Lateral Zone Research Articles

Structural Analysis of Tunnel using FEA

Tunnels are typically built for transportation, such as roads, railways, or canals, but they can also be used for other purposes, such as mining, sewerage, or water supply. Tunnels allow us to travel safely and efficiently through difficult terrain, and they provide us with access to essential resources such as water and energy. The objective of current research is to evaluate the structural characteristics of tunnel structure under geo-mechanical loading conditions. The structural analysis of tunnel is conducted using techniques of FEA. The CAD modelling and FEA simulation of tunnel is conducted using ANSYS simulation package. The shear stress, normal stress and deformation data are generated. From the generated data, the critical regions are identified and the lateral zone of tunnel is one of them. This region is likely to induce damage in the form of crack.

Rayleigh phase velocity and azimuthal anisotropy from ambient noise data in the Sanjiang lateral collision zone in the SE margin of the Tibetan plateau

The Sanjiang lateral collision zone in the SE margin of the Tibetan Plateau is located at the east edge of the junction of the Eurasian and Indian plates. Using the continuous seismic waveforms recorded by 146 temporary and 21 permanent seismic stations in the study area, we obtain Rayleigh wave phase velocity and azimuthal anisotropy for periods 2 s to 40 s from the surface wave direct tomography method. This direct tomography method can obtain finer high-resolution results than the traditional surface wave tomography. Our results show that the low-velocity anomalies are found beneath the Lijiang-Xiaojinhe fault (LXF), Red River fault (RRF), Chuxiong fault and Tengchong volcanoes, the high-velocity anomalies are in the region of Weixi and Panzhihua at periods 5 ~ 8 s. The fast velocity directions mainly align N-S. At periods 10 ~ 15 s, the distributions of low-velocity anomalies are consistent with the strikes of LXF and RRF. At periods 20 ~ 35 s, the high- and low-velocity anomalies are bounded by the RRF, which may imply the fault is divided by the thick crust (indicated by low-velocity anomalies) and the thin crust with shallow mantle (indicated by high-velocity anomalies). The fast velocity directions at the periods 10 ~ 35 s rotate clockwise from north to south of the study area. The intensity of anisotropy in the low-velocity zone is stronger than that in the high-velocity zone, and the intensity in the north of the study area is stronger than that in the south. Results indicate the source of anisotropy may be different in each subzone.

Seismic Anisotropy in the upper crust beneath the Sanjiang lateral collision zone in the southeastern margin of the Tibetan Plateau revealed by S wave splitting from a temporary array

The Sanjiang lateral collision zone is a key region to understand the Tibetan Plateau’s tectonic structure and the Tethys-Himalayan’s tectonic evolution. Complex tectonic structures, intense crustal deformation, frequent seismicity, and abundant metal deposits are all present. With the seismic data recorded by a temporary array (SJ-Array) and permanent stations (Nov. 2018 ~ Dec. 2020), this paper adopts the S wave splitting technique to obtain the essential properties of upper crustal anisotropy. In the interested area, it is shown that the dominant polarization of the fast S wave is NNW, with a mean polarization direction of 167.9°. In addition, the study area can be divided into three subzones from the west to the east: A, B, and C, according to the various mean polarizations varying from NNW, NS to NNE. The mean normalized time delay between the two split S waves is 4.0 ms/km, and the range of time delay is from 2.0 to 6.3 ms/km. The largest time delay is located at the east side of the western boundary of the Sichuan-Yunnan rhombus block. Furthermore, there is a strip area of strong anisotropy stretching along the western segment of the Lijiang-Xiaojinhe fault. These all demonstrate the local tectonic differences and indicate that the crustal structure may be strongly controlled by the fault and block boundary strike.

Feasibility of C2 Pedicle Screw Fixation With the "in-out-in" Technique for Patients With Basilar Invagination.

Retrospective study. To evaluate the feasibility of C2 pedicle screw fixation with the "in-out-in" technique in patients with basilar invagination (BI). The "in-out-in" technique is a fixation technique in which the screw enters the vertebrae through the parapedicle. The technique has been used in upper cervical spine fixation. However, anatomic parameters associated with the application of this technique in patients with BI are unclear. We measured the C2 pedicle width (PW), the distance between the vertebral artery (VA) and the transverse foramen (VATF), the safe zone, and the limit zone. The lateral safe zone is the distance from the medial/lateral cortex of the C2 pedicle to the VA (LPVA/MPVA), and the medial safe zone is the distance from the medial/lateral cortex of the C2 pedicle to the dura (MPD/LPD). The lateral limit zone is the sum of LPVA/MPVA and VATF (LPTF/MPTF), and the medial limit zone is the distance from the medial/lateral cortex of the C2 pedicle to the spinal cord (MPSC/LPSC). PW, LPVA, MPVA, and VATF were measured on the reconstructed CT angiography. PW, MPD, LPD, MPSC, and LPSC were measured on MRI. We define a width greater than 4mm as safe for screw. The t -test was used to compare the parameters between male and female, left and right sides in all patients, and PW in CTA and MRI data in the same patient. For intrarater reliabilities, interclass correlation coefficients were calculated. A total of 154 patients (49 CTA, 143 MRI) were included. The average PW, LPVA, MPVA, LPTF, MPTF, MPD, LPD, MPSC, and LPSC were 5.30mm, 1.28mm, 6.60mm, 2.45mm, 8.94mm, 2.09mm, 7.07mm, 5.51mm, and 10.48mm, respectively. Furthermore, in patients with PW <4mm, 53.6% of MPVA, 86.2% of LPTF, and all limit zones were larger than 4mm. In patients with BI, there is sufficient space medially and laterally to the C2 pedicle for partial screw encroachment to achieve "in-out-in" fixation, even if the pedicle is small. Level-4.

In vivo evaluation of ankle kinematics and tibiotalar joint contact strains using digital volume correlation and 3 T clinical MRI

BackgroundIn vivo evaluation of ankle joint biomechanics is key to investigating the effect of injuries on the mechanics of the joint and evaluating the effectiveness of treatments. The objectives of this study were to 1) investigate the kinematics and contact strains of the ankle joint and 2) to investigate the correlation between the tibiotalar joint contact strains and the prevalence of osteochondral lesions of the talus distribution. MethodsEight healthy human ankle joints were subjected to compressive load and 3 T MRIs were obtained before and after applying load. The MR images in combination with digital volume correlation enabled non-invasive measurement of ankle joint kinematics and tibiotalar joint contact strains in three dimensions. FindingsThe total translation of the calcaneus was smaller (0.48 ± 0.15 mm, p < 0.05) than the distal tibia (0.93 ± 0.16 mm) and the talus (1.03 ± 0.26 mm). These movements can produce compressive and shear joint contact strains (approaching 9%), which can cause development of lesions on joints. 87.5% of peak tensile, compressive, and shear strains in the tibiotalar joint took place in the medial and lateral zones. InterpretationThe findings suggested that ankle bones translate independently from each other, and in some cases in opposite directions. These findings help explain the distribution of osteochondral lesions of the talus which have previously been observed to be in medial and lateral regions of the talar dome in 90% of cases. They also provide a reason for the central region of talar dome being less susceptible to developing osteochondral lesions.

Predictors of atrial flutter recurrence after atrial fibrillation ablation: the crucial role of structural and morphological left atrial remodeling

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Unrestricted Grant - Abbott Medical Introduction Recurrence of supraventricular tachyarrhythmias after catheter ablation of atrial fibrillation (AF) is common, representing 30% of patients. Although AF recurrence occurs mostly, 10% of the patients face arrhythmia recurrence through atypical atrial flutter (AFL). The diagnostic and therapeutic management of atypical AFL is challenging. Predicting atypical AFL after AF catheter ablation is critical. Purpose To identify morphological and structural predictors of recurrence in the form of atypical AFL compared to AF based on Late Gadolinium Enhancement Cardiac Magnetic Resonance (LGE-CMR). Methods – From January 2013 to December 2021, 56 patients facing post AF-CA atypical AFL were included in the monocentric and retrospective cohort. 112 patients with AF recurrence were randomly included in the cohort from the general database. Pre-procedure LGE-CMR was post-processed for every patient to assess global and regional left and right atrial (LA, RA) fibrosis quantification using an image intensity ratio &amp;gt; 1.32 as fibrosis. Sphericity was calculated as the percentage of similarity with respect to a sphere, and the volume of LA and RA were calculated. Results – 168 patients who had faced supraventricular arrhythmia recurrence after AF-CA were included in the monocentric retrospective cohort. They were mainly male (72.1%), with a median CHADS-VASc score of 1.4 +/- 1.3, a number of previous CA of 2,2 +/- 0.4, and a biatrial dilation (LA volume index of 53.5 ml/m2, RA volume index of 59.6 ml/m2). An age superior to 65 (OR=6.61, CI95%:2.18-14.41, p&amp;lt;0.01), the number of previous CA procedures (OR=3.03, CI95%:1.17-7.81, p=0.02), a history of management of invasive additional lines (OR=2.48, CI95%:1.01-6.27, p=0.05), an elevated LA sphericity (OR=1.33, CI95%:1.11-1.59, p&amp;lt;0.01) and an increased LA fibrotic burden (OR=1.03, CI95%:1.00-1.07, p=0.04) independently predicted the occurrence of atypical AFL compared with AF recurrence after AF-CA (Figure 1). Specifically, an increased amount of fibrosis in the lateral LA zone area (OR=1.03, CI95%:1.01-1.04, p&amp;lt;0.01)] was an independent predictor of recurrence in the form of atypical AFL compared with AF recurrence (Figure 2). Conclusion The structural LA remodeling of AE, including LA fibrosis and LA sphericity, is a predictor of recurrence in the form of atypical atrial flutter compared with AF recurrence after AF-CA.

Size regulation of the lateral organ initiation zone and its role in determining cotyledon number in conifers.

Unlike monocots and dicots, many conifers, particularly Pinaceae, form three or more cotyledons. These are arranged in a whorl, or ring, at a particular distance from the embryo tip, with cotyledons evenly spaced within the ring. The number of cotyledons, nc, varies substantially within species, both in clonal cultures and in seed embryos. nc variability reflects embryo size variability, with larger diameter embryos having higher nc. Correcting for growth during embryo development, we extract values for the whorl radius at each nc. This radius, corresponding to the spatial pattern of cotyledon differentiation factors, varies over three-fold for the naturally observed range of nc. The current work focuses on factors in the patterning mechanism that could produce such a broad variability in whorl radius. Molecularly, work in Arabidopsis has shown that the initiation zone for leaf primordia occurs at a minimum between inhibitor zones of HD-ZIP III at the shoot apical meristem (SAM) tip and KANADI (KAN) encircling this farther from the tip. PIN1-auxin dynamics within this uninhibited ring form auxin maxima, specifying primordia initiation sites. A similar mechanism is indicated in conifer embryos by effects on cotyledon formation with overexpression of HD-ZIP III inhibitors and by interference with PIN1-auxin patterning. We develop a mathematical model for HD-ZIP III/KAN spatial localization and use this to characterize the molecular regulation that could generate (a) the three-fold whorl radius variation (and associated nc variability) observed in conifer cotyledon development, and (b) the HD-ZIP III and KAN shifts induced experimentally in conifer embryos and in Arabidopsis. This quantitative framework indicates the sensitivity of mechanism components for positioning lateral organs closer to or farther from the tip. Positional shifting is most readily driven by changes to the extent of upstream (meristematic) patterning and changes in HD-ZIP III/KAN mutual inhibition, and less efficiently driven by changes in upstream dosage or the activation of HD-ZIP III. Sharper expression boundaries can also be more resistant to shifting than shallower expression boundaries. The strong variability seen in conifer nc (commonly from 2 to 10) may reflect a freer variation in regulatory interactions, whereas monocot (nc = 1) and dicot (nc = 2) development may require tighter control of such variation. These results provide direction for future quantitative experiments on the positional control of lateral organ initiation, and consequently on plant phyllotaxy and architecture.

Strigolactone Mediates Moso Bamboo Root Response to Phosphate Stress.

Both phosphate (Pi) deficiency and high Pi significantly affect moso bamboo growth and degrade bamboo forests. A novel plant hormone, strigolactone (SL), plays a crucial role in root growth under low Pi, but the SL regulatory mechanism has not been systematically reported in moso bamboo. In our study, we investigated the SL-mediated root growth mechanism in response to Pi stress in moso bamboo. With the decrease of the Pi level, 5-deoxystrigol and strigol significantly increased in the root exudates. Transcriptome sequencing of the primary root tip and lateral root primordium zone (LRP) under low, sufficient, and high Pi indicated that SL-biosynthesis and -signaling changes are part of the early root responses. The effects of the SL analogue (rac-GR24) and SL inhibitor (TIS108) on the root architecture under low and high Pi revealed that SL mediates bamboo root responses by regulating its biosynthesis and signal transduction and influencing other hormone pathways.

PO-02-197 PREDICTORS OF ATRIAL FLUTTER RECURRENCE AFTER ATRIAL FIBRILLATION ABLATION: THE CRUCIAL ROLE OF STRUCTURAL AND MORPHOLOGICAL LEFT ATRIAL REMODELING

Recurrence of supraventricular tachyarrhythmias after catheter ablation of atrial fibrillation (AF) is common, representing 30% of patients. Although AF recurrence occurs mostly, 10% of the patients face arrhythmia recurrence through atypical atrial flutter (AFL). The diagnostic and therapeutic management of atypical AFL is challenging. Predicting atypical AFL after AF catheter ablation is critical. To identify morphological and structural predictors of recurrence in the form of atypical AFL compared to AF based on Late Gadolinium Enhancement Cardiac Magnetic Resonance (LGE-CMR). From January 2013 to December 2021, 56 patients facing post-AF-CA atypical AFL were included in the monocentric and retrospective cohort. 112 patients with AF recurrence were randomly included in the cohort from the general database. Pre-procedure LGE-CMR was post-processed for every patient to assess global and regional left and right atrial (LA, RA) fibrosis quantification using an image intensity ratio > 1.32 as fibrosis. Sphericity was calculated as the percentage of similarity with respect to a sphere, and the volume of LA and RA were calculated. 168 patients who had faced supraventricular arrhythmia recurrence after AF-CA were included in the monocentric retrospective cohort. They were mainly male (72.1%), with a median CHADS-VASc score of 1.4 +/- 1.3, a number of previous CA of 2,2 +/- 0.4, and a biatrial dilation (LA volume index of 53.5 ml/m2, RA volume index of 59.6 ml/m2). An age superior to 65 (OR=6.61, CI95%:2.18-14.41, p<0.01), the number of previous CA procedures (OR=3.03, CI95%:1.17-7.81, p=0.02), a history of management of invasive additional lines (OR=2.48, CI95%:1.01-6.27, p=0.05), an elevated LA sphericity (OR=1.33, CI95%:1.11-1.59, p<0.01) and an increased LA fibrotic burden (OR=1.03, CI95%:1.00-1.07, p=0.04) independently predicted the occurrence of atypical AFL compared with AF recurrence after AF-CA (Figure). Specifically, an increased amount of fibrosis in the lateral LA zone area (OR=1.03, CI95%:1.01-1.04, p<0.01)] was an independent predictor of recurrence in the form of atypical AFL compared with AF recurrence (Table). The structural LA remodeling of AE, including LA fibrosis and LA sphericity, is a predictor of recurrence in the form of atypical atrial flutter compared with AF recurrence after AF-CA.

Fin systems comparative anatomy in model Batoidea Raja asterias and Torpedo marmorata: Insights and relatioships between musculo-skeletal layout, locomotion and morphology.

The macroscopic and microscopic morphology of the appendicular skeleton was studied in the two species Raja asterias (order Rajiformes) and Torpedo marmorata (Order Torpediniformes), comparing the organization and structural layout of pectoral, pelvic, and tail fin systems. The shape, surface area and portance of the T. marmorata pectoral fin system (hydrodynamic lift) were conditioned by the presence of the two electric organs in the disk central part, which reduced the pectoral fin surface area, suggesting a lower efficiency of the "flapping effectors" than those of R. asterias. Otherwise, radials' rays alignment, morphology and calcification pattern showed in both species the same structural layout characterized in the fin medial zone by stiffly paired columns of calcified tiles in the perpendicular plane to the flat batoid body, then revolving and in the horizontal plane to continue as separate mono-columnar rays in the fin lateral zone with a morphology suggesting fin stiffness variance between medial/lateral zone. Pelvic fins morphology was alike in the two species, however with different calcified tiles patterns of the 1st compound radial and pterygia in respect to the fin-rays articulating perpendicularly to the latter, whose tile rows lay-out was also different from that of the pectoral fins radials. The T. marmorata tail-caudal fin showed a muscular and connective scaffold capable of a significant oscillatory forward thrust. On the contrary, the R. asterias dorsal tail fins were stiffened by a scaffold of radials-like calcified segments. Histomorphology, heat-deproteination technique and morphometry provided new data on the wing-fins structural layout which can be correlated to the mechanics of the Batoid swimming behavior and suggested a cartilage-calcification process combining interstitial cartilage growth (as that of all vertebrates anlagen) and a mineral deposition with accretion of individual centers (the tiles). The resulting layout showed scattered zones of un-mineralized matrix within the calcified mass and a less compact texture of the matrix calcified fibers suggesting a possible way of fluid diffusion throughout the mineralized tissue. These observations could explain the survival of the embedded chondrocytes in absence of a canalicular system as that of the cortical bone.

Alignment and Fixation in Revision Total Knee Arthroplasty With Press-Fit, Offset, Diaphyseal-Engaging Stem Extensions, and Eccentric Reaming Technique

BackgroundA revision total knee arthroplasty must control limb alignment, often to address the cause of failure. Press-fit stems that engage the diaphysis with cement restricted to the metaphysis constitute one fixation technique. These long stems restrict coronal alignment of the prosthesis and as a result reduce the likelihood of extreme malposition. For the same reasons, long stems can make it difficult to manipulate alignment and achieve a specific coronal alignment angle. Nevertheless, femoral stems with a tight diaphyseal fit may still occupy a small range of varus-valgus positions due to the conical distal femoral metaphysis. Pulling the reamer toward the lateral endosteum increases femoral component coronal alignment toward a valgus direction and pushing the reamer medially increases alignment in a more varus direction. A straight stem, in combination with a medially directed reaming, would result in a femoral component that overhangs medially, but an offset stem can recenter the femoral component and maintain the desired alignment. We hypothesized that diaphyseal fit plus this reaming technique can control limb coronal alignment and provide fixation. MethodsThis was a retrospective clinical and long-leg radiographic study of consecutive revision total knee arthroplasties with minimum 2-year follow-up. Outcomes were correlated with New Zealand Joint Registry data to identify rerevisions of 111 consecutive revision knee arthroplasties, 92 after exclusions, at a minimum 2-year (range, 2 to 10) follow-up. ResultsMean femoral and tibial canal fill exceeded 91% on antero-posterior and lateral radiographs. The mean hip-knee-ankle angle was 179.6o (174.9-184.0) with 80% within ± 3o of neutral. The hip-ankle axis crossed the central Kennedy zone in 76.5% of cases and the other 24.6% crossed the inner medial and inner lateral zones. Tibial components: 99.0% ± 3o. Femoral components: 89.5% within ± 3o. There were 5 knees that failed due to infection, 3 from femoral loosening, and 1 due to recurvatum instability from polio. ConclusionsThis study describes a surgical plan and technique for achieving target coronal alignment with press-fit diaphyseal fixation. It is the only series of revision knee arthroplasties with diaphyseal press-fit stems to report canal fill in 2 planes and coronal alignment on full-length radiographs.

Serial Quantitative Assessment of Load Redistribution After Medial Open-Wedge High Tibial Osteotomy.

The maximum standardized uptake value (SUVmax), as determined on combined single-photon emission computed tomography and conventional computed tomography (SPECT/CT), can be an indicator of biomechanical changes due to the load redistribution effect after medial open-wedge high tibial osteotomy (MOW-HTO). The purposes of this study were to (1) analyze serial changes in the SUVmax in the medial, lateral, and patellofemoral compartments after MOW-HTO and (2) identify the contributing factors that affect changes in the SUVmax. The hypotheses were that (1) an elevated SUVmax in the medial compartment would be transferred to the lateral compartment because of the load redistribution effect and (2) there would be contributing factors that cause SUVmax changes. Case series; Level of evidence, 4. Included were 67 knees that were treated with biplanar MOW-HTO between March 2019 and December 2020. SPECT/CT was performed immediately after surgery and at 3 months and 1 year postoperatively to determine the serial load redistribution effect of MOW-HTO. The Pearson correlation coefficient was used to evaluate the relationship between SUVmax and radiological parameters, and subgroup analyses were conducted to compare the SUVmax according to associated cartilage procedures and the weightbearing line ratio (WBLR). The SUVmax in the medial and lateral compartments increased at 3 months but decreased at 1 year postoperatively. The load redistribution effect was most prominent in the anterior zones of the femur (medial: P = .041; lateral: P = .012). In the patella, the SUVmax decreased in both the medial and the lateral zones at all follow-up times (P < .001 for all). The SUVmax in the anterolateral and posterolateral articular zones of the femur increased with a greater preoperative WBLR (r = 0.256, P = .039; and r = 0.261, P = .036, respectively). Patients who underwent an associated cartilage procedure had a significantly higher SUVmax in the anteromedial and posteromedial articular zones of both the femur and the tibia at 1 year postoperatively (P ≤ .002 for all). After MOW-HTO, the unloading effect in the anteromedial articular zone of the femur was the most significant. A greater SUVmax in the lateral zones of the femur was observed in cases of overcorrection. The SUVmax in the medial zones was higher postoperatively in patients with associated cartilage procedures.

The Rib Fracture Map in Patients with High-Energy Mechanisms of Injury.

The objective of this study was to use a novel rib unfurling technology to investigate the locations of multiple rib fractures occurring from high-energy trauma to discern if there are reproducible rib fracture patterns. Patients between the ages of 18 and 48 presenting to a Level 1 academic trauma center with ≥ 2 rib fractures following a high-energy mechanism of injury between 2017 and 2019 were identified. Curved planar reformatting of CT scans was used to create two-dimensional unfurled rib images by flattening out the view of the ribs from a CT scan. Rib fractures were placed on a template map using a standardized measurement method and subsequent frequency and heat maps were created. Among 100 consecutive patients, 534 fractures on 454 ribs were identified. The most common high-energy mechanism of injury was motor vehicle accidents (41%). Flail chest occurred in 8% of patients. The mean number of ribs fractured per patient was 4.54 ± 3.14 and included a mean of 5.34 ± 4.38 total fractures. Among all fractures, 50.9% were located on ribs 4 through 7. The most common fracture location was located in the lateral or anterolateral zone of the ribcage. Patients with multiple rib fractures from high-energy trauma have rib fractures with locations of common occurrence. An understanding of location and frequency of rib fractures can help inform surgical approaches, prognosis, indications, classifications, and implant design in the management of a complex population of patients with chest wall injury following trauma. Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Cavernous Malformations: What They Have Taught Us.

Cavernous Malformations: What They Have Taught Us.

Numerical study on the lateral soil arching effect and associated tunnel responses behind braced excavation in clayey ground

This study uses numerical simulation to investigate the soil arching effect behind a braced excavation in clayey ground and derive an insight into the mechanisms behind the nearby tunnel responses. The numerical results are validated by field measurements of a well-documented case history. It is found that the lateral excavation-induced loosened zone is located behind the position with maximum wall deformation. The arching zone develops above the loosened zone and the stable zone is formed at the peripheral. Ground stress is transferred from the loosened zone to the adjoining stable zone and arching zone. The stress transfer along the arching zone drags the soil against the bracing and increases the lateral earth pressure around the upper part of the wall, where the soil is in passive stress state. The stress transfer along the shear plane increases the lateral earth pressure within the stable zone, where the soil is also in a passive state. The stress transfer induced by the minor principal stress arching in the loosened zone increases the radial load on the tunnel crown for the tunnel located entirely in the loosened zone. In addition, the tunnel deformation and bending moment associated with the arching effect are discussed.

Classification of Endoscopic Transnasal Lateral Skull Base Approaches: Anatomical Study

Endoscopic transnasal approaches (ETAs) to the ventrolateral skull base are commonly classified according to coronal planes or anatomical structures. Our goal is to simplify the description of the ETA to lateral skull base regions in a sequential dissection with correlation to computed tomography, helping in preoperative planning and efficient surgical exposure, and exposing the surgical anatomy limitations. Five freshly injected cadaver heads were dissected using an extended ETA to the lateral skull base. Each specimen underwent a high-resolution computed tomography scan. A classification of the lateral skull base based on well-defined zones was proposed. We divided the lateral target into four different zones, in a craniocaudal orientation: zone 1 is the space lying between the orbital floor superior and the level of the sellar floor inferior, zone 2 is on the coronal plane, located between the level of the sellar floor and the vidian canal, zone 3 is the area lateral to the anterior limb of the petro-occipital fissure, located between the vidian canal and the carotid canal, and zone 4 is the space located between the carotid canal and the extracranial opening of the hypoglossal canal, lateral to the anterior part of the posterior limb of petro-occipital fissure. Multiple previous works have described and classified the coronal plane and its lateral extensions. Our classification system for the proposed lateral zones enables preoperative planning to select a suitable approach. The craniocaudal orientation facilitates the understanding of surgical corridors and tailored exposure.

Crustal azimuthal anisotropy in the lateral collision zone of the SE margin of the Tibetan Plateau and its tectonic implications

SUMMARYResolving the detail of crustal deformation of the seismically and technically active Sichuan-Yunnan block located in the southeast margin of the Tibetan Plateau is crucial for understanding the lateral extrusion of the Tibetan Plateau. Using seismic data from two regional seismograph stations of the China Earthquake Networks Center and twenty recently deployed broad-band temporary stations from the MCD Array (Middle ChuanDian block seismic array), we constrained crustal thickness and seismic anisotropy at the west boundary of the Sichuan-Yunnan block, near the east Himalayan syntaxis by receiver function techniques including CCP stacking and sinusoidal moveout of PmS conversions. Crustal thickness varies significantly across major faults inside the block which increases by &amp;gt;20 km from west to east. East of the Chenghai Fault, a clear positive phase lies above the Moho and is interpreted to be caused by the magma intrusion related to a late Permian Emeishan large igneous province (ELIP). The crustal anisotropy shows strong zoning features and clockwise rotation with respect to due north. To the west of the Lijiang-Xiaojinhe and the Honghe Faults, anisotropic fast orientations are near NS, indicating strong crustal deformation and movement of southward crustal flow along the Nujiang-Lancangjiang Fault; to the east of this fault, anisotropic fast orientations are near NE. The variation of the anisotropic fast orientations indicates that the southeastward crustal flow from the Tibetan Plateau may be prevented by fast velocity anomalies beneath the ELIP. These observations provided new evidence for strong crustal deformation along the tectonic boundary in the southeastern Tibetan Plateau with the expansion of the Tibetan Plateau.

New method of surgical treatment of glaucoma

Background. Fistulizing operations are the most commonly used types of surgery for both primary and secondary glaucoma. The development of cicatricial blockade in the area of surgical intervention is considered one of the reasons for the decrease in the hypotensive effect of surgical treatment of glaucoma, for which antiglaucoma drainages are widely used.&#x0D; Aim. To evaluate the hypotensive efficacy of sinustrabeculectomy with implantation of drainage from collagen hemostatic sponge using Maklakov tonometry and quality of life indicators in patients with primary open-angle glaucoma in the course of surgical treatment.&#x0D; Material and methods. The study involved 52 people (52 eyes) (mean age 64.14.4 years) with a diagnosis of primary open-angle glaucoma. The inclusion criteria were the age of 4080 years, the diagnosis of glaucoma for more than 6 months, the ineffectiveness of local drug therapy, and the absence of severe concomitant ophthalmic pathology. All patients underwent surgical treatment of glaucoma: sinustrabeculectomy with posterior scleral trepanation and implantation of drains in the form of 42.5 mm strips from a collagen hemostatic sponge under the scleral flap in three zones: in the distal and lateral zones of the flap. In the postoperative period, the level of intraocular pressure was assessed on the 30th, 90th and 180th days. The patients' quality of life was assessed using the GQL-15 questionnaire. Statistical processing of materials was carried out using the Statistica 8.0 software package (Statsoft, Inc., USA), comparison in dynamics was carried out using Student's parametric t-test. The normality of the sample distribution was controlled using the ShapiroWilk test. Significance of differences in indicators was considered established at a significance level of p 0.05.&#x0D; Results. The surgical treatment of patients contributed to a decrease in intraocular pressure from 42.46.5 to 13.44.9 mm Hg (p=0.0000) and improved quality of life according to the GQL-15 questionnaire from 28.64.3 to 19.31.9 points (p=0.0224) on day 30 after surgery. During the observation period, the level of intraocular pressure remained within the normal range, amounting to 16.94.3 mm Hg on the 90th day, and 18.14.6 mm Hg on the 180th day.&#x0D; Conclusion. The modified method for the treatment of glaucoma leads to a long-term (6 months) effective reduction in intraocular pressure in patients and an improvement in their quality of life.

Multi-side Digital Image Correlation (DIC) evaluation of CFRP bonded to poplar timber

Digital Image Correlation (DIC) is a technique that permits full analysis of the strain field distribution upon the surface of solids. The nonlinear bonding interaction between poplar timber and CFRP (Carbon Fiber Reinforced Polymers) reinforcement under mixed mode I&II is analyzed. The test setup inserts an eccentric axial load and a corresponding bending moment. The experiments show strain distributions composed of two lateral transfer zones in which bonding mode II predominates and, a central zone of constant strain in which bonding mode I is dominant. The maximum load capacity increases with the bond length until the effective bond length.

Lung ultrasound to evaluate aeration changes in response to recruitment maneuver and prone positioning in intubated patients with COVID-19 pneumonia: preliminary study

BackgroundThis single-center preliminary prospective observational study used bedside ultrasound to assess the lung aeration modifications induced by recruitment maneuver and pronation in intubated patients with acute respiratory disease syndrome (ARDS) related to coronavirus 2019 disease (COVID-19).All adult intubated COVID-19 patients suitable for pronation were screened. After enrollment, patients underwent 1 h in a volume-controlled mode in supine position (baseline) followed by a 35-cmH2O-recruitment maneuver of 2 min (recruitment). Final step involved volume-controlled mode in prone position set as at baseline (pronation). At the end of the first two steps and 1 h after pronation, a lung ultrasound was performed, and global and regional lung ultrasound score (LUS) were analyzed. Data sets are presented as a median and 25th–75th percentile.ResultsFrom January to May 2022, 20 patients were included and analyzed. Global LUS reduced from 26.5 (23.5–30.0) at baseline to 21.5 (18.0–23.3) and 23.0 (21.0–26.3) at recruitment (p < 0.001) and pronation (p = 0.004). In the anterior lung regions, the regional LUS were 1.8 (1.1–2.0) following recruitment and 2.0 (1.6–2.2) in the supine (p = 0.008) and 2.0 (1.8–2.3) in prone position (p = 0.023). Regional LUS diminished from 2.3 (2.0–2.5) in supine to 2.0 (1.8–2.0) with recruitment in the lateral lung zones (p = 0.036). Finally, in the posterior lung units, regional LUS improved from 2.5 (2.3–2.8) in supine to 2.3 (1.8–2.5) through recruitment (p = 0.003) and 1.8 (1.3–2.2) with pronation (p < 0.0001).ConclusionsIn our investigation, recruitment maneuver and prone positioning demonstrated an enhancement in lung aeration when compared to supine position, as assessed by bedside lung ultrasound.Trial registration: www.clinicaltrials.gov, Number NCT05209477, prospectively registered and released on 01/26/2022.