Superior-inferior Research Articles

Planar biaxial testing of CXL strengthening effects

The stiffening effect of corneal crosslinking (CXL) treatment, a therapeutic approach for managing the progression of keratoconus, has been primarily investigated using uniaxial tensile experiments. However, this testing technique has several drawbacks and is unable to measure the mechanical response of cornea under a multiaxial loading state. In this work, we used biaxial mechanical testing method to characterize biomechanical properties of porcine cornea before and after CXL treatment. We also investigated the influence of preconditioning on measured properties and used TEM images to determine microstructural characteristics of the extracellular matrix. The conventional method of CXL treatment was used for crosslinking the porcine cornea. The biaxial experiments were done by an ElectroForce TestBench system at a stretch ratio of 1:1 and a displacement rate of 2 mm/min with and without preconditioning. The experimental measurements showed no significant difference in the mechanical properties of porcine cornea along the nasal temporal (NT) and superior inferior (SI) direction. Furthermore, the CXL therapy significantly enhanced the mechanical properties along both directions without creating anisotropic response. The samples tested with preconditioning showed significantly stiffer response than those tested without preconditioning. The TEM images showed that the CXL therapy did not increase the diameter of collagen fibers but significantly decreased their interfibrillar spacing, consistent with the mechanical property improvement of CXL treated samples.

Norm Conflicts on Criminal and Administrative Sanctions in Forestry Law

This research is motivated by obstacles in the law enforcement process due to conflicts between government regulations and laws in the application of criminal and administrative sanctions in the forestry sector. The method used in this research is a normative legal research method with a statutory approach and a conceptual approach. The purpose of this research is to analyze and provide solutions to the norm conflict between Article 18 paragraphs (1) and (2) of the Republic of Indonesia Law No. 6 of 2023 concerning the Government Regulation in Lieu of Law (Perppu) No. 2 of 2022 on Job Creation, which has been enacted into law, and the Government Regulation of the Republic of Indonesia No. 24 of 2021 on the Procedures for Imposing Administrative Sanctions and Procedures for Non-Tax State Revenue Derived from Administrative Fines in the Forestry Sector. The research findings indicate that based on the principle of lex superior derogate lex inferior, the applicable provisions are Article 18 paragraphs (1) and (2) of the Republic of Indonesia Law No. 6 of 2023, which states that criminal and administrative sanctions are imposed cumulatively. Therefore, Government Regulation No. 24 of 2021, which states that criminal sanctions are not imposed, must be set aside. To resolve this norm conflict, several steps can be taken, including legal interpretation by the Supreme Court, consultation and negotiation between legislative and executive bodies, revision and amendment of regulations by executive or legislative bodies, court intervention by the Supreme Court or the Constitutional Court, and regulation by independent bodies through the National Legislation Agency in Indonesia. This research provides recommendations to the government to formulate government regulations that do not conflict with laws to ensure an unhindered law enforcement process and achieve legal certainty, justice, and utility.

Comparative Analysis of Mechanical Thrombectomy Outcomes of Middle Cerebral Artery M1, M2 Superior, and M2 Inferior Occlusion Strokes

BackgroundThe M1 middle cerebral artery (MCA) commonly bifurcates into an M2 superior and an M2 inferior segment. However, MCA anatomy is highly variable rendering classification for mechanical thrombectomy (MT) trials difficult. Safety and effectiveness of M2 MCA stroke thrombectomy stratified by M2 MCA anatomy remains to be explored. MethodsLarge vessel occlusion strokes undergoing MT between 02/2016-08/2022 were reviewed (n=784). M1 (n=431) and M2 MCA (n=118) occlusions were assessed. Among M2 MCA occlusions only prototypical MCA bifurcation anatomy cases were included (n=99). Dominance was assessed based on angiography. Procedural and outcome data was compared between M1, M2 superior and M2 inferior MCA occlusions. ResultsBaseline demographics and periprocedural criteria of M2 superior (n=56) and M2 inferior (n=43) occlusion MTs were comparable. Among M2 inferior cases, the occluded branch was dominant in 41/43 (95.3%) but only in 37/56 (66.1%) among M2 superior cases (p<0.001). The 90-day favorable functional outcome (mRS 0-2) and mortality (mRS 6) rates were 60.0% and 8.9% in the M2 superior, 42.9% and 32.6% in the M2 inferior, and 44.1% and 26.0% in the M1 group (n=431). Compared to M2 superior, M2 inferior favorable outcome rates were lower (p=0.094) and mortality rates were higher (p=0.003) and resembled M1 outcome rates (p=0.750 and p=0.355, respectively). ConclusionIn setting of prototypical MCA bifurcation anatomy, thrombectomy of dominant M2 inferior occlusions had outcome rates like M1 occlusions. In contrast, M2 superior occlusions had significantly lower mortality rates and a trend towards better favorable functional outcome rates.

Comparing immobilisation devices in gynaecological external beam radiotherapy: improving inter-fraction reproducibility of pelvic tilt.

The aim was to determine which immobilisation device improved inter-fraction reproducibly of pelvic tilt and required the least pre-treatment setup and planning interventions. Sixteen patients were retrospectively reviewed, eight immobilised using the BodyFIX system (BodyFIX®, Elekta, Stockholm, Sweden) and eight using the Butterfly Board (BB) (Bionix Radiation Therapy, Toledo, OH, USA). The daily pre-treatment images were reviewed to assess setup variations between each patient and groups for pelvic tilt, pubic symphysis, sacral promontory and the fifth lumbar spine (L5). Compared with the planning CT, pelvic tilt for most patients was within ±2° using the BodyFIX and ± 4° for the BB. The Butterfly Board had a slightly higher variance both for patient-to-patient (standard deviation of the systematic error) and day-to-day error (standard deviation of the random error). Variance in position between individual patients and the two stabilisation devices were minimal in the anterior-posterior (AP) and superior-inferior (SI) direction for the pubic symphysis, sacral promontory and L5 spine. Re-imaged fractions due to pelvic tilt reduced by about half when BodyFIX was used (39.1% BB, 19.4% BodyFIX). One patient treated with the BB required a re-scan for pelvic tilt. Three patients required a re-scan for body contour variations (two using BodyFIX and one with the BB). BodyFIX resulted in a more accurate inter-fraction setup and efficient treatment and is used as the standard stabilisation for gynaecological patients at our centre. It reduced the pelvic tilt variance and reduced the need for re-imaging pre-treatment by half.

Magnetic resonance image-guided adaptive radiotherapy enables safe CTV-to-PTV margin reduction in prostate cancer: a cine MRI motion study.

We aimed to establish if stereotactic body radiotherapy to the prostate can be delivered safely using reduced clinical target volume (CTV) to planning target volume (PTV) margins on the 1.5T MR-Linac (MRL) (Elekta, Stockholm, Sweden), in the absence of gating. Cine images taken in 3 orthogonal planes during the delivery of prostate SBRT with 36.25 Gray (Gy) in 5 fractions on the MRL were analysed. Using the data from 20 patients, the percentage of radiotherapy (RT) delivery time where the prostate position moved beyond 1, 2, 3, 4 and 5 mm in the left-right (LR), superior-inferior (SI), anterior-posterior (AP) and any direction was calculated. The prostate moved less than 3 mm in any direction for 90% of the monitoring period in 95% of patients. On a per-fraction basis, 93% of fractions displayed motion in all directions within 3 mm for 90% of the fraction delivery time. Recurring motion patterns were observed showing that the prostate moved with shallow drift (most common), transient excursions and persistent excursions during treatment. A 3 mm CTV-PTV margin is safe to use for the treatment of 5 fraction prostate SBRT on the MRL, without gating. In the context of gating this work suggests that treatment time will not be extensively lengthened when an appropriate gating window is applied.

Evaluating intra-fractional tumor motion in lung stereotactic radiotherapy with deep inspiration breath-hold.

To evaluate the intra-fractional tumor motion in lung stereotactic body radiotherapy (SBRT) with deep inspiration breath-hold (DIBH), and to investigate the adequacy of the current planning target volume (PTV) margins. Twenty-eight lung SBRT patients with DIBH were selected in this study. Among the lesions, twenty-three were at right or left lower lobe, two at right middle lobe, and three at right or left upper lobe. Post-treatment gated cone-beam computed tomography (CBCT) was acquired to quantify the intra-fractional tumor shift at each treatment. These obtained shifts were then used to calculate the required PTV margin, which was compared with the current applied margin of 5mm margin in anterior-posterior (AP) and right-left (RL) directions and 8mm in superior-inferior (SI) direction. The beam delivery time was prolonged with DIBH. The actual beam delivery time with DIBH (Tbeam_DIBH) was compared with the beam delivery time without DIBH (Tbeam_wo_DIBH) for the corresponding SBRT plan. A total of 113 treatments were analyzed. At six treatments (5.3%), the shifts exceeded the tolerance defined by the current PTV margin. The average shifts were 0.0±1.9mm, 0.1±1.5mm, and -0.5±3.7mm in AP, RL, and SI directions, respectively. The required PTV margins were determined to be 4.5, 3.9, and 7.4mm in AP, RL, and SI directions, respectively. The average Tbeam_wo_DIBH and Tbeam_DIBH were 2.4±0.4 min and 3.6±1.5 min, respectively. The average treatment slot for lung SBRT with DIBH was 25.3±7.9 min. Intra-fractional tumor motion is the predominant source of treatment uncertainties in CBCT-guided lung SBRT with DIBH. The required PTV margin should be determined based on data specific to each institute, considering different techniques and populations. Our data indicate that our current applied PTV margin is adequate, and it is possible to reduce further in the RL direction. The time increase of Tbeam_DIBH, relative to the treatment slot, is not clinically significant.

Stochastic time series analysis of atrial fibrillatory electrograms in paroxysmal atrial fibrillation

Abstract Background/Introduction Regional dominant frequency and instantaneous frequency modulation of short fractionated atrial electrograms have been associated with ablation targets and the prognosis of atrial fibrillation (AF). However, inconsistent and not fully comprehensible results have been reported. Purpose To construct a simple computational algorithm for the analysis of continuous fibrillatory atrial electrograms and evaluate it in clinical practice, among patients with paroxysmal AF. Methods Before the first cryo-balloon ablation, 3-minute continuous local electrogram recordings during pace-induced AF were obtained by the circumferential catheter from the left atrial appendage (LAA) and each pulmonary vein: left superior (LSPV), left inferior (LIPV), right superior (RSPV) and right inferior (RIPV). Following time- and frequency-domain analysis, non-linear detrended fluctuation analysis (DFA α) with analysis for short-term (DFA α1) and long-term fluctuations (DFA α2) was performed. The signals were detrended by subtracting time series polynomial fit and badpass filtered in the MATLAB environment (cut-off voltage 0.1 mV to avoid scar and artifacts). Results Fifteen patients were studied. Among different atrial areas, higher mean peak rate (pr) along with lower standard deviation of between peaks intervals (sdpp) and root square of peak-to-peak differences (rmppd) were observed in the LAA and left veins (Fig. 1). In patients with longer AF history (&amp;gt; 2 yrs), lower α, α1 and α2 exponents of DFA were observed (Fig. 2). Conclusions This algorithm depicted dissimilar impact on atrial electrical activity between different atrial areas. Patients with longer AF history had less self-similarity in local LAA electrograms. This might indicate possible ablation targets and reveal patients with greater AF burden and worse arrhythmic prognosis.Leftheriotis - Figure 1Leftheriotis - Figure 2

Characteristics of optic disc hemorrhage and optic nerve changes following acute primary angle closure

IntroductionAcute primary angle closure (APAC) is an emergency ophthalmic presentation and a major cause of irreversible blindness in China. However, only a few studies have focused on the characteristics of optic disc hemorrhage (ODH) during an APAC attack, including its shape, depth, location, scope, and duration after intraocular pressure (IOP) control, along with changes in the optic nerve. This study aimed to analyze the characteristics of ODH and optic nerve changes in patients during their first APAC episode.MethodsThis retrospective study involved 32 eyes from 32 patients with APAC who received sequential treatment and analyzed the following parameters: the highest IOP and its duration, ODH, retinal nerve fiber layer thickness (RNFLT), and mean deviation (MD). We compared parameters obtained from the affected eye (ODH group) and contralateral unaffected eye (control group), as well as intragroup comparisons.ResultsThe mean IOP in the ODH group was 64.28 ± 10.36 mmHg, with a duration of 4.44 ± 2.35 days. Flame and splinter shapes accounted for 84.38% of the ODH. The mean ODH duration was 4.81 ± 3.25 weeks. ODH during APAC was isolated to one sector in 59.38% of cases, mostly occurring in the temporal superior and temporal inferior (each accounting for 21.88% of the cases). There was a positive correlation between the extent of hemorrhage and the highest IOP duration (p &amp;lt; 0.001). RNFLT was significantly thickened within 72 h post-IOP control but was thinned by 2 weeks. By 6 months, the thinning stabilized, and there was no difference noted between the ODH and control groups at 12 months. MD partly improved at 6 months post-IOP control, and ODH scope significantly affected the MD (p &amp;lt; 0.001). The duration of high IOP was positively correlated to the ODH scope and MD damage.DiscussionTimely and effective IOP management is essential for recovering visual function following an APAC attack.

The Tribe Affiliation of the Romans in the Lower Danube

The article deals with the perception of the tribe Papiria in the nomenclature of the Roman civics in two Trajanic colonies in Moesia Superior and Moesia Inferior—col(onia) Ulp(ia) Tra(iana) Rat(iariensium) and col(onia) Ulp(ia) Oescensium respectively. Although located close geographically and with a few common traits of their historical development, some discrepancies appeared in the topic which are discussed. The inscriptions provide, although scanty, some information on the tribe affiliation of the civic and religious colonial elite, augustales coloniae as well as the tribe affiliation as a part of a certain ornamenta. All this allows to establish the Roman tribe as an important social marker and for prestige in the Roman civic community, and can therefore serve in the Roman provinces as a sign of the progress of urbanization and Romanization. Certainly, the observations made are preliminary due to the scanty evidence available so far for various reasons.

Feasibility of patient-specific quality assurance (PSQA) for real-time robotic stereotactic body radiotherapy (SBRT) based on tumor motion traces.

To design a patient specific quality assurance (PSQA) process for the CyberKnife Synchrony system and quantify its dosimetric accuracy using a motion platform driven by patient tumor traces with rotation. The CyberKnife Synchrony system was evaluated using a motion platform (MODUSQA) and a SRS MapCHECK phantom. The platform was programed to move in the superior-inferior (SI) direction based on tumor traces. The detector array housed by the StereoPhan was placed on the platform. Extra rotational angles in pitch (head down, 4.0°±0.15° or 1.2°±0.1°) were added to the moving phantom to examine robot capability of angle correction during delivery. A total of 15 Synchrony patients were performed SBRT PSQA on the moving phantom. All the results were benchmarked by the PSQA results based on static phantom. For smaller pitch angles, the mean gamma passing rates were 99.75%±0.87%, 98.63%±2.05%, and 93.11%±5.52%, for 3%/1mm, 2%/1mm, and 1%/1mm, respectively. Large discrepancy in the passing rates was observed for different pitch angles due to limited angle correction by the robot. For larger pitch angles, the corresponding mean passing rates were dropped to 93.00%±10.91%, 88.05%±14.93%, and 80.38%±17.40%. When comparing with the static phantom, no significant statistic difference was observed for smaller pitch angles (p=0.1 for 3%/1mm), whereas a larger statistic difference was observed for larger pitch angles (p<0.02 for all criteria). All the gamma passing rates were improved, if applying shift and rotation correction. The significance of this work is that it is the first study to benchmark PSQA for the CyberKnife Synchrony system using realistically moving phantoms with rotation. With reasonable delivery time, we found it may be feasible to perform PSQA for Synchrony patients with a realistic breathing pattern.

Creep behavior and fracture mechanism of an additively manufactured 316L stainless steel with extraordinary creep resistance

The creep behaviors of laser powder bed fusion (LPBF) additively manufactured (AM) 316L stainless steel (SS) and its recrystallized (Re) counterpart were investigated via uniaxial constant-load creep tests at 600 °C with nominal stress levels ranging from 235 to 360 MPa. Anisotropic creep behavior was observed in AM 316L SS, with superior creep resistance but inferior creep ductility in the horizontal sample (loaded perpendicular to the build direction (BD)) compared to the vertical sample (loaded parallel to the BD). This superior creep resistance was likely resulted from shorter dislocation slip distance and the inferior creep ductility was due to faster propagation of cracks along the columnar grain boundaries. Compared with both the Re counterpart and conventional 316L SS, AM 316L SS in this study exhibited an extraordinary creep resistance at various stress levels, with the minimum creep rate being two to three orders of magnitude lower and much longer creep life. This exceptional creep resistance of AM 316L SS was attributed to the presence of dislocation cells that impeded the deformation-induced dislocations. This led to a remarkably low rate of creep deformation and delayed the creep crack initiation, ultimately resulting in a long creep life. The gradual development of the precipitate films enriched with Mo, Si and Cr along high-angle grain boundaries, following prolonged exposure to high temperatures, was found to restrict the creep ductility in AM 316L under low stress conditions. Nevertheless, the study demonstrates that the stable dislocation cells are beneficial in enhancing the high-temperature creep resistance of AM 316L SS.

Information fusion-based maintenance strategies selection for coastal concrete bridges using recycled fishing nets

Repurposing recycled materials for coastal concrete bridge maintenance addresses both engineering requirements and marine ecosystem preservation. This study explored the application of recycled nylon (RN) and polyethylene (PE) from discarded fishing nets in coastal concrete beam maintenance. Specifically, these fibers were incorporated into the polymer cement mortar (PCM) to produce two repair materials. Then, thirteen unrepaired or preventive/post-repaired concrete beams were exposed to the tidal zone for one or two years, followed by beam bending tests and the establishment of the corresponding parametric Finite element modeling (FEM). As an alternative to traditional heavy-parameter models, a novel lightweight crack segmentation model (LiteSqueezeSeg) was proposed for quantitatively analyzing beam surface crack properties. Lastly, experimental, simulated, and quantitative crack information were fused to comprehensively assess the beam performance. Results showed that both PCM-RN and PCM-PE effectively inhibit chloride ion penetration. The proposed LiteSqueezeSeg model (95.66% accuracy) achieved nearly identical performance to Deeplab v3 + but only with about 1/6 parameters. Fused results revealed that PCM-PE repaired beams exhibited superior mechanical performance but inferior ductility compared to PCM-RN. Moreover, both PCM-PE and PCM-RN repaired beams demonstrated that preventive repairs achieved more balanced performance than post repairs. Consequently, utilizing PCM-RN for preventive repair emerged as an optimal candidate. This study significantly contributes to the utilization of waste fishing nets in coastal concrete structure maintenance.

Study of degenerative (non-lytic) spondylolisthesis grade 1 and 2 in axial MRI images

Background: The traditional imaging assessment of lumbar spondylolisthesis is in sagittal images noting movement of upper body over the lower body. It omits change at the facet. Methods: The present observational, study included 35 patients with degenerative lumbar spondylolisthesis(non-lytic). Radiological analysis of all MRI images was done by 4 independent spinal surgeons and 2 radiologists. The study focused on the axial MRI images and changed relation between the superior articular process and inferior articular process and relation between inferior articular process and canal with thecal sac (traversing root). Results: Majority of DS had sagittal oriented facets (71.43%). In 7 cases at the L3/4 and in 19 cases at L4/5 level both facet joints had sagittal orientation with forward (ventral) movement of IAP. The IAP was found to be encroaching or in close proximity of traversing root. In 1 patient at L3/4 and 6 patients at L4/5 joint was sagittal unilaterally, may be causing compression of the neural elements unilaterally, while on coronal side the IAP and SAP had a normal alignment and not causing neural encroachment Conclusions: We need to concentrate on relation of IAP vs SAP at facet as seen in axial images of facet.

Interpreting compression resistance and resilience of spacer fabrics with morphological and mechanical changes of different polymeric spacer monofilaments

Customization of spacer fabrics to have the desired compression resistance and resilience is critical to promote their technical applications. The compression properties are mainly determined by the mechanical features of monofilaments used as spacer yarns. This study investigates the compression properties of spacer fabrics knitted with different polymeric monofilaments by analyzing their compression stress at 40% strain, residual strain, and energy absorption from cyclic compression tests. The monofilaments in the fabrics before and after cyclic compression were unraveled to test their tensile properties and morphologies for interpreting their different fabric compression properties. It was found that knitting monofilaments substantially alters their macroscopic and/or microscopic structures, thereby affecting the mechanical behavior of spacer monofilaments, and having different fabric structures and compression properties. Knitting polyethylene terephthalate monofilament damages the mesophase and induces a two-thirds decline in Young's modulus, while knitting polyamide 6 and polybutylene terephthalate monofilaments largely alters the macrostructures but maintains their good resilience. Spacer fabrics knitted with stiffer polyethylene terephthalate monofilaments have superior compression resistance but inferior compression resilience, while those knitted with softer and more resilient polyamide 6 and polybutylene terephthalate monofilaments have better compression resilience. Polyethylene monofilament is not suitable for spacer fabrics because of its low Young's modulus and poor tensile resilience. Polyethylene terephthalate spacer fabrics have the best compression resistance–resilience balance in terms of compression stress at 40% strain and residual strain in the fourth cycle required by the standard EN ISO 3386-1, while polyamide 6 and polybutylene terephthalate monofilaments are more suitable for long-term service due to their high compression resistance and resilience.

CHEMICAL OCULAR INJURY BY POTASSIUM PERMANGANATE

Abstract Introduction &amp; Objectives : Chemical ocular injury is an emergency case and commonly occured among children. Alkaline chemical ocular injury is more destructive especially due to saponification. One of the rare chemical ocular injury is alkaline trauma by Potassium Permanganate (KMNO4) Methods : A case of a three-year-old boy patient brought by his mother in emergency department at Cicendo Eye Hospital with severe pain, redness, and swelling of the left eye. Ten hours earlier, the patient was playing and accidentally exposed to KMNO4. Visual acuity of the right eye was 6/6 and the left eye was difficult to examine. Ophthalmological examination revealed superior and inferior palpebra are swelling, KMNO4 adhered tightly on conjunctival tarsal superior, inferior, and conjunctival bulbi inferior until fornix and temporal area. Cornea was hazed and iris shadow test positive so he was diagnosed with Chemical Trauma Ropper Hall grade II OS. Treatment begins with irrigation 2 litres of normal saline until pH 7 along with debridement of KMNO4 from conjunctival tarsal superior inferior and bulbi. The patient underwent installation of transplanted amniotic membrane and debridement under anasthesia Results : Management in the initial phase is irrigation. The definitive therapy requires surgery to speed up the healing process. Complications that often occur are corneal limbal cell deficiency, dry eye, symblepharon formation, secondary glaucoma, and complicated cataracts Conclusion : Alkali chemical injury is hazardous and can lead to severe vision threatening complications because of saponification. Prompt and aggressive management is required in such cases to give them the best chance of a more favourable outcome

Comparison of Smartphone and internet addiction and Optical Coherence Tomography findings among University students

IntroductionInternet and smartphone use that reaches the level of addiction often leads to deterioration in the quality of life and functionality of individuals.ObjectivesIn our study, we aimed to investigate possible differences in retinal nerve fiber layer (RNFL) thickness and central macular thickness obtained by optical coherence tomography in internet and smartphone addiction.MethodsA total of 212 volunteer university students participated in our study. All participants were administered the Sociodemographic Information Form, Chen Internet Addiction Scale, Smartphone Addiction Scale-Short Form. Participants who completed the scales underwent routine eye examinations by experienced physicians in the ophthalmology outpatient clinic. Retinal nerve fiber layer (RNFL) thickness and central macular thickness were measured by optical coherence tomography (OCT).ResultsIn our study, internet addiction rate was 17% and smartphone addiction rate was 38.2%. RNFL thickness was found to be statistically significantly increased in the temporal superior and temporal inferior quadrants in those with internet addiction compared to healthy subjects (p&lt;0.05). In smartphone addiction, RNFL thickness was found to be statistically significantly increased in the temporal inferior quadrant compared to healthy subjects (p&lt;0.05). In the analyses comparing OCT measurements according to sex, it was found that nasal inferior (p&lt;0.01) and global (p&lt;0.05) quadrants in women and central macular thickness (p&lt;0.01) in men were statistically significantly increased.The correlation analyses in our study revealed statistically significant positive correlations between internet addiction scale scores (p&lt;0.01) and smartphone addiction scale scores (p&lt;0.01), RNFL temporal superior quadrant thickness (p&lt;0.01); smartphone addiction scale scores and RNFL temporal superior quadrant thickness (p&lt;0.05).ConclusionsInternet and smartphone addiction are seen considerable rates among university students. In OCT measurements, RNFL thickness was found to be increased in various quadrants in patients with addiction. In addition, RNFL thickness was found to be increased in all quadrants in female gender and central macular thickness was found to be increased in male gender. Correlation analysis revealed that internet addiction scale scores, smartphone addiction scale scores, and RNFL temporal superior quadrant thickness were positively correlated. In addition, there was a positive correlation between smartphone addiction scale scores, and RNFL temporal superior quadrant thicknessDisclosure of InterestNone Declared

Changes in pulmonary vein size and narrowing depend on the cardiac cycle before and after pulmonary vein isolation.

Accurate measurement of the pulmonary vein dimension (PVD) is important for determining stenosis and efficacy following pulmonary vein isolation (PVI). Little is known about the quantitative evaluation of the impact of the cardiac cycle on pulmonary vein (PV) morphology before and after PVI. This study aims to investigate variations in the ostial size of the PV during the cardiac cycle before and after PVI and the effect of the cardiac cycle on PV stenosis and reduction rate using cardiac computed tomography (CT). Sixty-eight patients with atrial fibrillation who underwent cardiac CT before and after PVI at our institution between 23 January 2021 and 5 February 2022 were retrospectively analyzed. The maximum and minimum PVD were measured at each segment before and after the PV. Each PV was evaluated according to the PVD reduction rate (ΔPVD), calculated as follows: (1 - post-PVD/pre-PVD) × 100 (%). The average dimension of all PVs at the end-diastolic frame was significantly reduced compared to that at the end-systolic frame before PVI. The average dimensions of the right superior and right inferior PV at the end-diastolic frame were significantly reduced compared with those at the end-systolic frame following PVI. The average reduction rate of dimension-classified stenosis of PVs, except for the left inferior PV at the end-diastolic frame, was significantly reduced compared with that at the end-systolic frame. The cardiac cycle affects PVD assessment, including PV stenosis, after PVI. PVD measurement is recommended to be unified to the end-systolic frame of the cardiac cycle to avoid underestimating PV stenosis before and after PVI, ensuring appropriate management and follow-up.

Sensitivity of Phonation Onset Pressure to Vocal Fold Stiffness Distribution.

Phonation onset is characterized by the unstable growth of vocal fold (VF) vibrations that ultimately results in self-sustained oscillation and the production of modal voice. Motivated by histological studies, much research has focused on the role of the layered structure of the vocal folds in influencing phonation onset, wherein the outer "cover" layer is relatively soft and the inner "body" layer is relatively stiff. Recent research, however, suggests that the body-cover (BC) structure over-simplifies actual stiffness distributions by neglecting important spatial variations, such as inferior-superior (IS) and anterior-posterior gradients and smooth transitions in stiffness from one histological layer to another. Herein, we explore sensitivity of phonation onset to stiffness gradients and smoothness. By assuming no a priori stiffness distribution and considering a second-order Taylor series sensitivity analysis of phonation onset pressure with respect to stiffness, we find two general smooth stiffness distributions most strongly influence onset pressure: a smooth stiffness containing aspects of BC differences and IS gradients in the cover, which plays a role in minimizing onset pressure, and uniform increases in stiffness, which raise onset pressure and frequency. While the smooth stiffness change contains aspects qualitatively similar to layered BC distributions used in computational studies, smooth transitions in stiffness result in higher sensitivity of onset pressure than discrete layering. These two general stiffness distributions also provide a simple, low-dimensional, interpretation of how complex variations in VF stiffness affect onset pressure, enabling refined exploration of the effects of stiffness distributions on phonation onset.

Deep learning-based target decomposition for markerless lung tumor tracking in radiotherapy.

In radiotherapy, real-time tumor tracking can verify tumor position during beam delivery, guide the radiation beam to target the tumor, and reduce the chance of a geometric miss. Markerless kV x-ray image-based tumor tracking is challenging due to the low tumor visibility caused by tumor-obscuring structures. Developing a new method to enhance tumor visibility for real-time tumor tracking is essential. To introduce a novel method for markerless kV image-based tracking of lung tumors via deep learning-based target decomposition. We utilized a conditional Generative Adversarial Network (cGAN), known as Pix2Pix, to build a patient-specific model and generate the synthetic decomposed target image (sDTI) to enhance tumor visibility on the real-time kV projection images acquired by the onboard kV imager equipped on modern linear accelerators. We used 4DCT simulation images to generate the digitally reconstructed radiograph (DRR) and DTI image pairs for model training. We augmented the training dataset by randomly shifting the 4DCT in the superior-inferior, anterior-posterior, and left-right directions during the DRR and DTI generation process. We performed real-time 2D tumor tracking via template matching between the DTI generated from the CT simulation and the sDTI generated from the real-time kV projection images. We validated the proposed method using nine patients' datasets with implanted beacons near the tumor. The sDTI can effectively improve the image contrast around the lung tumors on the kV projection images for the nine patients. With the beacon motion as ground truth, the tracking errors were on average 0.8±0.7mm in the superior-inferior (SI) direction and 0.9±0.8mm in the in-plane left-right (IPLR) direction. The percentage of successful tracking, defined as a tracking error less than 2mm in the SI direction, is 92.2% on the 4312 tested images. The patient-specific model took approximately 12h to train. During testing, it took approximately 35ms to generate one sDTI, and 13ms to perform the tumor tracking using template matching. Our method offers the potential solution for nearly real-time markerless lung tumor tracking. It achieved a high level of accuracy and an impressive tracking rate. Further development of 3D lung tumor tracking is warranted.

The Contribution of 18F FDG PET-CT for the Investigation of Fever of Unknown Origin and Inflammation of Unknown Origin

BackgroundFever of unknown origin and inflammation of unknown origin are highly challenging diagnostic conditions. The current practice for evaluating patients is to conduct a positron emission tomography-computed tomography (PET-CT) scan as either a first- or a second-line modality. We aimed to assess the contributory effect of PET-CT to the diagnosis and compare it with the contributory effect of CT alone. MethodsWe performed a systematic review and meta-analysis. We included all cohorts that examined the contribution of PET-CT to the investigation of classical fever of unknown origin and inflammation of unknown origin. The primary outcome was the contribution of PET-CT to the final diagnosis. Secondary outcomes were sensitivity and specificity of PET-CT and CT scans, and contribution of a CT scan. We pooled the results of all studies and calculated the pooled contributory effect of PET-CT. ResultThirty-six studies (3516 patients) were included in the systematic review. The pooled contribution of PET-CT was 75.4%. The compiled sensitivity and specificity values for all studies were 85.9% and 59.5%, respectively. Five studies (405 patients) compared between the PET-CT component and the total body CT component. The pooled contribution of a CT scan was 68%. The summed sensitivity and specificity values of a CT scan for all studies were 63.1% and 84.4%, respectively. ConclusionsPET-CT has a contributory effect of 75% for the diagnosis of fever of unknown origin and inflammation of unknown origin. PET-CT had superior sensitivity and inferior specificity vs the CT scan.