Terms Of Rotation Research Articles

The effect of different insert design congruencies on the kinematics of a mobile bearing TKA: A cadaveric study

IntroductionTotal knee arthroplasty has proved to be a safe, effective and reproducible surgical treatment for patients with serious/advanced degenerative joint disease of the knee, but the optimal results after these implants can be achieved only if the joint kinematics and kinetics are carefully respected and not significantly altered after the replacement. In order to enhance the capability of matching the healthy configuration, therefore, different prosthesis models in terms of constraints and designs are available for the surgeons to choose among. As an example of this variety, mobile bearing models allow the surgeon to choose among different insert designs in terms of geometry and relative biomechanical approaches, with the relative performances depending on which one is adopted.This article aims to analyse the effect of different levels of congruency of mobile bearing inserts through an experimental activity performed on an ultra-congruent insert design, also referred as deep-dished. MethodsThe experimental activity followed the same protocol used in a previous study focused on the effect of symmetricity/asymmetricity (in order to allow a comparison among the results obtained), i.e. it analysed passive squat on 5 cadaveric knee specimens; internal-external rotations of femur and tibial insert respect to the tibia tray were thus measured via a motion capture system in order to compare the insert-femur relative rotation among the different congruency configurations. ResultsThe overall knee kinematic (in terms of flexion-extension and internal-external rotation ranges of motion) with an ultra-congruent insert did not differ from the ones found for the other inserts; the insert-femur rotation values, instead, returned to be between the ones obtained with the other two inserts. ConclusionIn terms of adaptability to tibio-femoral rotation, therefore, this insert represents a valid option for the surgeon seeking for an intermediate solution among the opposed approaches of the other two.

On the mathematical fluid dynamics of atmospheric gravity (buoyancy) waves

Starting from the general, governing equations for a viscous, compressible fluid written in rotating, spherical coordinates, with an associated prescription for its thermodynamics, we construct a general amplitude perturbation of the background state of the atmosphere. The background state, with a purely zonal flow (wind) is suitably non-dimensionalised and the thin-shell parameter introduced; this is the sole basis upon which we construct the asymptotic solution of this problem. A corresponding, but different, non-dimensionalisation is performed on the system representing the perturbation. This approach shows how the Boussinesq approximation arises, but it also shows that rotation (Coriolis) terms cannot be ignored. Furthermore, any consistent solution requires that changes in pressure, density and temperature, due to the passage of the wave, are all the same (asymptotic) size. Comparison is made with existing theories, and we comment on the new aspects that have been uncovered in this investigation. Finally, we indicate where these ideas might be taken in the future.

Satisfaction and Functional Outcome of Surgical Treatment in Patients with Brachial Plexus Injury: A Decade of Retrospective Comparative Study.

Brachial plexus injury (BPI) is a severe peripheral nerve injury resulting in physical disability. Few studies have investigated the postoperative functional status. We aimed to evaluate the satisfaction with surgical treatment in patients with BPI referred to the Panzdah-e Khordad Hospital, Tehran, Iran from 2011 to 2021. In this descriptive-analytical retrospective comparative study, physical examination, along with BrAT, and DASH questionnaires were used to evaluate the patients' status. Then the collected data on the patients' functional status and movements were collected. To compare the mean of quantitative variables before and after the surgery, the dependent t-student was used. Generally, the patients stated that they still had considerable difficulty doing most of the items of the questionnaires. Nevertheless, there was a significant difference between the following variables before and after surgery; shoulder abduction goniometry (0-150) and force (M0:M5), shoulder external rotation goniometry (0-90) and force (M0:M5)), shoulder forward flexion goniometry (0-180) and force (M0:M5)), elbow flexion goniometry (0- 150), elbow extension force (M0:M5), and wrist and finger muscle force (M0:M5) (P<0.001). Posterior approach in BPI surgery was associated with good outcomes in terms of shoulder external rotation and abduction. However, patients still suffered from difficulties in daily activities.

Comparison between upper thoracic spine mobilization and the Ergon technique in the treatment of mechanical neck pain

Upper thoracic spine mobilization and the Ergon technique are used to treat mechanical neck pain in order to speed recovery, promote tissue healing and improve range of motion. There have been a few studies discussing the Ergon IASTM and upper thoracic spine mobilization in patients with neck pain, but none compared the aforementioned techniques in the treatment of mechanical neck pain. This clinical trial was conducted on a sample of thirty participants (16 females and 14 males) with mechanical neck pain who were randomly divided into two groups: Upper Thoracic Spine Mobilization (n=15) and Ergon Technique (n=15). Twelve sessions were delivered to all participants over a four-week period, three days per week. Before and after treatment, pain severity was measured by Numeric Pain Rating Scale (NPRS), cervical spine's active range of motion was measured by using a Cervical Range of Motion (CROM) device, and cervical spine's disability index was measured by Neck Disability Index (NDI). The statistical analysis was carried out using the Statistical Package for Social Sciences (SPSS) version 25. Both groups showed improvement in neck pain, reduced functional disability and increased cervical range of motion after treatment. The upper thoracic spine mobilization group had significantly better results in terms of cervical left lateral flexion and left rotation ranges of motion, while the Ergon Technique group had significantly better results in terms of improvement of neck pain and reduction in functional disability. In conclusion, the upper thoracic spine mobilization was effective at increasing the range of motion of the cervical region, while the Ergon technique was effective at relieving pain and dysfunction in the cervical spine in patients with mechanical neck pain. Upper thoracic spine mobilization and the Ergon technique are used to treat mechanical neck pain in order to speed recovery, promote tissue healing and improve range of motion. There have been a few studies discussing the Ergon IASTM and upper thoracic spine mobilization in patients with neck pain, but none compared the aforementioned techniques in the treatment of mechanical neck pain. This clinical trial was conducted on a sample of thirty participants (16 females and 14 males) with mechanical neck pain who were randomly divided into two groups: Upper Thoracic Spine Mobilization (n=15) and Ergon Technique (n=15). Twelve sessions were delivered to all participants over a four-week period, three days per week. Before and after treatment, pain severity was measured by Numeric Pain Rating Scale (NPRS), cervical spine's active range of motion was measured by using a Cervical Range of Motion (CROM) device, and cervical spine's disability index was measured by Neck Disability Index (NDI). The statistical analysis was carried out using the Statistical Package for Social Sciences (SPSS) version 25. Both groups showed improvement in neck pain, reduced functional disability and increased cervical range of motion after treatment. The upper thoracic spine mobilization group had significantly better results in terms of cervical left lateral flexion and left rotation ranges of motion, while the Ergon Technique group had significantly better results in terms of improvement of neck pain and reduction in functional disability. In conclusion, the upper thoracic spine mobilization was effective at increasing the range of motion of the cervical region, while the Ergon technique was effective at relieving pain and dysfunction in the cervical spine in patients with mechanical neck pain.

(Digital Presentation) Chiroptical Effect in Aligned Carbon Nanotube Films

The dissymmetric interaction between circularly polarized light and solid-state materials is central to developing next-generation chiral photonic devices for applications such as spectroscopy and imaging. The strong quantum confinement in 1D single-wall carbon nanotubes (SWCNTs) features extraordinary electrical and optical properties and enables high-performance optoelectronic devices for the generation, modulation, and detection of light. The recent success of separating chirality-enriched [1], especially enantiomer-enriched, SWCNT suspensions and their macroscopic alignment assembly [2] further pushes the frontier of improving the performance and bringing new chiral functionalities of SWCNT-based optoelectronic devices. However, the chiroptical spectroscopy characterization mainly focuses on solution samples or individual SWCNTs. There has been no report of such studies in macroscopic solid-state films of SWCNTs. In this work, we investigate the circular dichroism (CD) spectroscopy of the solution and large-area films of non-racemic, chirality-mixture SWCNTs synthesized using the arc-discharge method. We prepared multiple films with various degrees of alignment using the controlled vacuum filtration method [2]. By carefully designing a cuvette that is manufactured through a stereolithography-type 3D printer (Fig. 1a) and performing a 4-configuration measurement by flipping and rotating samples (Fig. 1b), the effects from linear dichroism and birefringence can be minimized [3]. As expected, both solution and random film samples displayed zero CD; see Fig. 1c. In stark contrast, the aligned films displayed strong CD signals (~ 480 mdeg at the peak position). More surprisingly, the signs of obtained CD signals from different aligned films can be completely opposite even though their degrees of alignment, in terms of reduced linear dichroism (LDr) at the wavelength of 1035 nm, and thicknesses are nearly the same; see Fig. 1c. We will discuss possible origins of these surprising chiroptical responses in terms of slight and gradual twisted rotations of alignment directors, which can happen during spontaneous alignment in the vacuum filtration process.[1] Ichinose, Y., Eda, J., Yomogida, Y. et al. Extraction of High-Purity Single-Chirality Single-Walled Carbon Nanotubes through Precise pH Control Using Carbon Dioxide Bubbling. The Journal of Physical Chemistry C 121, 13391-13395 (2017).[2] He, X., Gao, W., Xie, L. et al. Wafer-scale monodomain films of spontaneously aligned single-walled carbon nanotubes. Nature Nanotech 11, 633–638 (2016).[3] Albano, G., Pescitelli, G. et al. Chiroptical Properties in Thin Films of π-Conjugated Systems. Chemical Reviews 120 , 10145-10243 (2020). Figure 1

Stable striped state in a rotating two-dimensional spin–orbit coupled spin-1/2 Bose–Einstein condensate

We consider an effective two-dimensional Bose–Einstein condensate with some spin–orbit coupling (SOC) and a rotation term in an external harmonic potential. We find the striped state, and analyze the effects of SOC, the external potential, and the rotation frequency/direction on the profile and the stability of the striped state. Without the rotation term, the two spinor components exhibit striped pattern, and the numbers of stripes in the two components are always an odd–even or an even–odd. With the increase of the SOC strength, the number of stripes in both components increases, while the difference of the striped numbers is always one. After adding the rotation term, the profiles of the spinor components change qualitatively, and the change regulation of the striped numbers differs, while the difference of the striped numbers is still one. In addition, we find that the rotation direction only makes the striped state of the two spinor components exchange each other, though the clockwise and counterclockwise rotation directions are inequivalent with the presence of SOC. Such regulation is different from the previous study. And the rotation frequency gives rise to the transition from the striped state to a mixture of the striped state and vortex state. Furthermore, we prove the stability of these states by the evolution and linear stability analysis.

Allelopathic sorghum aqueous root extracts inhibit germination and seedling growth of crops and weeds

Allelopathic sorghum aqueous extracts can be used as sprays against weeds of arable lands. Water-soluble allelochemicals in the aqueous extracts may also negatively affect crops. Root aqueous extracts from the South African landrace sorghum IS9456 and the Botswanan commercial variety Mahube, with high (584.69 µg mg-1 root fresh weight) and low (17.38 µg mg-1 root fresh weight) sorgoleone contents respectively, were tested on germination, radicle length, plumule length and dry weight of goosegrass [Eleusine indica (L.) Gaertn], blackjack [Bidens pilosa (L.)], maize [Zea mays (L.)], soya bean [Glycine max (L.) Merr.] and wheat [Triticum aestivum (L.)]. Factors in five glasshouse experiments were the two sorghum varieties and four root extract solutions (0%, 5%, 10% and 20%) (w/v) arranged in a randomised complete block design with six replications. There was no significant effect (P&gt;0.05) of variety and root aqueous extract on germination, radicle length, plumule length and dry weight of maize and on germination of wheat and goosegrass. The sorghum accession IS9456 significantly (P&lt;0.05) reduced plumule length and dry weight of wheat and goosegrass and germination, plumule length and dry weight of soya bean and blackjack compared to Mahube. Increasing strength of root aqueous extract solution significantly (P&lt;0.001) reduced plumule length and dry weight of wheat and goosegrass as well as germination and dry weight of soya bean and blackjack. Extracts from IS9456 had greater inhibitory effects on crop and weed germination and growth compared to those from Mahube. Due to its low sorgoleone content and weak weed suppression from its root aqueous extracts, Mahube may have low potential for use in allelopathic weed control. The sorghum accession IS9456, which also produces very high sorgoleone content, may be used in integrated weed management exploiting allelopathy from both sorgoleone and water-soluble allelochemicals, although farmers will have to be careful in terms of crop rotations since the aqueous extracts also inhibit germination and growth of some crops. Field studies may be required to further confirm allelopathic effects of root aqueous extracts from IS9456. Key words: sorghum allelopathy, aqueous extracts, germination, growth, maize, soya bean, goose grass, blackjack

Simplified Evaluation of Plastic Rotation Demand for Existing EBFs Equipped with Short Links

The seismic events that occurred in the last decades have highlighted the importance of a correct design of the structures in seismic areas and the seismic inadequacy of a large part of the built heritage. Modern codes are still lacking in terms of prescriptions for the evaluation of the seismic performance of existing buildings. The present work proposes a simplified method for the evaluation of the demand in terms of plastic rotation for short links of steel Eccentrically Braced Frames (EBFs). A relationship for the evaluation of the demand, that exploits elastic analysis and rigid-plastic analysis extended to the second-order effects, is proposed. The calibration of this relationship was carried out on 420 EBFs equipped with short links designed according to three different approaches. The 420 frames have been also used to analyze the behavior in the plastic range of EBF type structures equipped with short links. The study also provides an extensive analysis on the influence of plastic redistribution capacity on the demand in terms of plastic rotations of links, corresponding to the achievement of the maximum bearing capacity. The obtained relation can be exploited as an assessment tool by comparing the demand with the link capacity. Moreover, from a performance-based design point of view, the same can be used for predicting the required ultimate plastic rotation as a function of the plastic redistribution capacity of the structure.

Novel Positioning Feedback System as a Guidance in Bone Tumor Resection.

Need: Bone resection using customized 3D-printed guides can improve accuracy, but the technique is still associated with clinically significant errors.Technical solution: We developed an inexpensive optical feedback system (OFS) that compares intraoperative 2D camera images to the pre-operative plan, and accurately depicts the surgeon's guide placement prior to cutting, reducing the errors in resection.Proof of concept: We simulated wide resections of a bone sarcoma on 24 cadaver femurs using 3 cutting guide types. Guide placement was measured using the OFS and compared to CT-scans showing the actual guide position. We carried out a second, controlled study on 20 sawbones, comparing the accuracy of the final bone cuts with and without the surgeon actively using the OFS to adjust the guide position before cutting.Results: For cadavers, in 2 of 3 planes, the position of the jig recorded by the OFS closely matched its actual position, with an accuracy of .87° ± .65°(r = .94) and 1.2° ± 1.3°(r = .81) in the transverse and sagittal planes, respectively. In the second study, OFS increased accuracy of the final cut about the transverse and sagittal planes, respectively by 53.1% (P = .011)/54.7% (P = .04) and 33% (P = .051)/38% (P = .042) in terms of rotation and translation.Next steps: Developing the OFS as a mobile application to reduce the processing time and improve accessibility in the operating room.Conclusion: The OFS could accurately depict the guide placement on the bone and significantly improve the surgical accuracy of 3D printed jigs.

Borates as a new direction in the design of oxide ion conductors

Lowering the operating temperature of solid oxide fuel cells (SOFCs) has extensively stimulated the development of new oxide ion conductors. Here, inspired by the structural commonalities of oxide ion conductors, the inability to accommodate oxygen vacancies in the rigid, isolated, 3-fold tetrahedral rings of SrSi/GeO3-based materials, and the considerable flexibility of BOn polyhedra in terms of coordination number, rotation, deformation, and linkage, we report the first borate-base family of oxide ion conductors, (Gd/Y)1−xZnxBO3−0.5x, through combined computational prediction and experimental verification. The oxygen vacancies in (Gd/Y)BO3 can be accommodated by forming B3O8 units in isolated, 3-fold, tetrahedral rings of B3O9 and transported through a cooperative mechanism of oxygen exchange between the B3O9 and B3O8 units, which is assisted by the intermediate opening and extending of these units. This study opens a new scientific field of the borate system for designing and discovering oxide ion conductors.

Twinning character and texture origination in the randomly-oriented AZ31B magnesium alloy during cold-rolling

Based on generalized Schmid factor (G-SF) calculation, the twinning character and texture development in the rolling plate of randomly-oriented AZ31B magnesium alloy were investigated in this work. The results showed that when the rolling reduction/nip angle is low, the twin type selection is independent of crystal orientation or G-SF due to the significant difference of critical resolved shear stress (CRSS) between extension twinning and contraction twinning. The twin variant selection does not intimately follow the Schmid criterion. In comparison, the extension twin variant selection departs more from the G-SF prediction than the contraction twin variant selection. The orientations of the matrix grains develop gradually tending to distribute around the normal direction (ND), which promote the activation of contraction twinning. The basal texture results only from the orientation development of the matrix grains, depending on the basal <a> slip and the pyramidal <c+a> slip, which was explained in terms of a crystal rotation by the dislocation interactions.

Microstructural study of microbands in a Fe-30Mn-6.5Al-0.3C low-density steel deformed at cryogenic temperature by combined electron channeling contrast imaging and electron backscatter diffraction

The microstructural characteristics of the microband (MB) structure in an austenitic Fe-30Mn-6.5Al-0.3C (wt.%) low-density steel tensile deformed at -196 °C were investigated by combined electron channeling contrast imaging and electron backscatter diffraction. The nucleation mechanisms and grain-orientation dependence of the most relevant microstructural features of the MB structure, namely, morphology, internal dislocation configuration, and alignment were quantitatively analyzed on the main texture components, i.e. <111>//tensile axis and <001>//tensile axis directions. The present study shows several unrevealed microstructural characteristics of MBs in austenitic Fe-Mn-Al-C low-density steels deformed at cryogenic temperatures. The analysis of the interplay between the activated slip systems and the microstructural characteristics of the MB structure provides further insight into the nucleation mechanisms and the boundary alignment. Several in-grain and grain boundary-assisted MB nucleation mechanisms were identified. At low strain levels (ε = 0.3), MB formation is controlled by planar slip localization phenomena acting on closely spaced slip bands. The MB structure is localized in the grain interiors of areas containing intense plastic localization. At high strain levels (ε = 0.6), the MB structure only develops in grains that are not favorable oriented for deformation twinning, i.e. grains oriented close to <001>//TA directions. At this deformation stage, the deformation behavior becomes highly inhomogeneous due to the activation of an in-grain macroscopic localization phenomenon associated with moderated lattice rotations (∼ 3–5°). It leads to the formation of a complex deformation structure formed by macroscopic deformation bands containing arrays of crystallographic MBs. The analysis of the MB alignment reveals several interesting features such as the formation of non-crystallographic MBs aligned along (3 -1 5) and (3 5 -1) planes. Their formation can be explained in terms of the lattice rotations accommodated by the active slip systems predicted by Winther's model.

The Physical Properties of the SVS 13 Protobinary System: Two Circumstellar Disks and a Spiraling Circumbinary Disk in the Making

We present Very Large Array (VLA) and Atacama Large Millimeter/submillimeter Array (ALMA) observations of the close (0.″3 = 90 au separation) protobinary system SVS 13. We detect two small circumstellar disks (radii ∼12 and ∼9 au in dust, and ∼30 au in gas) with masses of ∼0.004–0.009 M ☉ for VLA 4A (the western component) and ∼0.009–0.030 M ☉ for VLA 4B (the eastern component). A circumbinary disk with prominent spiral arms extending ∼500 au and a mass of ∼0.052 M ☉ appears to be in the earliest stages of formation. The dust emission is more compact and with a very high optical depth toward VLA 4B, while toward VLA 4A the dust column density is lower, allowing the detection of stronger molecular transitions. We infer rotational temperatures of ∼140 K, on scales of ∼30 au, across the whole source, and a rich chemistry. Molecular transitions typical of hot corinos are detected toward both protostars, being stronger toward VLA 4A, with several ethylene glycol transitions detected only toward this source. There are clear velocity gradients, which we interpret in terms of infall plus rotation of the circumbinary disk, and pure rotation of the circumstellar disk of VLA 4A. We measured orbital proper motions and determined a total stellar mass of 1 M ☉. From the molecular kinematics, we infer the geometry and orientation of the system, and stellar masses of ∼0.26 M ☉ for VLA 4A and ∼0.60 M ☉ for VLA 4B.

Comparison of Anterior and Posterior Kaltenborn Grade III Glide on Glenohumeral Joint for Improving External Rotation in Adhesive Capsulitis (Frozen Shoulder)

Background: Adhesive capsulitis is a common disabling and painful condition that causes limitation of both passive and active ranges of shoulder joint. Division of frozen shoulder can be into primary and secondary categories. Different techniques have been devised in physiotherapy to regain limited range of motion in adhesive capsulitis. Objectives: To compare the effects of anterior and posterior grade III Kaltenborn glides on glenohumeral joint for improving external rotation and functional ability in patients with adhesive capsulitis. Material and methods: This randomized controlled trial was conducted in University of Health Sciences, Lahore and 40 patients were recruited from Mayo Hospital, Lahore from 08-10-2019 to 10-02-2020 and divided randomly into two groups. Group A was given anterior glide and Group B was given posterior glide. Treatment was given for 4 weeks, 3 sessions in each week. Outcomes were measured in terms of external rotation and functional status of shoulder from Goniometry and SPADI scale. Results: Comparison of External rotation and SPADI score of group A (Anterior glider) and group B (posterior glide) has shown that both groups were similar at baseline (p&gt;0.05 for all variables) but post-treatment mean external rotation range in group A was 36.50 ± 7.72 while in group B was 52.80 ± 7.14, with the P value

New twists in compact binary waveform modeling: A fast time-domain model for precession

We present IMRPhenomTPHM, a phenomenological model for the gravitational wave signals emitted by the coalescence of quasi-circular precessing binary black holes systems. The model is based on the "twisting up" approximation, which maps non-precessing signals to precessing ones in terms of a time dependent rotation described by three Euler angles, and which has been utilized in several frequency domain waveform models that have become standard tools in gravitational wave data analysis. Our model is however constructed in the time domain, which allows several improvements over the frequency domain models: we do not use the stationary phase approximation, we employ a simple approximation for the precessing Euler angles for the ringdown signal, and we implement a new method for computing the Euler angles through the evolution of the spin dynamics of the system, which is more accurate and also computationally efficient.

Subacromial Spacer Implantation During Arthroscopic Partial Repair in Patients With Massive Irreparable Rotator Cuff Tears Provides Satisfactory Clinical and Radiographic Outcomes: A Retrospective Comparative Study

PurposeTo compare the clinical and radiographic outcomes of partial rotator cuff repair (RCR) with and without implantation of a biodegradable subacromial spacer in the treatment of symptomatic irreparable massive rotator cuff tears (MRCTs).MethodsPatients with MRCT who underwent arthroscopic partial repair alone (PR) or combined with subacromial spacer augmentation (PRS) were included. Patient-reported outcomes, including visual analog scale (VAS), American Shoulder and Elbow Surgeons (ASES), and Constant scores in addition to range of motion (ROM) were collected preoperatively and at the final follow-up. Additionally, we determined the percentages of all of the patients in groups that achieved the minimal clinical important difference (MCID), substantial clinical benefit (SCB), and patient-acceptable symptomatic state (PASS) for the VAS, ASES, and Constant scores. Acromiohumeral distance (AHD) was determined as well.ResultsA total of 32 patients were included. Group PR included 20 patients with a median age of 68 years (range: 64-73) and median follow-up 28.0 months (14.0-60.0). Group PRS included 12 patients with a median age of 68.5 years (range: 63-74) and median follow-up of 17.0 months (12.0-32.0). At the final follow-up, the ASES, VAS, and Constant scores were significantly higher in the PRS group (75.5 [55-88.3], 1.0 [0-3], and 70.0 [43-79], respectively, compared to the PR group (55.0 [37.5-65], 2.0 [0-4], and 55.0 [31-79], respectively; P < .05). The only statistically significant differences were found between the PR and PRS groups in terms of the proportions of the patients who achieved MCID for the ASES (70% vs. 100%; P = .04) and in terms of the proportions of the patients who achieved SCB for the ASES (60% vs 100%; P = .01) There was also statistically significant difference between the PR and PRS groups, in terms of the proportions of the patients who achieved PASS for the VAS and ASES ([30 % vs 66.7 %; P = .04] and [0 % vs 50 %; P = .001], respectively). AHD was also improved in the PRS group (8.4 [7-9.5] vs 7.85 [5.5-9]; P < .05). ROM was greater in the PRS group at final follow-up with median forward flexion degree, 140.0° (90°-150°) versus 120.0° (80°-153°) (P < .001) and median abduction degree, 100.0° (70°-130°) versus 90.0° (70°-110°). There was no difference in terms of external rotation between groups (3° [2°-5°] vs 3.0° (2°-4°); P = .4).ConclusionsArthroscopic partial RCR with implantation of a subacromial spacer leads to satisfactory clinical and radiographic outcomes in patients with symptomatic irreparable MRCT compared with patients treated with partial repair alone.Level of EvidenceLevel III, retrospective comparative study.

A Twin-jet Structure Rather than Jet Rotation in the Young Stellar Object OMC 2/FIR 6b

Abstract We analyze recent high-quality Atacama Large Millimeter Array (ALMA) molecular line mapping observations of the northeast jet of the young stellar object (YSO) OMC 2/FIR 6b (HOPS-60) and find that these ALMA observations are much more likely to indicate a twin-jet structure than jet rotation, as previously hypothesized. The interpretation of the line-of-sight velocity gradient across (perpendicular to its axis) the northeast jet of Fir 6b in terms of jet rotation leads to jet-launching radii of ≃2–3 au. However, the velocities of the jets ≃100–400 km s−1 are much larger than the escape speed from these radii. We argue that the northeast jet of FIR 6b is instead compatible with a twin-jet structure, as observed in some planetary nebulae. Specifically, we find that the main, redshifted jet emanating from the central YSO is composed of two, very closely aligned, narrower jets that were launched by the central YSO at about the same time but at different inclinations with respect to the plain of the sky. This twin-jet structure removes the extreme requirement that jets with velocities similar to the escape velocity from the YSO be launched from very large radii. The YSO FIR 6b and certain planetary nebulae also share the characteristics of unequal structures and intensities of their two opposing bipolar jets. We propose that such opposing lobe asymmetries can result from a substellar binary companion on an eccentric orbit that is inclined to the accretion disk plane.

Electrocardiographic QRS axis shift, rotation and COVİD-19.

In patients with coronavirus disease-2019 (COVID-19), severe dyspnea is the most dramatic complication. Severe respiratory difficulties may include electrocardiographic frontal QRS axis rightward shift (Rws) and clockwise rotation (Cwr). This study investigated the predictability of advanced lung tomography findings with QRS axis shift and rotation. This was a retrospective analysis of 160 patients. Patients were divided into the following two groups: normal (n = 80) and low (n = 80) oxygen saturation. These groups were further divided into four groups according to the rightward and leftward axis shift (Lws) on the electrocardiographic follow-up findings. These groups were compared in terms of electrocardiographic rotation (Cwr, counterclockwise rotation, or normal transition), tomographic stage (CO-RADS5(advanced)/CO-RADS1-4), electrocardiographic intervals, and laboratory findings. In patients with low oxygen saturation, the amount of QRS axis shift, Cwr, and tomographic stage were significantly higher in the Rws group than in the Lws group. There were no differences in the above parameters between the Rws and Lws groups in patients with normal oxygen saturation. Logistic regression analysis revealed that the presence of Cwr and Rws independently increased the risk of CO-RADS5 by 18.9 and 4.6 fold, respectively, in patients with low oxygen saturation. In COVID-19 patients who have dyspnea with low oxygen saturation, electrocardiographically clockwise rotation with a rightward axis shift demonstrated good sensitivity (80% [0.657-0.943]) and specificity (80% [0.552->1]) for predicting advanced lung tomographic findings. NCT04698083.

The interplay between fractional damping and nonlinear memory for the plate equation

In this paper, we study the interplay between a fractional damping (− Δ)θut with θ ∈ [0, 1/2), and a nonlinear memory term applied to a plate equation: in space dimension . In different scenarios, we prove the global existence of small data solutions in for supercritical powers, where the critical exponent is determined by the fractional power of the damping term and by the order of the fractional integration in the memory term. In one case, we also feel the influence of the regularity‐loss type decay, which is due to the presence of the rotational inertia term −Δutt in the plate equation.

On advantages of the “Substitute Frame” model for incremental dynamic analysis: Integration of speed and accuracy

The “Substitute Frame” (SF) model, which is a simplified MDOF system consisting of a one-bay multistory frame, has recently been introduced by the authors to predict the static and dynamic response of RC building frames, especially in terms of Interstory Drift Ratio (IDR) and plastic hinge rotation. It is known that incremental dynamic analysis (IDA) is one of the most accurate nonlinear seismic analyses that is of course a time-consuming method, having a high computational cost. Hence, this paper aims to focus on the accuracy and speed of the Substitute Frame (SF) as a simplified frame model in performing IDA, fragility analysis, and other probabilistic analyses. If the desired result is achieved, this can be promising to perform extensive probabilistic analysis efficiently. To this end, three 8-, 12-, and 20-story benchmark RC moment frames were selected and the corresponding simplified SF models were generated. To accurately perform the required analyses, the OpenSEES software by implementing modified Ibarra-Medina-Krawinkler springs with deteriorating peak-oriented behavior was used to apply Nonlinear Time-History Analysis (NTHA) using the Hunt-Fill algorithm for IDA analyses. The results showed that the SF model can be reliably applied to perform IDA analyses and developing fragility curves and it is computationally efficient and robust. The selected OpenSEES example files for the present study, are shared through the link “https://web.nit.ac.ir/~h.hamidi/software_data.htm”.