), ECM genes(COL1A1, COL3A1, and FBLN1) and cell surface(CD96) genes. Analysis demonstrated MSCs seeded onto Neura Gen■ Nerve Guides expressed significantly higher levels of neurotrophic(PTN), angiogenic(VEGFA) and ECM(COL3A1, FBLN1) genes in the long term period compared to MSCs seeded onto Avance■ Nerve Grafts. Overall, the interaction between human MSCs and both nerve graft substitutes resulted in a significant upregulation of the expression of numerous genes important for nerve regeneration over time. The in vitro interaction of MSCs with the Neura Gen■ Nerve Guide was more pronounced, particularly in the long term period(> 14 days after seeding). These results suggest that MSC-seeding has potential to be applied in a clinical setting, which needs to be confirmed in future in vitro and in vivo research.

Constructing Teaching Model for Training English Guides of Stone Inscription Relics

A teaching model based on constructivism is proposed in this paper. The model contains five teaching steps, e.g. interpretation teaching, questioning- dialogue, knowledge and skills teaching, discussion- collaboration and field training. Practice proves that it can effectively improve the training efficiency of the training of English guides of stone inscription relics and enhance their interpretation quality and English skills.

Weakly Guiding Fibers and LP Modes in Circular and Elliptical Waveguides

This paper gives the simple and logical approach of LP modes in circular and elliptical waveguides. Earlier the basic approach of modes in circular and elliptical fibers was studied by the authors. In this paper, the role of radial antinode in circular and elliptical waveguides is given clearly. Splitting of modes in circular and elliptical fiber has been discussed.

Generic Framework for Context-Aware Communication Services in Visitor’s Guides

Ubiquitous computing plays an increasing role in our lives. Typically, applications in ubiquitous computing environ-ments are context aware, namely, they react to the situations of their users at a given moment in time. One example for such environment is visitor’s guides in cultural heritage sites, supporting visits of individuals or small groups, such as families or friends. In such environments, it is well known that interaction among visitors enhances the overall visit experience. Recently, some research prototypes of visitor’s guides have started supporting such interaction through textual communication services embedded in them. However, these applications have so far been developed separately in an ad-hoc manner, despite common features and infrastructures they share. The research described here generalizes communication services offered by different visitor’s guides and suggests a systematic and generic framework for developing context-aware communication services for visitor’s guides. The specific communication services are abstracted into a domain model, later used in practice for adapting and tailoring the different concepts to the specific requirements of the applications. The framework is demonstrated in the specific setting of a multi-agent museum visitor’s guide system. We also show that the suggested framework is not limited to the specific museum visitor’s guide system but may facilitate the development of context-aware communication applications in general.

Innovation Guides the Global Household Electrical Appliance Industry——an exclusive interview with Haier's Vice-president, Yu Zida

As we know, PACT (President's Advisory Committee on Future Technology) members of the IEC (International Electrotechnical Commission) used to be CTOs of large companies from only a few developed countries such as the United States, Germany and Japan. However, Haier Group has broken the ice since it entered the IEC/PACT commission in June 2005, lifting the curtain on international standardization of our national enterprises. And now, Haier is hosting the IEC/PACT annual conference in November 2007. Could you introduce it in detail?

A Study on the C-E Translation of Travel Guides of Henan Scenic Spots from the Perspective of Skopostheory

Travel guides are not only important windows for foreign visitors to obtain information on China's scenic spots, but also main mediums for spreading Chinese culture. By comparing and analyzing the differences between Chinese and English travel guides, this paper, combined with the case of Henan scenic spots, makes a study of the translation principle, translation strategy and translation methods of travel guides from the perspective of Skopostheory.

A review of crosstalk research for plasmonic waveguides

Plasmonic waveguides,as a competitive candidate,have been widely studied in rapid developing photonic integrated circuits(PICs)and optical interconnection fields.However,crosstalk between plasmonic waveguides is a critical issue that has to be considered in practice.Actually,crosstalk dominates the ultimate integration density of the planar photonic circuits.This paper reviews the recent research work on evaluation methods and crosstalk suppression approaches of plasmonic waveguides.Three crosstalk evaluation methods based on comparison of specific parameters of waveguides have been summarized.Furthermore,four specific approaches to reduce crosstalk have been illustrated as two categories according to their impacts on waveguide performances and the whole circuit.One means of crosstalk suppression is changing the placement of waveguides,which could maintain the transmission characteristics of the original waveguide.The other means is inserting medium,which has the advantage of occupying smaller space compared to the first method.Consequently,to suppress crosstalk between plasmonic waveguides,one should choose suitable approach.

Tour Guides and Destination Image： Evidence From Portugal

Tourist guides as front-line professionals, information-givers, and interpreters act as destination representatives and ＂ambassadors＂ in the eyes of tourists （Raboti6, 2010）. This paper, using an empirical analysis of coach tour foreign tourists travelling in Portugal, intends to determine how tourist destination image （TDI） is modified and enhanced through the influence of tourist guide performance and tourist satisfaction with the guided tour. A survey questionnaire of first-time package tour travellers to Portugal revealed a positive change in attitude to image components such as monuments/museums, tourist information, landscape, and gastronomy and wines, confirming that the tourist guide＇s attributes in communication skills and scholar knowledge （history, art, and popular culture） together with highly rated tourist satisfaction with the guided tour concerning the professional competence of a bus driver were critical in enhancing Portugal destination image. Marketing implications for senior coach tour in Portugal are drawn.

Effects of Tour Guides Training on Their Performance in Kenya

It is important for a completive tourism destination to ensure that tourists get the company of a professional tour guide who guides and interprets attraction in the areas visited. Undefined level of education, lack of standardized training curriculum, and lack of barrier to the guiding career have affected the performance of tour guides in Kenya. Limited research in Kenya has been conducted to establish the role of guides in satisfying customer and protecting the environment. The study objective was to examine tour guides＇ interpretation knowledge and their opinion on areas that require more training so as to improve their performance. The study hypothesized that tour guides＇ opinions on their training needs are independent on the level of education, work experience and qualification. It is hypothesized that guides require additional training in flora and fauna of East Africa, cultural heritage and customer service. They require training in ICT （Information Communications Technology）, eco-tourism principles, and at least one foreign language. The study hypothesizes that the higher the level of a guide＇s training, the more resourceful the guide will be. The study used qualitative and quantitative research approaches where questionnaires, interviews and focus groups discussion （FGDs） were used to collect the primary data. The finding shows that tour guides＇ opinions on areas they require further training were independent of their highest level of education, work experience and qualification. Most guides irrespective of their level of education, work experience and qualifications were of the opinion that they needed more training on mammals and plants （χ^2 = 1.07, df= 2, P = 0.583）, training on birds and insects （χ^2 = 0.254, df= 2, P = 0.885） and training on culture and history of East Africa （χ^2 = 1.140, df= 2, P = 0.566）. Respondents＇ training needs were independent on the duration of tour guiding course training had taken. Guides trained for less than six months, one year and more than two years agreed that training on foreign language （χ^2 = 4.84, df = 2, P = 0.196）, ecotourism principles （χ^2 = 1.62, df = 2, P = 0.653） and tour planning and costing （χ^2 = 399, df = 3, P = 0.262） would improve their performance. The study concludes that tour guides are aware of the areas that they need to be trained and should be consulted before organizing such training. They require more training irrespective of their level of education, certification and work experience. The study recommends tour guide curriculum be standardized and all guides should sit for an exam before they are licensed to guide and only those with such license be allowed to practice guiding.

Broadband Fluorescence Guided-Wave in DANS/PMMA Thin Film Waveguides

The broadband fluorescence guided-waves excited in DANS/PMMA polymer thin film waveguides by an Ar+laser beam were demonstrated in terms of the observation of mlines with colour array.Considering the high brightness of these m-lines observation,we assert that it is a kind of stimulated amplification of fluorescence guided-wave.

Experimental study of Internet telerobotics based on virtual guides

For the virtual environment (VE) to control remote robots through Internet, this paper proposes an operational idea based on virtual guides (VGs). The VGs consist of three types, line VG, plane VG, and body VG, which can greatly enhance the safety and flexibility of the man-machine system. Through the analysis of several common cases, the idea of the VGs are first introduced and described. Second, detailed descriptions of the three VGs are given, and then a uniform representation of all VGs is given. Finally, a typical experiment is designed and implemented according to the modes of video feedback, video&VE feedback, and video&VE&VG feedback. Experimental results show that the operation based on VEs and VGs have significant advantages over that based on video feedback, and VGs can greatly improve the ability of the VE to control remote robots, thus obtaining high and efficient man-machine cooperation.

EFFECT OF THE GUIDES ON THE LOWEST CRITICAL ROTATIONAL FREQUENCIES OF CIRCULAR SAW

The effects of the location,number and stiffness of guide pads on the lowest critical rotational frequencies of the rotating circular saw damped at the inside and free at the perimeter are discussed by the non linear theory and the perturbation theory of structural vibration analysis The influence of the centrifugal force and the cutting temperature are considered in the course of the analysis The results of the analysis and the calculation show that the introduction of one guide does not stably raise critical rotational frequencies of the circular saw The two guides can raise lowest critical rotational frequency of the circular saw when the angle between the two guides fixed on the direction of the circumference satisfies the certain conditions

Asymptotic Theory of Guided Modes for Cladded Slab Waveguides

Multilayer cladded slab waveguides have been solved by using asymptotic theory once or twice. Based on the solution of a three layer slab waveguide, the wave number of guided modes has been expanded in series of one or two small parameters. One side cladded slab, two side cladded slab and two parallel cladded slab waveguide system are demonstrated to show how to use this essentially analytic method. Numerical examples have also been given and compared with exact solutions, eved the first or second order solutions are highly accurate.

The Formation of the Image of Modern China in the West from the Perspective of Travel Guides

Since the Middle Ages,the collective memory of China in the West had been based on the texts written by peregrinators to China,represented by Marco Polo and the missionary community.After the 19^(th) century,travel guide,another form of text to guide potential peregrinators to China,began to appear.They selectively recorded and subjectively evaluated the landscape and life of China,with distinct individual characteristics,which had significant influence on the formation and dissemination of the image of China.

基于Guided BERTopic模型的产业链关键核心技术识别与发展趋势研判--以未来工业互联网为例

产业链关键核心技术不仅是国之重器,而且对推动我国经济的高质量发展和保障国家安全起着至关重要的作用。当前,工业互联网产业链的关键技术发展成为我国的研究重点,该领域的重要性在2023年被提升至国家级重大研究计划。综合收集了1989-2024年中美两国在工业互联网领域的专利数据,基于《关键和新兴技术清单》和《未来工业互联网基础理论与关键技术重大研究计划》,构建了一套工业互联网产业链核心关键技术的种子词库。利用Guided BERTopic模型提取了产业链关键技术主题,并采用Logistic模型评估了这些技术的生命周期,进而对比中美两国的发展情况,提出了针对未来发展的建议。研究结果表明,相比美国,我国在大多数产业链核心技术方面仍处于成长阶段,而美国则已步入技术饱和阶段。展望未来,设备监测系统、设备管理系统、无线通信技术及能耗监测分析系统等被认为是具有巨大发展潜力的技术。研究提出了一种基于政策文件的产业链关键技术识别方法,并通过对工业互联网专利技术的实证分析,为制定相关政策提供了科学指导和建议。

Study of Axisymmetric Infinite Guide Lined with Locally Reacting Material without Flow Using DtN Operators

The present work proposed a new method for the modeling by the finite element method of the acoustic propagation problems in infinite axisymmetric cylindrical guides lined with locally reacting absorbent materials without flow. The method deals with the development of an efficient transparent boundary condition based on DtN operators. The method developed in this study is successfully applied to a straight axisymmetric lined guide by imposing a mode on one of the artificial boundaries of the truncated guide. The results are in good agreement with analytical solutions. Applying the method for a non-uniform axisymmetric lined guide which is a complex case, proved its effectiveness and the results compared to those of PML layers are in very good agreement.