Single AP Research Articles

DIP-MS: ultra-deep interaction proteomics for the deconvolution of protein complexes

Most proteins are organized in macromolecular assemblies, which represent key functional units regulating and catalyzing most cellular processes. Affinity purification of the protein of interest combined with liquid chromatography coupled to tandem mass spectrometry (AP–MS) represents the method of choice to identify interacting proteins. The composition of complex isoforms concurrently present in the AP sample can, however, not be resolved from a single AP–MS experiment but requires computational inference from multiple time- and resource-intensive reciprocal AP–MS experiments. Here we introduce deep interactome profiling by mass spectrometry (DIP-MS), which combines AP with blue-native-PAGE separation, data-independent acquisition with mass spectrometry and deep-learning-based signal processing to resolve complex isoforms sharing the same bait protein in a single experiment. We applied DIP-MS to probe the organization of the human prefoldin family of complexes, resolving distinct prefoldin holo- and subcomplex variants, complex–complex interactions and complex isoforms with new subunits that were experimentally validated. Our results demonstrate that DIP-MS can reveal proteome modularity at unprecedented depth and resolution.

Reinforcement learning-based resource allocation for dynamic aggregated WiFi/VLC HetNet

High transmission rates and low power consumption make visible light communication (VLC) a highly promising supplementary technology for the next generation of mobile communication. Taking into account the limited coverage area, VLC can be combined with WiFi as a heterogeneous network (HetNet), thanks to their non-overlapping spectrum. In order to fully utilize the advantages of the WiFi and VLC technologies, a new aggregated WiFi/VLC HetNet consisting of a single WiFi AP and multiple VLC APs, is designed, where the user equipment (UE), for the first time, can access multiple VLC APs and one WiFi AP simultaneously, and be allowed to acquire multiple resource blocks (RB) in each AP at the same time. To optimize the performance of the above designed HetNet, a multi-objective optimization problem (MOOP) is formulated, which aims to maximize system throughput while reducing the handover rate. Since the above MOOP is non-convex and nonlinear, the traditional resource allocation (RA) algorithm has a complex calculation process and poor timeliness performance to deal with this problem. To solve the above MOOP, a reinforcement learning (RL)-based RA algorithm is proposed, and considering the RB handover overhead in the aggregated WiFi/VLC HetNet, a reward function related to the system throughput and the UE handover rate is carefully designed. System throughput, system handover rate, user satisfaction, as well as user fairness performance are analyzed under three typical indoor illumination layouts. Finally, compared with the greedy algorithm and the hypergraph-based carrier aggregation algorithm, numerical results show that the proposed RL-based RA algorithm could improve the system throughput over the former two algorithms by 30.26% and 19.71%, while reducing the system handover rate by 0.15% and 0.02%, respectively.

HLoc: Exploiting Height Difference for WiFi Indoor Localization with Single Commercial AP

HLoc: Exploiting Height Difference for WiFi Indoor Localization with Single Commercial AP

Artificial Intelligence Autonomously Measures Cup Orientation, Corrects for Pelvis Orientation, and Identifies Retroversion From Antero-Posterior Pelvis Radiographs

BackgroundMeasuring cup orientation is time consuming and inaccurate, but orientation influences the risk of impingement and dislocation following total hip arthroplasty (THA). This study designed an artificial intelligence (AI) program to autonomously determine cup orientation, correct for pelvis orientation, and identify cup retroversion from an antero-posterior pelvic radiographs. MethodsThere were 2,945 patients between 2012 and 2019 identified to have 504 computed tomographic (CT) scans of their THA. A 3-dimensional (3D) reconstruction was performed on all CTs, where cup orientation was measured relative to the anterior pelvic plane. Patients were randomly allocated to training (4,000 x-rays), validation (511 x-rays), and testing (690 x-rays) groups. Data augmentation was applied to the training set (n = 4,000,000) to increase model robustness. Statistical analyses were performed only on the test group in their accuracy with CT measurements. ResultsAI predictions averaged 0.22 ± 0.03 seconds to run on a given radiograph. Pearson correlation coefficient was 0.976 and 0.984 for AI measurements with CT, while hand measurements were 0.650 and 0.687 for anteversion and inclination, respectively. The AI measurements more closely represented CT scans when compared to hand measurements (P < .001). Measurements averaged 0.04 ± 2.21°, 0.14 ± 1.66°, −0.31 ± 8.35°, and 6.48° ± 7.43° from CT measurements for AI anteversion, AI inclination, hand anteversion, and hand inclination, respectively. AI predictions identified 17 radiographs as retroverted with 100.0% accuracy (total retroverted, n = 45). ConclusionThe AI algorithms may correct for pelvis orientation when measuring cup orientation on radiographs, outperform hand measurements, and may be implemented in a timely fashion. This is the first method to identify a retroverted cup from a single AP radiograph.

A Non-Line-of-Sight Wireless Indoor Localization System Using Custom-Designed Radio Relay and Uniform Circular Array

Indoor localization using WiFi signals, though getting studied for many years, is not adopted extensively in real indoor environments yet. One possible impediment is that many prior systems perform worse in non-line-of-sight (NLoS) indoor scenarios than in line-of-sight (LoS) scenarios or even fail to work. Nevertheless, realizing localization in both LoS and NLoS scenarios is indispensable for a viable system working in indoor environments. Since existing state-of-the-art solutions mainly aim to localize a target in LoS indoor scenarios, we present a system that uses multipath channel parameters to achieve localization with a single AP in indoor NLoS scenarios. The proposed introduces deployable and simple custom-designed radio relays to assist localization, which can receive signals from the target and forward them to the AP in NLoS scenarios. Field trials conducted in a real NLoS scenario show that our system achieves a median 3-D localization accuracy of 86 cm with a uniform circular array (UCA) in most NLoS conditions, i.e., the direct path from a target to AP is not completely blocked. More importantly, even if in a challenging NLoS condition, i.e., the direct path does not exist, our system can still achieve a median 2-D localization accuracy of 85 cm.

Simulation and performance evaluation of IEEE802.11 WLAN under different operating conditions

A wireless local area network (WLAN) based on IEEE802.11 protocol is the essential part for connection to the internet .and it is widely used in our life today and tomorrow. The growth in the number of nodes per small area likes home, office, and so on. This increase in density led to the degradation in performance in terms of throughput and delay experienced by the end-users. So many amendments proposed in order to improve the performance. Then the performance evaluation of WLAN is an important research topic. In this paper, the performance of WLAN working at 2.4GHz and 5 GHz assessed in a home-like area under the widely used applications the assessment is in terms of throughput and delay. The evaluation conducted by using the optimum networks (OPNET) 14.5 modeler simulator. In this work, we concluded that: using a single AP showed degradation in performance due to congestion. Because all nodes use the same transmission channel which showed clearly in the case of the data rate of 6 Mbps in both (a and g) standards. The effectiveness is about (1.1%, 1.3%) respectively. While using two APs improves the performance for the same case to about (28% and 65%) since it mitigates the congestion because each AP uses a different communication channel.

Function of KCNQ2 channels at nodes of Ranvier of lumbar spinal ventral nerves of rats

Previous immunohistochemical studies have shown the expression of KCNQ2 channels at nodes of Ranvier (NRs) of myelinated nerves. However, functions of these channels at NRs remain elusive. In the present study, we addressed this issue by directly applying whole-cell patch-clamp recordings at NRs of rat lumbar spinal ventral nerves in ex vivo preparations. We show that depolarizing voltages evoke large non-inactivating outward currents at NRs, which are partially inhibited by KCNQ channel blocker linopirdine and potentiated by KCNQ channel activator retigabine. Furthermore, linopirdine significantly alters intrinsic electrophysiological properties of NRs to depolarize resting membrane potential, increase input resistance, prolong AP width, reduce AP threshold, and decrease AP amplitude. On the other hand, retigabine significantly decreases input resistance and increases AP rheobase at NRs. Moreover, linopirdine increases excitability at NRs by converting single AP firing into multiple AP firing at many NRs. Saltatory conduction velocity is significantly reduced by retigabine, and AP success rate at high stimulation frequency is significantly increased by linopirdine. Collectively, KCNQ2 channels play a significant role in regulating intrinsic electrophysiological properties and saltatory conduction at NRs of motor nerve fibers of rats. These findings may provide insights into how the loss-of-function mutation in KCNQ2 channels can lead to neuromuscular disorders in human patients.

Paper 66: Radiostereometric Analysis of Biceps Tenodesis: A Prospective Comparison of All-Suture Anchor vs. Interference Screw, Arthroscopic and Mini-Open Techniques

Objectives:Recent studies suggest that similar results can be achieved via arthroscopic and open biceps tenodesis techniques. The purpose of this investigation was to quantify and compare the behavior of the biceps tenodesis construct in arthroscopic suprapectoral (ASPBT) and open subpectoral (OSPBT) techniques performed with either interference screw or suture anchor fixation, with radiostereometric analysis (RSA).Methods:A prospective cohort study was performed comparing migration of the biceps tendon after suprapectoral and subpectoral biceps tenodesis (BT) with Polyetheretherketone (PEEK) interference screw vs. all-suture suture anchor (ASSA) fixation. Patients with symptomatic biceps tendinopathy, anterior intertubercular groove tenderness, and positive biceps tension tests were included in the investigation. A tantalum bead, functioning as a radiostereometric marker, was sutured to the biceps tendon before final fixation of tendon tissue with either an interference screw or suture anchor. Following final fixation, AP radiographs were obtained intraoperatively. Follow up single view AP radiographs were obtained at one week and 3-months post-operatively. The distance from the center of the tantalum bead to the most proximal aspect of the humeral head was measured.Results:Of 128 patients enrolled, 120 (93.8%) were available for follow-up. The average age was 52.05±10.5 years, average BMI 30.8±5.4, and 29% of the patients were females. Groups were similar concerning patient demographics and concomitant procedures. At final follow up, there was no difference in distal migration between the OSPBT and ASPBT performed with an interference screw (4.31 vs. 4.02 mm, respectively, P=0.418). BT performed with a single ASSA demonstrated significantly more migration than BT performed with double ASSA (27.24 vs. 9.73 mm, respectively, P=0.005) and significantly more migration than the interference screw (27.24 26 vs. 4.31 mm, respectively, P<0.001). BT performed with the double ASSA technique demonstrated significantly more migration than the interference screw (9.73 vs. 4.02 mm, respectively, P=0.041). Three patients (11.1%) in the open single ASSA group, one patient in the arthroscopic double ASSA group (4.0%) suffered Popeye deformities. None of the patients in the interference screw cohorts experienced Popeye deformities.Conclusions:OSPBT and ASPBT demonstrate similar construct stability with use of interference screws as assessed by RSA. BT performed with single ASSA fixation resulted in more distal migration compared to double ASSA and interference screw fixation. Interference screw fixation provided more construct stability compared to a single and double ASSA, whether performed arthroscopically or with an open approach. These findings are the first in vivo results to characterize and quantify the biceps tenodesis construct in the post-operative period.Table 1.Patient Demographics and Other Characteristics.Table 2.Intraoperative Findings.Table 3.Tantalum bead migration at 1 week, 3 months and between 1 week and 3 months for arthroscopic and open techniques.Figure 1.Comparison of postoperative construct migration for the four studied techniques of biceps tenodesis measured by radiostereometric analysis.

Understanding the Key Features of Wi-Fi 6 and Exploring the Effect of Modulation Scheme on Throughput Rate

Today, the number of smart devices and applications are increasing day by day, whereas the older versions of Wi-Fi stander, i.e., n/a/g cannot meet the greed and need of these devices. Thus, the development of applications and devices has called to design of a new Wi-Fi version. Hence, a new Wi-Fi 6 vision has been promoted based on 802.11 IEEE stander. The scope of this paper has focused on the study and overview of Wi-Fi 6 features. As well as, exploring the simulation tools that can be used to implement 802.11ax. A simulation has been done by using NS-3 to measure the effect of modulation and coding schemes on the throughput rate. Where a scenario of the network model was taken on a single AP with a node and the MCS value range is (0 to 7), the channel width (20, 40, 80 or 160 MHz) and the guard interval (800ns, 1600ns or 3200ns). The time of simulation was set to 10 seconds. Hence, the output results explained that the change of modulation properties can increase/reduce the throughput rate.

Wi-Fi Direction Finding With Frequency-Scanned Antenna and Channel-Hopping Scheme

A novel and simple technique for Direction of Arrival (DoA) estimation in 802.11 Wi-Fi networks is proposed. It is based on the use of a dual-port frequency-beam scanning antenna, which is connected to single MIMO access point. By simply performing a channel hopping scheme and acquiring Received Signal Strength Information (RSSI) from each channel, the DoA can be estimated in a wide Field of View of 180° with a mean angular error of 5°. Due to its simplicity, a single commodity Wi-Fi AP can be used without the need of Channel State Information (CSI), or complex electronically reconfigurable or mechanically revolving antennas.

A260 ACUTE PANCREATITIS IN JORDANIAN CHILDREN

BackgroundAcute pancreatitis is a uncommon disease in children. The difference between pediatric and adult pancreatitis limit the ability of extrapolating the adults data and magnify the need for further pediatric research.AimsWe aimed to describe the demographics, clinical presentation and findings of acute pancreatitis in Jordanian children. In addition, we discuss the diagnostic criteria of AP and compare the role of various labratory and radiological investigations in the diagnostic process in our cohort.MethodsThis is a retrospective study involving children below 18 years of age, diagnosed with acute pancreatitis at King Abdullah University Hospital, a tertiary healthcare center in Irbid, Jordan.Patient electronic records from 2011 to 2020 were manually reviewed and data collected into an excel sheet. The data included their demographics (Age, sex, age at first recurrence in case of recurrent pancreatitis) and clinical data (presentation, physical findings, laboratory and radiological investigations, interventions and outcomes). Those with insufficient data were excluded.ResultsA total of 22 patients with 59 episodes of AP were identified. Of those patients, 11 (50%) were males, and 11 (50%) had only a single AP episode. The mean age during the first attack of AP was 10 years (SD = 3.6 y, N = 21) and the youngest was 3.45 years.Of the 22 patients who had the first AP episode, 11 (50%) had at least one more episode of AP later on. In those who did have recurrence; The median duration between the first and second episodes was 2.7 months, IQR = 11 mo. The median length of hospital stay was 3 days, IQR = 4 days.Abdominal pain was the most common presenting symptom of AP (96%). Nausea and vomiting were less common (67% and 50%, respectively).The cause of pancreatitis was identified in 18 (82%) children, while 4 (18%) were labelled as idiopathic. The most common known cause in our cohort was congenital biliary-pancreatic abnormalities; namely choledochal cyst and pancreatic divisum (6, 27%) followed by genetic cause (4, 18%) and biliary pancreatitis (4,18%).Abdominal ultrasound (US) was the most used diagnostic imaging (33 exams). The most common finding was bulky and enlarged pancreas in 9 exams. MRCP evaluation was available for 10 episodes; 3 exams showed a normal pancreas, while 2 confirmed the suspicion of pancreatic divisum, 1 suggested cholangitis. 1 visualized a small choledochal cyst that was undetected with neither US nor CT.Development of peripancreatic fluid collection (pseudocyst) was seen in 4 patients, two of which underwent intervention, one was treated with endoscopic gastro-cystic drainage and the other was treated with surgical drainage. Of the 22 children and 59 AP episodes, only 1 died.ConclusionsAcute pancreatitis is uncommon in Jordanian children. Although the small number in our cohort, we reported different etiological spectrum compared to reported literture.Funding AgenciesNone

Performance Analysis of Mobile Edge Computing in Resource-Limited CSMA/CA Networks

Mobile Edge Computing (MEC) has proved its great potential for supporting the delay-stringent services in wireless networks. We notice that offloading performance of the MEC system is not only determined by the PHY-layer transmission rate, but also closely related to the performance of channel access and computation at the server. To this end, in this correspondence, we investigate a multiuser MEC system, where each user offloads packet to a single AP equipped with an MEC server by preempting the channel according to carrier sense multiple access with collision avoidance (CSMA/CA) protocol. We derive the effective offloading rate and delay by considering transmission outage caused by the poor channel condition, the MAC-layer channel competition, and the packet overflow due to the limited service capability of the server, where the service process is modelled as an M/M/1/B queue. The theoretical analysis is verified by extensive simulations, which has shown that the competition intensity indicated by the number of users and the packet length, as well as the processing capability of the MECserver including the buffer size and the computation speed, has profound impact on the offloading performance.

PMMC WITH TWO SEPARATE SKIN ISLANDS -AN UNIQUE TECHNIQUE AND ITS USE IN COMPLEX HEAD AND NECK DEFECTS

More than two thirds of oral cancer patients present in advanced stage in India, from subsites like Buccal mucosa and tongue often present with N3b nodes with skin involvement. This type of advanced disease usually requires composite resection and extended radical neck dissection. If both the defects are adjacent to each other can be addressed by bipaddle PMMC. If the signicant normal tissue lies between the primary and neck defects [level 2b,3,5] it should be Reconstruction with a single free ap or combination of free and locoregional aps. Free ap reconstruction requires expertise and other ancillary instruments which is difcult to organize in COVID situation. We overcame this problem by designing the PMMC in a unique manner with two island skin paddles based on the pectoral branch of thoraco-acromial vessels to cover both the defects.

Interstrand Cross-Link Formation Involving Reaction of a Mispaired Cytosine Residue with an Abasic Site in Duplex DNA.

The formation of interstrand cross-links in duplex DNA is important in biology, medicine, and biotechnology. Interstrand cross-links arising from the reaction of the aldehyde residue of an abasic (apurinic or AP) site with the exocyclic amino groups of guanine or adenine residues on the opposing strand of duplex DNA have previously been characterized. The canonical nucleobase cytosine has an exocyclic amino group but its ability to form interstrand cross-links by reaction with an AP site has not been characterized before now. Here it is shown that substantial yields of interstrand cross-links are generated in sequences having a mispaired cytosine residue located one nucleotide to the 3'-side of the AP site on the opposing strand (e.g., 5'XA/5'CA, where X = AP). Formation of the dC-AP cross-link is pH-dependent, with significantly higher yields at pH 5 than pH 7. Once formed, the dC-AP cross-link is quite stable, showing less than 5% dissociation over the course of 96 h at pH 7 and 37 °C. No significant yields of cross-link are observed when the cytosine residue is paired with its Watson-Crick partner guanine. It was also shown that a single AP site can engage with multiple nucleobase cross-linking partners in some sequences. Specifically, the dG-AP and dC-AP cross-links coexist in dynamic equilibrium in the sequence 5'CXA/5'CAG (X = AP). In this sequence, the dC-AP cross-link dominates. However, in the presence of NaBH3CN, irreversible reduction of small amounts of the dG-AP cross-link present in the mixture shifts the equilibria away from the dC-AP cross-link toward good yields of the dG-APred cross-link.

THE RISK OF CEREBRAL MICROBLEEDS IN ISCHEMIC STROKE PATIENTS USING ANTIPLATELET THERAPIES

Background: Interest in cerebral microbleeds (CMBs) has increased based on advances in magnetic resonance imaging (MRI) technology. Both MRI T2-weighted gradient-echo (GRE) and susceptibility-weighted imaging may be sensitive techniques for the detection of past and more recent brain hemorrhage. The prevalence of CMBs in healthy population ranges 3.7–7.7%, whereas in patients with intracerebral hemorrhage is thought to be around 60%.Objective: To evaluate the prevalence and possible risk of microbleeds among patients with ischemic stroke using antiplatelets (Aps).Patients and Methods: The observational hospital-based cross-sectional analytical study involved 150 consecutive patients with ischemic stroke (recent or old ischemic strokes or both), from inpatients of neurology departments of Ain Shams University Hospital and Agouza Police Hospital for a period of 15 months from April 2018 to June 2019.Results: Cerebral microbleeds were present in 13 patients representing 26% of the no AP group, 16 patients representing 32% of the single AP group and 19 patients representing 38% of the double AP group, there was no statistically significant difference between the three groups of patients. Cerebral microbleeds were present in 60% of patients on double APs and 37.5% of patient on single AP for more than two years, compared to 23.3%and 26.9%for the two groups respectively on APs for less than two years, In the current study we found that the significant risk factor for the presence of CMBs was the duration of APs use. There was no statistically significant difference in the laboratory data (including full lipid profile, HbA1c and platelet count) between the three groups.Conclusion: CMBs are significantly associated with long term use of antiplatelets, so careful clinical and radiological follow up of ischemic stroke patients with CMBs using antiplatelets for risk of future intracranial hemorrhage.

Application of a WiFi/Geomagnetic Combined Positioning Method in a Single Access Point Environment

Because of the particularity of urban underground pipe corridor environment, the distribution of wireless access points is sparse. It causes great interference to a single WiFi positioning method or geomagnetic method. In order to meet the positioning needs of daily inspection staff, this paper proposes a WiFi/geomagnetic combined positioning method. In this combination method, firstly, the collected WiFi strength data was filtered by outlier detection method. Then, the filtered data set was used to construct the offline fingerprint database. In the following positioning operation, the classical k‐nearest neighbor algorithm was firstly used for preliminary positioning. Then, a standard circle was constructed based on the points obtained by the algorithm and the actual coordinate points. The diameter of the standard circle was the error, and the geomagnetic data were used for more accurate positioning in this circle. The method reduced the WiFi mismatch rate caused by multipath effects and improved positioning accuracy. Finally, a positioning accuracy experiment was performed in a single AP distribution environment that simulates a pipe corridor environment. The results proves that the WiFi/geomagnetic combined positioning method proposed in this paper is superior to the traditional WiFi and geomagnetic positioning methods in terms of positioning accuracy.

Efficient Indoor Localization via Switched-Beam Antennas

Location-based services have become extremely popular. As a result, indoor localization has received a lot of attention from both industry and academia. Despite the plethora of existing approaches, no method can achieve high accuracy without major, expensive changes to existing systems. For example, to achieve good accuracy, fingerprinting methods require many APs within range of a client, time-of-arrival methods require tight synchronization, client hardware changes and line-of-sight, and direction-of-arrival methods require expensive antenna front ends and line-of-sight. In this paper, we take advantage of inexpensive, off-the-shelf switched-beam antennas (SBAs) to increase the diversity of measurements used for fingerprint-based localization. We show using experiments that a single AP equipped with $n$ n SBAs may infer equally rich localization information as $n$ n APs equipped with $n$ n omnidirectional antennas each, as long as the SBAs are properly configured. We then establish via extensive experiments that a single packet reception from a commodity client at a single AP equipped with a handful of SBAs (e.g., eight SBAs costing a couple of dollars more than omni antennas) achieves localization accuracy in the order of half a meter with or without line-of-sight, in any indoor environment, with zero airtime overhead and zero client support.

The Effect Of Age On The Lumbar Spine Of Cricket Fast Bowlers

Senior cricket fast bowlers (FB) have high lumbar spine bone mineral, particularly on the contralateral side to their bowling arm. It is thought that bone possesses its greatest ability to adapt to loading during adolescence but is unknown at what age asymmetry develops in FB and how adaptation develops with age. PURPOSE: To determine how lumbar bone mineral and geometrical properties differ according to age in FB. METHODS: With NHS and institutional ethics approval, 107 elite adolescent and senior male FB aged 14 to 35 years received a single AP lumbar spine DXA scan (GE Lunar iDXA, GE Healthcare, USA). Bone mineral density (BMD) and bone mineral content (BMC) were derived for each vertebra, along with average vertebral height and width, area and Z-score (Lunar enCore v17, GE Healthcare, USA). Custom regions of interest derived the bone mineral in the lateral third of the non-dominant (ND) and dominant (D) sides of the vertebral body (respective to bowling arm). FB were split into 14-15 (n=27), 16-17 (n=28), 18-19 (n=22), 20-24 (n=16), and 25+ (n=14) age groups. ANOVAs were used to compare the age group means for each variable, with FFM as covariate. RESULTS: Lumbar spine BMD, BMC, Z-score, area, width and height significantly differed between age groups at all vertebral levels (P<0.01), but differences in area and height were no longer significant with FFM included as a covariate (P≥0.38). Mean BMD (± SD) L1-L4 Z-scores increased progressively with age from +0.83 ± 1.24 at age 14-15 to +2.69 ± 1.17 at age 25+. BMD and BMC on the ND and D sides significantly differed with age (P≤0.04) and side (P<0.01), and by age on each side (P≤0.04) as highlighted at L3 in figure 1. CONCLUSIONS: Adaptation to fast bowling, in terms of whole vertebra and site-specific bone mineral, substantially increases with age particularly on the ND side.

A single psychotomimetic dose of ketamine decreases thalamocortical spindles and delta oscillations in the sedated rat

BackgroundIn patients with psychotic disorders, sleep spindles are reduced, supporting the hypothesis that the thalamus and glutamate receptors play a crucial etio-pathophysiological role, whose underlying mechanisms remain unknown. We hypothesized that a reduced function of NMDA receptors is involved in the spindle deficit observed in schizophrenia. MethodsAn electrophysiological multisite cell-to-network exploration was used to investigate, in pentobarbital-sedated rats, the effects of a single psychotomimetic dose of the NMDA glutamate receptor antagonist ketamine in the sensorimotor and associative/cognitive thalamocortical (TC) systems. ResultsUnder the control condition, spontaneously-occurring spindles (intra-frequency: 10–16 waves/s) and delta-frequency (1–4 Hz) oscillations were recorded in the frontoparietal cortical EEG, in thalamic extracellular recordings, in dual juxtacellularly recorded GABAergic thalamic reticular nucleus (TRN) and glutamatergic TC neurons, and in intracellularly recorded TC neurons. The TRN cells rhythmically exhibited robust high-frequency bursts of action potentials (7 to 15 APs at 200–700 Hz). A single administration of low-dose ketamine fleetingly reduced TC spindles and delta oscillations, amplified ongoing gamma-(30–80 Hz) and higher-frequency oscillations, and switched the firing pattern of both TC and TRN neurons from a burst mode to a single AP mode. Furthermore, ketamine strengthened the gamma-frequency band TRN-TC connectivity. The antipsychotic clozapine consistently prevented the ketamine effects on spindles, delta- and gamma−/higher-frequency TC oscillations. ConclusionThe present findings support the hypothesis that NMDA receptor hypofunction is involved in the reduction in sleep spindles and delta oscillations. The ketamine-induced swift conversion of ongoing TC-TRN activities may have involved at least both the ascending reticular activating system and the corticothalamic pathway.

Radiographic assessment of the cup orientation after total hip arthroplasty: a literature review.

Optimal acetabular cup orientation is of substantial importance to good long-term function and low complication rates after total hip arthroplasty (THA). The radiographic anteversion (RA) and inclination (RI) angles of the cup are typically studied due to the practicability, simplicity, and ease of interpretation of their measurements. A great number of methods have been developed to date, most of which have been performed on pelvic or hip anteroposterior radiographs. However, there are primarily two influencing factors for these methods: X-ray offset and pelvic rotation. In addition, there are three types of pelvic rotations about the transverse, longitudinal, and anteroposterior axes of the body. Their effects on the RA and RI angles of the cup are interactively correlated with the position and true orientation of the cup. To date, various fitted or analytical models have been established to disclose the correlations between the X-ray offset and pelvic rotation and the RA and RI angles of the cup. Most of these models do not incorporate all the potential influencing parameters. Advanced methods for performing X-ray offset and pelvic rotation corrections are mainly performed on a single pelvic AP radiograph, two synchronized radiographs, or a two-dimensional/three-dimensional (2D-3D) registration system. Some measurement systems, originally developed for evaluating implant migration or wear, could also be used for correcting the X-ray offset and pelvic rotation simultaneously, but some drawbacks still exist with these systems. Above all, the 2D-3D registration technique might be an alternative and powerful tool for accurately measuring cup orientation. In addition to the current methods used for postoperative assessment, navigation systems and augmented reality are also used for the preoperative planning and intraoperative guidance of cup placement. With the continuing development of artificial intelligence and machine learning, these techniques could be incorporated into robot-assisted orthopaedic surgery in the future.