Matching Time Research Articles

Training and competition injury epidemiology in professional basketball players: a prospective observational study

ABSTRACT Background There is a lack of epidemiological data comparing the characteristics of injuries sustained during basketball matches vs. training taking into account incidence, type of injury, body location and risk factors associated with the development of the injury. Purpose The main aim of the present study was to analyze the incidence and characteristics of training vs. competition injuries sustained by professional basketball players. Methods The injuries incurred by 61 professional basketball players (mean ± SD, age: 25.7 ± 5.1 years; height: 200.2 ± 9.2 cm; body mass: 98.2 ± 13.8 kg) from the same team were prospectively recorded by the team’s medical staff for 6 consecutive seasons (2014/15 to 2019/20). The team competed in a top national basketball division and in the EuroLeague among other national-level competitions. The injuries were recorded using a validated medical questionnaire that included information according to type, severity, location, and injury mechanism. Training and match times were also recorded for each player in order to calculate injury incidence. Results A total of 306 injuries were reported, representing 12.59 injuries per 1000 h of basketball play. Most injuries occurred without direct contact with another player/object (70.9%) and were located in the lower limbs (74.8%), particularly in the knee (22.9%). The incidence of injuries was higher during competition than during training: 77.83 vs. 8.29 injuries per 1000 h of basketball play. However, there were no differences in the mechanism and mode of onset between training and competition injuries while the proportion of time-loss injuries was also similar in training and competition. Conclusions In summary, injury incidence in professional basketball was ~10-times higher during competition than during training. Beyond differences in incidence, injury characteristics were similar for basketball training and competition.

Long-standing pubic-related groin pain in professional academy soccer players: a prospective cohort study on possible risk factors, rehabilitation and return to play

BackgroundDespite being a common overuse entity in youth soccer, scientific data on risk factors, rehabilitation and return to play for long-standing pubic-related groin pain is still rare. The current prospective cohort study aims to evaluate potential risk-factors, propose a criteria-based conservative rehabilitation protocol and assess return-to-play outcomes among professional youth soccer players suffering from long-standing pubic-related groin pain.MethodsMale soccer players with long-standing (> 6 weeks) pubic-related groin pain from a professional soccer club’s youth academy were analyzed for possible risk factors such as age, team (U12 - U23), younger/older age group within the team, position and preinjury Functional movement score. All injured players received a conservative, standardized, supervised, criteria-based, 6-level rehabilitation program. Outcome measures included time to return to play, recurrent groin pain in the follow-up period and clinical results at final follow-up two years after their return to play.ResultsA total of 14 out of 189 players developed long-standing pubic-related groin pain in the 2017/2018 season (incidence 7.4%). The average age of the players at the time of the injury was 16.1 ± 1.9 years. Risk factor analysis revealed a significant influence of the age group within the team (p = .007). Only players in the younger age group were affected by long-standing pubic-related groin pain, mainly in the first part of the season. Injured players successfully returned to play after an average period of 135.3 ± 83.9 days. Only one player experienced a recurrence of nonspecific symptoms (7.1%) within the follow-up period. The outcome at the 24-month follow-up was excellent for all 14 players.ConclusionsLong-standing pubic-related groin pain is an overuse entity with a markedly high prevalence in youth soccer players, resulting in a relevant loss of time in training and match play. In particular, the youngest players in each team are at an elevated risk. Applying a criteria-based rehabilitation protocol resulted in an excellent return-to-play rate, with a very low probability of recurrence.Trial registrationThe trial was retrospectively registered under DRKS00016510 in the German Clinical Trials Register on 19.04.2021.

Abstract 10559: Association of Intra-Arrest Transport versus Continued On-scene Resuscitation with Survival to Hospital Discharge Among Pediatric Patients with Out-of-Hospital Cardiac Arrest

Introduction: For pediatric patients with out-of-hospital cardiac arrest (OHCA) who do not achieve return of spontaneous circulation (ROSC), it remains unclear whether patients should be transported to a hospital with ongoing resuscitation or remain on-scene for further resuscitation. We therefore evaluated: (1) the association between intra-arrest transport, with reference to continued on-scene resuscitation, and survival to hospital discharge; and, (2) whether the association differs across the timing of intra-arrest transport. Methods: We conducted a secondary analysis of the Resuscitation Outcomes Consortium Epidemiologic Registry. We included pediatrics (<18 years) with emergency medical services (EMS)-treated OHCA between 2005 and 2015. Our exposure of interest was intra-arrest transport, defined as transport to a hospital prior to ROSC. Patients who had intra-arrest transport at any minute after EMS arrival underwent risk-set matching with patients who had continued on-scene resuscitation within the same minute using time-dependent propensity score calculated from patient demographics, arrest characteristics, and EMS interventions. We repeated the main analysis with 5-minute strata by the time of matching. Results: Of 2,854 included patients, the median age was 1 year (IQR, 0-9), 59.3% were male, 9.8% were public location, 22.1% were bystander witnessed, 6.0% had initial shockable rhythms, and 66.3% underwent intra-arrest transport at a median of 15 minutes (IQR 9-22) after EMS arrival. In the propensity-matched cohort including 2,080 patients, 5.5 % (57/1040) in intra-arrest transport group and 5.9% (61/1040) in continued on-scene resuscitation group had survival to hospital discharge (risk ratio [RR]=0.94, 95% CI 0.65-1.37). We did not detect an association within the time-based strata: 0-5 minutes (RR=0.74, 95% CI 0.19-2.85), 5-10 minutes (RR=0.52, 95% CI 0.23-1.16), 10-15 minutes (RR=1.13, 95% CI 0.58-2.22), 15-20 minutes, (RR=1.70, 95% CI 0.78-3.71), or >20 minutes (RR=0.73, 95% CI 0.32-1.63) after EMS arrival. Conclusions: Among pediatric patients with OHCA, intra-arrest transport was not associated with survival to hospital discharge. The findings persisted across the timing of intra-arrest transport.

Improving Matching Accuracy of Underwater Gravity Matching Navigation Based on Iterative Optimal Annulus Point Method with a Novel Grid Topology

In this study, we improve the matching accuracy of underwater gravity matching navigation. Firstly, the Iterative Optimal Annulus Point (IOAP) method with a novel grid topology is proposed for breaking through the inherent grid structure limit of the canonical gravity matching algorithm and enhancing its underwater gravity matching accuracy. The theory of IOAP is as follows: (1) small-annulus matching and positioning mechanism on the tracking starting point is developed by employing the starting point and drift error of the INS (Inertial Navigation System), the fixed rotation angle, etc. The optimal matching location of the starting point is obtained by matching and comparing the matched points in this small-annulus grid, which contributes to heightening the initial-position error insensitivity of the algorithms. (2) Variable-angle three-layer annulus matching and positioning mechanisms on the tracking ending point were constructed by using the optimal matching location of the starting point and combining the tracking direction-and-distance information of the INS and the cumulative drift error, etc. It is used to generate the annulus matching points with the ring-type grid topology. (3) The optimal matching position of the ending point in this annulus is obtained by iteratively calculating the evaluation index value of the matching points and following the evaluation index optimal rule. Secondly, we comprehensively consider the main performance evaluation indexes of the underwater gravity matching algorithms, such as the statistical indicators of the matching accuracy, the average matching time and the matching success rate, and take them as a basis of the pros and cons of the matching analysis. Furthermore, under conditions that include different scale searching regions or different reference-angle ring radii, the statistical results verify that the IOAP had a different matching ability and better robustness. Finally, several trajectories with the starting points from different areas and the ending points in different gravity ranges are tested and compared to carry out the numerical simulations. These results indicate that the IOAP has many advantages, such as a high matching accuracy and strong positioning applicability in different gravity regions. Compared with the TERCOM (terrain contour matching algorithm), its average matching accuracy was the highest, increased by 40.39%.

Method for rapidly generating urban damage scenarios under non-uniform ground motion input based on matching algorithms and time history analyses

Due to the rapid urbanization, the built environment becomes more complex and denser, making cities especially vulnerable to strong earthquakes. It is important to simulate seismic disaster scenarios of buildings and critical infrastructures accurately in a reasonable time for the development of urban disaster prevention strategies and decision-making frameworks for post-earthquake emergence rescue. In this study, a novel methodology is established to rapidly generate detailed seismic disaster scenarios that virtually illustrate the damage distribution of buildings in city level without executing time history analysis. The non-uniform distribution of ground motions is taken into account for a large area. The large city is divided into small areas, and a scenario database is generated by performing massive nonlinear time history analyses through the city-level simulation platform recently developed by the authors. The proposed method selects and composes the best matching disaster scenarios by assessing the scenario database within a very short time using matching algorithms. Three matching algorithms, including the single wave matching algorithm, multiple waves splicing matching algorithm and multiple waves combination matching algorithm, are applied to form disaster scenario for any given input ground motion. The performance and effectiveness of the three matching algorithms are examined and a case study on simulation of a large city is presented. The results show that the matching algorithms are all feasible, and the multiple waves splicing matching algorithm is the most efficient. The proposed methodology not only produces reasonably similar results and findings to those obtained by the nonlinear time history analysis directly, but also can reduce the computing time by over 98%.

Non-Invasive Genetic Profiling and Monitoring in Myelodysplastic Syndromes

Introduction. Myelodysplastic syndromes (MDS) are clonal heterogeneous disorders in which molecular studies and cytogenetics are essential for diagnosis, classification and prognosis. Cell-free DNA (cfDNA) analysis has been reported as a reliable non-invasive approach for detecting molecular abnormalities in MDS. However, there is limited information about cytogenetic alterations and monitoring in cfDNA from MDS patients.Objective. To assess and monitor the molecular and cytogenetic abnormalities by next generation sequencing (NGS) using cfDNA from patients with MDS.Patients and methods. Bone marrow (BM) aspirates and peripheral blood (PB) samples were collected from 70 newly diagnosed or treatment-naïve patients with MDS (Table). PB samples from 21 healthy controls were also studied. Molecular characterization was performed in paired samples of BM DNA and cfDNA by NGS in all patients. Libraries were prepared using a custom panel including 48 myeloid-associated genes and genomic regions localized at the most frequently altered chromosomes in MDS (QIAseq Custom DNA Panels, Qiagen) and sequenced using Illumina. 20/70 (28.6%) showed cytogenetic/FISH alterations at diagnosis, 2 of them with infrequent alterations in MDS, not covered by the panel (+14, del(9q)). 6 cases presented chromosome Y loss as a single alteration, not covered by the NGS panel. Copy number variant (CNV) analysis was performed by NGS to detect cytogenetic alterations in both cfDNA and BM, and confirmed by chromosomal microarrays (CMA) in BM DNA (CytoScan/OncoScan, ThermoFisher).Results. We obtained a median amount of cfDNA of 58.4 ng/ml in MDS patients that was significantly higher than that obtained in healthy controls (median 32.4 ng/ml, P=0.023). Sequencing of BM DNA and cfDNA showed a comparable mutational profile (187/201 mutations, 93.0% concordance). The most frequently mutated genes were TET2 (44.3%), SF3B1 (37.1%), ASXL1 (20.0%), DNMT3A (20.0%), SRSF2 (15.7%), ZRSR2 (12.9%) and U2AF1 (12.9%). A strong correlation was observed between the VAFs of BM DNA and cfDNA (r s=0.797, P<0.001). VAFs of SF3B1 mutations detected in cfDNA were significantly higher than VAFs in BM DNA (P=0.016).The analysis of cytogenetic alterations by NGS showed abnormalities in 10/70 MDS patients in both BM DNA and cfDNA. Interestingly, in a patient without analyzable metaphases in karyotype, del(20q) was found by NGS and confirmed by CMA. Overall, CMA and NGS were highly concordant to detect chromosomal aberrations although they do not reach the sensitivity achieved by karyotype/FISH (Figure 1). However, all cytogenetic aberrations detected by NGS in BM DNA were also detected in cfDNA.Molecular and cytogenetic alterations were monitored in sequential samples from 7 cases (median follow up: 13 months, range 10-30). We observed an excellent correlation between the VAF of mutations in BM DNA and ctDNA across multiple matched time points. A decrease in the VAF was detected in patients responding to therapy (either hypomethylating agents or chemotherapy), but not in non-responding patients (Figure 2). Of note, cfDNA analysis also showed cytogenetic evolution in 2 cases not responding to azacitidine (del(12p) and +21). From the two untreated patients, one acquired a subclonal del(7q) not detected by NGS and observed only in few metaphases, and the second patient showed a clonal expansion of the NF1 mutation at the time of AML transformation.Conclusions. Analysis of cfDNA allows the characterization and monitoring of molecular abnormalities in patients with MDS. Cytogenetic alterations were detectable in most cases by NGS in both BM DNA and cfDNA although with a lower detection rate than karyotype/FISH.Acknowledgements. ISCIII-FEDER, PI16/0153, PI19/0005, 2017SGR205, PT20/00023 and XBTC.Figure/Table legends:Table. MDS patients included, classified by disease subtype. (SLD: single lineage dysplasia; MLD: multilineage dysplasia; RS: ring sideroblasts; EB: excess blasts; MDS-U: MDS-unclassifiable)Figure 1. Detection of cytogenetic alterations by conventional karyotype, FISH, CMA and NGS.Figure 2. Monitoring of molecular and cytogenetic alterations in 7 patients with MDS. 5 patients receiving treatment (3 azacitidine, 1 FLAG-IDA + HCT, 1 inhibitor of hypoxia-inducible factor (HIF)) and 2 untreated cases were included. BM VAF dynamics are shown with a dotted line and cfDNA dynamics are shown with a solid line. [Display omitted] DisclosuresBesses: Gilead: Research Funding. Salar: Janssen: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Gilead: Research Funding; Celgene: Consultancy, Speakers Bureau. Bellosillo: Thermofisher Scientific: Consultancy, Speakers Bureau; Roche: Research Funding, Speakers Bureau; Qiagen: Consultancy, Speakers Bureau.

Customer-Server Population Dynamics in Heavy Traffic

We study a many-server queueing model with server vacations, where the population size dynamics of servers and customers are coupled: a server may leave for vacation only when no customers await, and the capacity available to customers is directly affected by the number of servers on vacation. We focus on scaling regimes in which server dynamics and queue dynamics fluctuate at matching time scales so that their limiting dynamics are coupled. Specifically, we argue that interesting coupled dynamics occur in (a) the Halfin–Whitt regime, (b) the nondegenerate slowdown regime, and (c) the intermediate near Halfin–Whitt regime, whereas the dynamics asymptotically decouple in the other heavy-traffic regimes. We characterize the limiting dynamics, which are different for each scaling regime. We consider relevant respective performance measures for regimes (a) and (b)—namely, the probability of wait and the slowdown. Although closed-form formulas for these performance measures have been derived for models that do not accommodate server vacations, it is difficult to obtain closed-form formulas for these performance measures in the setting with server vacations. Instead, we propose formulas that approximate these performance measures and depend on the steady-state mean number of available servers and previously derived formulas for models without server vacations. We test the accuracy of these formulas numerically.

Cooperative Cloud-Edge Feature Extraction Architecture for Mobile Image Retrieval

Mobile image retrieval greatly facilitates our lives and works by providing various retrieval services. The existing mobile image retrieval scheme is based on mobile cloud-edge computing architecture. That is, user equipment captures images and uploads the captured image data to the edge server. After preprocessing these captured image data and extracting features from these image data, the edge server uploads the extracted features to the cloud server. However, the feature extraction on the cloud server is noncooperative with the feature extraction on the edge server which cannot extract features effectively and has a lower image retrieval accuracy. For this, we propose a collaborative cloud-edge feature extraction architecture for mobile image retrieval. The cloud server generates the projection matrix from the image data set with a feature extraction algorithm, and the edge server extracts the feature from the uploaded image with the projection matrix. That is, the cloud server guides the edge server to perform feature extraction. This architecture can effectively extract the image data on the edge server, reduce network load, and save bandwidth. The experimental results indicate that this scheme can upload few features to get high retrieval accuracy and reduce the feature matching time by about 69.5% with similar retrieval accuracy.

Suggestions to improve shortcoming in reporting and data collection procedure for studies of injuries in Kabaddi

Objectives: Kabaddi is a commonly played sport in Asia and now it is getting recognition worldwide. With the emergence of this sport, concern related to injuries associated with this sport is also increasing. For uniform reporting of injuries and illness in the epidemiological study (Kabaddi), it desired to have standard definitions on Kabaddi-related injuries. Materials and Methods: After the initial review of various studies on other sports; the definitions and terms which can be valid for Kabaddi were selected and modified according to this sport. These definitions were then reviewed by experts, who have an abundance of experiences in the treatment of injuries related to this sport. After multiple meetings among the expert panel final definitions, terms, and methodology for injury surveillance studies were laid down. Results: Only new and modified definitions were used in this paper, therefore, it is advised to use this paper in conjunction with STROBE-SIS. Injury rates were defined per 1000 raids or 1000 tackles. Various definitions like match time loss, general time loss, match injury incidence, training injury incidence, match injury prevalence, etc. were included in this paper. Conclusion: These standard definitions will help inconsistent and better data collection in injury surveillance studies. This will also help in a better understanding of injury patterns.

1019 Quantified Learning Curves for Robotic Gastrointestinal Surgery

Abstract Aim Robotic techniques are increasingly being adopted by gastrointestinal surgeons. It is important to understand the learning curves (LCs) for robotic surgery, to protect patients from harm caused by surgeon inexperience. The aim of this study was to summarise reports of the LC for three robotic gastrointestinal procedures: cholecystectomy, oesophagectomy and Roux-en-Y gastric bypass (RYGB). Method Three systematic reviews were conducted by the trainee led RoboSurg Collaborative. Systematic searches identified reports of primary clinical research involving robotic cholecystectomy, oesophagectomy and RYGB. Articles were screened in duplicate by title, abstract and then full text. References to the LC were extracted and coded. Quantifications of the learning curve were summarised using descriptive statistics. Results 259 articles were identified: 56 measured the LC, with 23 (9%) of these calculating the number of cases required to complete the LC. The mean reported number of cases at which the LC plateaued was: 16 for oesophagectomy (N = 6, SD = 3.7), 18 for cholecystectomy (N = 5, SD = 15.1), 34 for RYGB (N = 12, SD = 24.6). The reported LCs often incorporated equipment setup times, and so represents learning of the team as well as the surgeon. These values represent points on the LC that authors deemed their surgeons to have ‘completed’ learning. Definitions for when these points occurred varied greatly but largely fell in to two categories: ‘plateau of operative time’ or ‘matching operating time of laparoscopic control procedure’. Conclusions The heterogeneity in how LCs are defined, measured, and reported highlights the need for a more standardised approach when evaluating novel techniques such as robotics.

Hybrid Approach for Enhancing Performance of Genomic Data for Stream Matching

In gene expression analysis, the expression levels of thousands of genes are analyzed, such as separate stages of treatments or diseases. Identifying particular gene sequence pattern is a challenging task with respect to performance issues. The proposed solution addresses the performance issues in genomic stream matching by involving assembly and sequencing. Counting the k-mer based on k-input value and while performing DNA sequencing tasks, the researches need to concentrate on sequence matching. The proposed solution addresses performance issue metrics such as processing time for k-mer counting, number of operations for matching similarity, memory utilization while performing similarity search, and processing time for stream matching. By suggesting an improved algorithm, Revised Rabin Karp(RRK) for basic operation and also to achieve more efficiency, the proposed solution suggests a novel framework based on Hadoop MapReduce blended with Pig &amp; Apache Tez. The measure of memory utilization and processing time proposed model proves its efficiency when compared to existing approaches.

Analysis of dynamic characteristics and influencing factors of steam dump conditions of marine nuclear power plant

Objectives Based on the operation requirements of steam bypass exhaust system of marine nuclear power plant, the dynamic characteristics and influencing factors of bypass exhaust conditions are analyzed. Methods According to the functional characteristics of the steam bypass exhaust system, the mathematical and physical models of the matching operation of the steam generator, steam system, bypass system and main steam turbine are established. The dynamic operation characteristics and the coupling matching characteristics of the primary and secondary circuits under extreme working conditions such as quick closing of the main steam valve and load rejection of the steam turbine are analyzed to verify the accuracy and universality of the simulation model. Results The simulation results show that when operating under bypass exhaust condition, the appropriate bypass exhaust valve, main steam valve and their matching action time should be selected according to the power self-regulation capacity of the marine reactor, and the safety problems such as overpressure of the steam header and overspeed of the steam turbine unit should be comprehensively considered. At the same time, the steam demand of other equipments on the ship should be met. Conclusions The research results can provide reference for the safety control of side exhaust conditions and the optimal design of side exhaust system of nuclear power plant.

Offline signature recognition system using oriented FAST and rotated BRIEF

Despite recent developments in offline signature recognition systems, there is however limited focus on the recognition problem facet of using an inadequate sample size for training that could deliver reliable and easy to use authentication systems. Signature recognition systems are one of the most popular biometric authentication systems. They are regarded as non-invasive, socially accepted, and adequately precise. Research on offline signature recognition systems still has not shown competent results when a limited number of signatures are used. This paper describes our proposed practical offline signature recognition system using the oriented FAST and rotated BRIEF (ORB) feature extraction algorithm. We focus on the practicality of the proposed system, which requires only the minimum number of signatures per user to achieve a high level of fidelity. We manifest the practicality of our approach with a signature database of 300 signatures from 100 different individuals, implying that only two signatures are needed per person to train the proposed system. Our proposed solution achieves a 91% recognition rate with a median matching time of only 7 ms.

A maximum diversity-based path sparsification for geometric graph matching

This paper presents an effective dissimilarity measure for geometric graphs representing shapes. The proposed dissimilarity measure is a distance that combines a sparsification of the geometric graph based on the maximum diversity problem and a new node embedding that captures the topological neighborhood of nodes. The sparsification step aims to reduce the size of the graph and to correct the misdistribution of nodes on the geometric graph induced by the noise of image handling. Experimental evaluation shows that the sparsification algorithm retains the form of the shapes while decreasing the number of processed nodes which reduces the overall matching time. Furthermore, the proposed node embedding and similarity measure give better performance in comparison with existing graph matching approaches.

Carpooling Platforms as Smart City Projects: A Bibliometric Analysis and Systematic Literature Review

Carpooling schemes for mutual cost benefits between the driver and the passengers has a long history. However, the convenience of driving alone, the increasing level of car ownership, and the difficulties in finding travelers with matching timing and routes keep car occupancy low. Technology is a key enabler of online platforms which facilitate the ride matching process and lead to an increase in carpooling services. Smart carpooling services may be an alternative and enrichment for mobility, which can help smart cities (SCs) reduce traffic congestion and gas emissions but require the appropriate architecture to support connection with the city infrastructure such as high-occupancy vehicle lanes, parking space, tolls, and the public transportation services. To better understand the evolution of carpooling platforms in SCs, bibliometric analysis of three separate specialized literature collections, combined with a systematic literature review, is performed. It is identified that smart carpooling platforms could generate additional value for participants and SCs. To deliver this value to an SC, a multi-sided platform business model is proposed, suitable for a carpooling service provider with multiple customer segments and partners. Finally, after examining the SC structure, a carpooling platform architecture is presented, which interconnects with the applicable smart city layers.

Mobile Augmented Reality for Low-End Devices Based on Planar Surface Recognition and Optimized Vertex Data Rendering

Mobile Augmented Reality (MAR) is designed to keep pace with high-end mobile computing and their powerful sensors. This evolution excludes users with low-end devices and network constraints. This article presents ModAR, a hybrid Android prototype that expands the MAR experience to the aforementioned target group. It combines feature-based image matching and pose estimation with fast rendering of 3D textured models. Planar objects of the real environment are used as pattern images for overlaying users’ meshes or the app’s default ones. Since ModAR is based on the OpenCV C++ library at Android NDK and OpenGL ES 2.0 graphics API, there are no dependencies on additional software, operating system version or model-specific hardware. The developed 3D graphics engine implements optimized vertex-data rendering with a combination of data grouping, synchronization, sub-texture compression and instancing for limited CPU/GPU resources and a single-threaded approach. It achieves up to 3× speed-up compared to standard index rendering, and AR overlay of a 50 K vertices 3D model in less than 30 s. Several deployment scenarios on pose estimation demonstrate that the oriented FAST detector with an upper threshold of features per frame combined with the ORB descriptor yield best results in terms of robustness and efficiency, achieving a 90% reduction of image matching time compared to the time required by the AGAST detector and the BRISK descriptor, corresponding to pattern recognition accuracy of above 90% for a wide range of scale changes, regardless of any in-plane rotations and partial occlusions of the pattern.

Surgical Precision and Efficiency of a Novel Electromagnetic System Compared to a Robot-Assisted System in Percutaneous Pedicle Screw Placement of Endo-LIF.

Retrospective database study. To compare the accuracy and safety of 2 types of a computer-assisted navigation system for percutaneous pedicle screw placement during endoscopic lumbar interbody fusion. From May 2019 to January 2020, data of 56 patients who underwent Endo-LIF with a robot-assisted system and with an electromagnetic navigation system were compared. The pedicles in all patients were subjected to postoperative CT scan to assess screw correction by measuring the perpendicular distance between the pedicle cortical wall and the screw surface. The registration and matching time, guide-wire insertion time, the entire surgery time, and X-ray exposure time were recorded. In the robot-assisted group, 25 cases with 100 percutaneous pedicle screws were included, and the excellent and good rate was 95%. In the electromagnetic navigation group, 31 cases with 124 screws were included, and the excellent rate was 97.6%. There was no statistical difference between the two groups (P > 0.05). The registration time and the total time for the surgery also showed no statistical differences (P > 0.05). The main difference between the two groups was the guide-wire insertion time and the X-ray exposure time (P < 0.05). Both electromagnetic navigation and robot-assisted are safe and efficient for percutaneous pedicle screw placement. Electromagnetic navigation system has obvious advantages over robot-assisted in terms of faster guide-wire placement and less X-ray exposure. Robot-assisted for percutaneous pedicle screw placement offers a preoperative planning system and a stable registration system, with obvious drawbacks of a strict training curve.

Comparison of the activity profile during Grand Slam women’s doubles tennis

ABSTRACT There is little information on the female doubles tennis. The aim of this study was to describe the activity profile of women’s doubles tennis, and to analyse the differences between playing surfaces. Twenty-one matches of three Grand Slams (GS) tournaments and played on 3 different surfaces, were analysed. Activity profile included rally duration (RD), resting time between points (RTP), resting time between games (RTG), resting time between sets (RTS), resting time (RT), effective playing time (EPT), total match time (TMT), work-to-rest ratio (W: R), shots per rally (SPR), shots per game (SPG), shots per set (SPS), shots per match (SPM), shot frequency (shots/second) (SPSc), and type of shots. Results showed that RTG and RT was longer at the Australian Open than at Roland Garros and Wimbledon, and the number of forehand (F) shots at Roland Garros was higher than at Wimbledon. The most common tennis shots are the F, the backhand (B), the first service and the volley (V), and more than 50% of the total shots in a match come from the baseline and mid court game. These results show that in women’s doubles the stimuli are short and intense and that net game is very important.

Lymphoma complicating rheumatoid arthritis: results from a French case–control study

ObjectivesTo study the characteristics of B-cell non-Hodgkin’s lymphoma (NHL) or Hodgkin lymphoma complicating rheumatoid arthritis (RA) and to identify RA-related factors associated with their occurrence.MethodsA multicentre case–control study was performed...

Research on Stereo Vision Technology Based on Improved Region Growing Method

Image segmentation is the cornerstone of image analysis and image processing, its main difficulty is the ill-posedness of image segmentation. The region growing method is the most commonly used method in image segmentation. Its advantages are fast calculation speed, lower algorithm difficulty, and easy understanding. This article uses the area growing algorithm and TOF combined with binocular fusion technology. Discussed how to select the seed points in the region growing method. The algorithm proposed in this paper has high accuracy and high matching quality in the boundary area of the object and the area with large difference in depth. It has both matching time and reliability. It has good results and overcomes the limitations of the active and passive distance methods in the vision system.