Tear Area Research Articles

Determinants of Patient-Rated Benefit 6 Months Post Arthroscopic Rotator Cuff Repair: An Analysis of 2010 Patients.

From the surgeon's perspective, a successful rotator cuff is one that remains intact. However, it is undetermined which factors contribute to an improved shoulder from the patient's perspective. The aim of this study was to determine the variables that predicted greater patient-rated benefit from presurgery to 6 months postarthroscopic rotator cuff repair. Multiple linear regression analysis was conducted on prospectively collected data of 2010 consecutive patients who underwent arthroscopic rotator cuff repair by a single surgeon to determine the predictors of greater patient-rated benefit. Patient-rated shoulder ranking was graded on a five-point Likert scale in response to "How is your shoulder overall?" preoperatively and at 6 months postoperatively. The patient-rated benefit was the difference in rankings between these time points. Six months following rotator cuff repair, a self-reported benefit was observed in 84% of patients. Patients who rated their shoulder as poor preoperatively reported the greatest benefit (t = 22, P < 0.001). Other preoperative determinants of greater patient-rated benefit were lower patient-rated shoulder stiffness (t = 5, P < 0.001), an injury that was not related to work (t = 4, P < 0.001), stronger internal rotation strength (t = 4, P < 0.002), a more strenuous line of work preinjury (t = 3, P = 0.007), female sex (t = 2, P = 0.019), having a larger tear area (t = 2, P = 0.020), and weaker abduction strength (t = 2, P = 0.046). Patients who were most likely to perceive a benefit from rotator cuff repair at 6 months postoperation were those who preoperatively rated their shoulder poorly, had a less stiff shoulder, an injury that was not related to work, stronger internal rotation, more strenuous line of work preinjury, were female, had larger tear area, and weaker abduction strength.

Comparative analysis of functional outcomes in arthroscopic repair for traumatic and non-traumatic rotator cuff injuries

BackgroundThe impact of the etiology of rotator cuff injury (RCI) on outcomes after rotator cuff repair remains unclear. This study aimed to evaluate the postoperative outcomes of patients with RCIs of different etiologies and identify the risk factors affecting prognosis.MethodsThis study included 73 patients with RCI who underwent arthroscopic rotator cuff repair. The patients were categorized into either a traumatic group or a non-traumatic group based on their history of trauma. Preoperative and postoperative assessments included shoulder range of motion, muscle strength, and physical examination findings specific to the shoulder for both groups. Clinical differences between arthroscopic repair of traumatic and non-traumatic RCIs were evaluated using univariate analysis. Logistic regression analysis determined independent risk factors for rotator cuff repair prognosis.ResultsAmong the 73 patients, 31 were in the traumatic group and 42 in the non-traumatic group, with a minimum postoperative follow-up of 12 months and a mean follow-up of 13.8 months. The duration of the disease was significantly longer in the non-traumatic group compared with the traumatic group (P < 0.001). The mean tear area was more significant in the traumatic group than in the non-traumatic group (P = 0.003), and the preoperative pain level and functional scores were better in the non-traumatic group compared with the traumatic group. Postoperatively, there were no differences between the two groups regarding scores, joint mobility, strength, and complications. At 12 months postoperatively, multivariate regression analysis indicated that full-layer tear (OR = 5.106, 95% CI: 1.137–22.927, P = 0.033), fat infiltration (OR = 6.020, 95% CI: 1.113–32.554, P = 0.037), and tear area (OR = 6.038, 95% CI: 2.122–17.177, P < 0.001) significantly affected the University of California at Los Angeles (UCLA) score.ConclusionCompared with non-traumatic RCI, traumatic RCI presents with more pronounced pain and impaired joint function preoperatively yet demonstrates comparable postoperative clinical outcomes. Full-layer tears, fat infiltration, and large tear areas are unfavorable factors affecting rotator cuff repair, and postoperative rehabilitation management of these patients should be emphasized.

Localized Evaporative Cooling Explains Observed Ocular Surface-Temperature Patterns.

We determined interblink corneal surface-temperature decline and tear-film evaporation rates of localized tear breakup cold regions (LCRs) and localized tear unbroken warm regions (LWRs) of the corneal surface, as well as that of the overall average corneal surface. Each subject underwent 4 inter-day visits where the interblink corneal surface-temperature history of the right eye was measured using a FLIR A655sc infrared thermographer. Corneal surface temperature history was analyzed to determine the overall, LCR, and LWR temperature-decline rates. Evaporation rates of LCR and LWR regions were determined from the measured LCR and LWR temperature data using the physical model of Dursch et al. Twenty subjects completed the study. Mean (SD) difference of LCR temperature-decline rate was -0.08 (0.07)°C/s faster than LWR (P < 0.0001). Similarly, evaporation rates of LCR and LWR were statistically different (P < 0.0001). At ambient temperature, mean LCR and LWR evaporation rates were 76% and 27% of pure water evaporation flux, respectively. There was no statistically significant difference between the inter-day measured temperature-decline rates and the interblink starting temperature. Significant differences in corneal temperature-decline rate and evaporation rate between LCR and LWR were quantified using infrared thermography. In agreement with literature, LCRs and LWRs correlate directly with fluorescein break-up areas and unbroken tear areas, respectively. Because lipid-evaporation protection is diminished in breakup areas, higher local evaporation rates and faster local cooling rates occur in LCRs relative to LWRs. Our results confirm this phenomenon clinically for the first time.

A rare case report: Brucellosis as an extreme cause of shoulder subluxation and rotator cuff tendinopathy

Rationale: Shoulder subluxation and rotator cuff tendinopathy is commonly associated with degeneration or trauma, and brucellosis has been reported to be correlated with shoulder subacromial bursitis, arthritis. However, brucellosis as a cause of shoulder subluxation and rotator cuff tendinopathy has never been reported in the English medical literature. Patient concerns: A 46-year-old man complained of left shoulder weakness and limited movement ongoing for 1 month. He was primarily diagnosed with shoulder subluxation and rotator cuff tear based on magnetic resonance imaging, and was advised to undergo arthroscopic rotator cuff surgical repair. Diagnoses: Although rotator cuff tear was diagnosed in another hospital, some doubts remained. First, a tendon profile with a relative high signal in T2-weighted magnetic resonance images in the supraspinatus tear area still existed. The findings were clearly different from the usual full-thickness rotator cuff tear, and no tendon profile could be found in the tear area. Second, degenerative rotator cuff tear mainly occurs in the aged population and this patient was relatively young, without a history of trauma. His left shoulder was painless but the weakness and the limited movement were extreme and all of these factors did not support the diagnosis of rotator cuff tear. Some infectious disease was suspected to be the cause and relevant laboratory tests were conducted. This patient was eventually diagnosed as having brucellosis-associated shoulder subluxation and rotator cuff tendinopathy based on positive serum standard tube agglutination test and buffer plate agglutination test for brucellosis. Interventions: Oral drug therapy with rifampicin and doxycycline was used for 8 weeks. Outcomes: A complete response with normal shoulder strength and movement was achieved at 8 weeks. At the one-year follow-up no signs of recurrence were detected. Lessons: Brucellosis-associated shoulder subluxation and rotator cuff tendinopathy may be misdiagnosed as a rotator cuff tear in magnetic resonance imaging and be further managed with indeterminate arthroscopic repair. A comprehensive understanding of the patient’s previous medical history, imaging and laboratory data and a careful physical examination are of great clinic value for the accurate diagnosis of the condition and the subsequent prognosis of the patient.

MRI findings correlate with difficult dissection during proximal hamstring repair and with postoperative sciatica.

This study examines the correlation between MRI findings and difficult dissection during proximal primary hamstring repair and postoperative sciatica. A total of 32 cases of surgically repaired hamstring tendon tears that underwent preoperative and postoperative MRI were divided into sciatica (n = 12) and control (n = 20) groups based on the presence or absence of postoperative sciatica. Cases were scored by two blinded musculoskeletal radiologists for imaging features associated with difficult surgical dissection and the development of subsequent sciatica. Intra- and interrater agreements, as well as correlation of MRI findings with symptoms (odds ratio, OR), were calculated. On preoperative MRI, diffuse hamstring muscle edema pattern suggestive of active denervation (OR 9.4-13.6), and greater sciatic perineural scar circumference (OR 1.9-2) and length (OR 1.2-1.3) were significantly correlated with both difficult dissection and postoperative sciatica. Preoperatively, a greater number of tendons torn (OR 3.3), greater tear cross-sectional area (CSA, OR 1.03), and increased nerve T2-weighted signal (OR 3.2) and greater perineural scar thickness (OR 1.7) were also associated with difficult dissection, but not postoperative sciatica. On postoperative MRI, hamstring denervation, sciatic nerve tethering to the hamstring tendon, and development of perineural scar and greater perineural scar extent were all significantly correlated with postoperative sciatica. Preoperative hamstring MRI demonstrates findings predictive of difficult sciatic nerve dissection; careful MRI evaluation of the nerve and for the presence and extent of perineural scar is important for preoperative planning. Preoperative and postoperative MRI both depict findings that correlate with postoperative sciatica.

Tomo-seq identifies NINJ1 as a potential target for anti-inflammatory strategy in thoracic aortic dissection

BackgroundThoracic aortic dissection (TAD) is a life-threatening disease caused by an intimal tear in the aorta. The histological characteristics differ significantly between the tear area (TA) and the distant area. Previous studies have emphasized that certain specific genes tend to cluster at the TA. Obtaining a thorough understanding of the precise molecular signatures near the TA will assist in discovering therapeutic strategies for TAD.MethodsWe performed a paired comparison of the pathological patterns in the TA with that in the remote area (RA). We used Tomo-seq, genome-wide transcriptional profiling with spatial resolution, to obtain gene expression signatures spanning from the TA to the RA. Samples from multiple sporadic TAD patients and animal models were used to validate our findings.ResultsPathological examination revealed that the TA of TAD exhibited more pronounced intimal hyperplasia, media degeneration, and inflammatory infiltration compared to the RA. The TA also had more apoptotic cells and CD31+α-SMA+ cells. Tomo-seq revealed four distinct gene expression patterns from the TA to the RA, which were inflammation, collagen catabolism, extracellular matrix remodeling, and cell stress, respectively. The spatial distribution of genes allowed us to identify genes that were potentially relevant with TAD. NINJ1 encoded the protein-mediated cytoplasmic membrane rupture, regulated tissue remodeling, showed high expression levels in the tear area, and co-expressed within the inflammatory pattern. The use of short hairpin RNA to reduce NINJ1 expression in the beta-aminopropionitrile-induced TAD model led to a significant decrease in TAD formation. Additionally, it resulted in reduced infiltration of inflammatory cells and a decrease in the number of CD31+α-SMA+ cells. The NINJ1-neutralizing antibody also demonstrated comparable therapeutic effects and can effectively impede the formation of TAD.ConclusionsOur study showed that Tomo-seq had the advantage of obtaining spatial expression information of TAD across the TA and the RA. We pointed out that NINJ1 may be involved in inflammation and tissue remodeling, which played an important role in the formation of TAD. NINJ1 may serve as a potential therapeutic target for TAD.

Анализ архитектурно-планировочных решений поликлиник как инструмент управления при внедрении бережливого производства.

In the clinics of the Moscow region, within the framework of the project «A new model of a medical organization providing primary medical care», there is difficulty in achieving the target indicators of the project criteria. The analysis of the architectural and planning characteristics of polyclinics that affect the achievement of the criteria of this project was carried out. Purpose: analysis and evaluation of the architectural and planning capabilities of polyclinics in the Moscow region for the successful implementation of lean production technologies. Materials and methods: 224 polyclinics of the Moscow region were included in the project, statistical reporting forms were evaluated: Analysis of data from the federal register of medical organizations, forms of federal statistical observation No. 30, No. 47. shortage of polyclinic capacity), depreciation of polyclinic buildings. Research methods – analytical, observation, expert, mathematical, statistical. Results. In the clinics of the Moscow region, there is an imbalance between the attached population and the design capacity of the clinics. Also, a pronounced variability in the area of polyclinics in the Moscow region was revealed, 34% of polyclinics have a shortage of space. The physical deterioration of buildings leads to a limitation in their operation. Conclusions. Polyclinics of the Moscow region differ in variability in terms of capacity, shortage or redundancy of the area of polyclinics, wear and tear of the building, architectural and planning features of polyclinics. These criteria must be taken into account when choosing projects for the most effective achievement of results.

Head-Tilt Perfluorocarbon-Air Exchange Technique With Heads-Up Surgery for Giant Retinal Tear-Associated Retinal Detachments to Prevent Retinal Slippage Without Using Silicone Oil.

To report the efficacy of the perfluorocarbon liquid-air exchange with a head tilt toward the area of the giant retinal tear (GRT) using the heads-up surgery system to prevent retinal slippage during vitrectomy for GRT-associated retinal detachments. Eyes with GRT-associated retinal detachments underwent vitrectomy using the heads-up surgery system and perfluorocarbon liquid-air exchange with a head tilt 45° toward the GRT to put the area of the tear in the most dependent position to drain fluid. This technique was evaluated to prevent retinal slippage. Five consecutive cases were evaluated. The mean GRT size was 174° (range, 90-240°) and the GRT was located temporally in two eyes, nasally in two eyes, and superiorly in one eye. The tamponade types were air (1 eye), sulfur hexafluoride (3 eyes), and perfluoropropane (1 eye). Our technique was feasible and the slippage did not occur in any eyes. Although the microscope needed to be tilted for optimal fundus visualization, heads-up surgery allowed surgeons to maintain ergonomic postures. Retinal reattachment was achieved with a single surgery in all eyes. The head-tilt perfluorocarbon liquid-air exchange with heads-up surgery is useful in preventing retinal slippage in eyes with GRT.

Tracking the evolution of hot tears in aluminium alloys using high-speed X-ray imaging

Hot tears are detrimental defects forming during the final stage of solidification when the remaining liquid loses the capacity to compensate for liquid to solid volume shrinkage. Although a mature semi-quantitative description of hot tearing has been developed, little is known about the dynamic evolution of hot tears as experimental studies have been conducted mostly post-solidification or in semi-static in-situ conditions. Here, we present a methodology to investigate the evolution of hot tears with high spatial and temporal resolution using synchrotron-based X-ray radiography. We develop a novel hot tear detection and tracking algorithm for quantification of hot tear density, area fraction and merging from the analysis of radiographic sequences of the solidification of thin metal samples. The methodology is demonstrated for an Al-5wt%Cu alloy and examples of the results and new insights that can be achieved are described.

The pathoanatomy of atraumatic partial distal biceps tears: a cadaveric study

Partial distal biceps tears can occur in the short and/or long heads, leading to forearm pain and weakness. Yet, the pathoanatomy of atraumatic and traumatic partial tears are not understood. The goals of this study are to determine the distal biceps partial tear frequency and tear pattern in a cohort of cadaveric specimens. Fifty three fresh frozen cadavers (average age 70.4±13.8 years, range 32-94) underwent elbow endoscopy to screen for partial tears. The partial tendon tear pattern was classified into either attritional (atraumatic), detachment on the tendon's lateral side, or avulsion (traumatic) rupture of the tendon fibers from bone on both the lateral and medial sides. The specimens were dissected and laser scanned to make 3D models. The tear location, shape, and area were calculated using gross dissection and the 3D models. Atraumatic partial distal biceps tears were identified in 40% of the specimens, 72% involved both the long and short heads, 14% long head, and 14% short head. In all tears, the tendon fibers were only detached from the lateral side. The greatest tear width occurred near the short and long head junction. Atraumatic partial distal biceps tears are common. The tear originates on the lateral side of the tendon at the short and long head junction. All the tear patterns are attritional and no specimen had surgical treatment. This finding supports the current treatment recommendation of an initial period of nonoperative care for symptomatic atraumatic partial distal biceps tears.

Horseshoe retinal tear: factors that determine the risk of developing rhegmatogenous retinal detachment

This study aimed to determine the main risk factors for RRD development based on the analysis of the condition of vitreoretinal interface in the area of horseshoe tears, both isolated and those that resulted in retinal detachment. A total of 88 patients with horseshoe retinal tears (43 patients with RRD due to the horseshoe tear and 45 with isolated horseshoe tears) were included in the study. All patients underwent wide-field multispectral laser scanning and optical coherence tomography to determine the shape of the horseshoe tear and the extent of vitreoretinal adhesion (VRA). Cluster analysis was used to differentiate horseshoe tears by shape. Spearman's correlation analysis was used to identify the relationship between the shape of the horseshoe tear and localization of VRA. Spearman's correlation analysis revealed a strong negative correlation between the length-to-width ratio of the horseshoe tear and the extent of VRA. Cluster analysis helped determine four shapes of horseshoe tears, each corresponding to a certain localization of VRA. Analysis of RRD risk, depending on the characteristics of the horseshoe tear, showed that the most significant risk factor for the development of RRD is the presence of a horseshoe tear with width greater than its length, which is characterized by a larger VRA area. The study established that the larger the horseshoe tear width and the smaller its length, the larger the VRA area and, consequently, the higher the risk of RRD development. Horseshoe retinal tears with a length-to-width ratio of less than 1/1 are the most dangerous in terms of RRD risk, which is important to consider when selecting the treatment tactics.

Large distal tear of aortic dissection

BACKGROUND: The traditional treatment for aortic dissections (ADs) is a proximal repair of AD, but the long-term prognosis of residual distal dissection is unsatisfactory. The distal aortic intimal tear of distal aortic segmental enlargement (DASE) is evaluated via its size, with risk assessment, and assessed its risk, which will provide clinicians with diagnosis and treatment direction. METHODS: We analyzed 419 ADs patients who underwent radiographic examination of the aorta between September 1999 and May 2014. We recorded the area of the aortic intimal tear and divided it into two groups (75 patients in DASE group and 344 patients in non-DASE group). Logistics regression analysis or natural logarithm transformation was used to explore the potential risk of remaining distal tears to DASE, while the Logistic multiple regress equations were used to find out the independent risk factors. RESULTS: The postoperative large tear was defined as short diameter ≥5.0 mm. The independent risk factors of DASE are as follows: Short diameter of postoperative tears (odds ratios [ORs], 1.10;95% confidence interval [CI], 1.02–1.19; P &lt; 0.0120); short diameter of the first tear after operation (OR, 1.12; 95% CI, 1.00–1.26; P &lt; 0.0580) and the existence of large tears (OR, 1.13; 95% CI, 1.01–1.26; P &lt; 0.0298). CONCLUSIONS: Our findings suggest that the size of the remaining tears and the existence of large tears are the key risk factors for patients with DASE. Patients with large remaining tears should be supervised regularly and treated timely.

Сравнение анатомической и функциональной эффективности радиального эписклерального пломбирования и комбинированной лазер-хирургической технологии при локальной macula-on отслойке сетчатки

Aim: to compare anatomical and functional outcomes of scleral buckling (SB) and combined laser and surgical intervention for focal macula-on rhegmatogenous retinal detachment (RRD). Patients and Methods: surgical outcomes of 84 patients (84 eyes) with focal RRD were analyzed. The study group included 43 patients (43 eyes) who underwent combined laser and surgical treatment for RRD that involved Nd:YAG laser excision of vitreoretinal adhesions followed by pneumoretinopexy and barrier laser photocoagulation. The control group that included 41 patients (41 eyes) was a retrospective sample of patients who underwent radial SB as described. Anatomical (the number of patients with attached retinal after a single surgical intervention and recurrence rate after surgery) and functional efficacy of the surgery were compared over a 2-year follow-up. Results: complete retinal reattachment was reported in 40 patients (93%) in the study group and 39 patients (95.1%) in the control group. Recurrent RD occurred in 3 patients (7.5%) in the study group and 4 patients (9.7%) in the control group over a 2-year follow-up. After 2 years, the final anatomical efficacy was 86% in the study group and 85% in the control group. Notably, no recurrent RD at the site of surgery was reported in the study group. Meanwhile, recurrent RD in the area of the primary retinal tear was reported in 1 patient in the control group. When comparing functional outcomes between the groups, a significant decrease in BCVA accounted for by an increase in astigmatism and spherical equivalent was reported after SB. Conclusions: the combined laser and surgical treatment is not inferior to SB in terms of anatomical efficacy and significantly superior to SB in terms of functional efficacy due to no changes in refractive indices after surgery. KEYWORDS: rhegmatogenous retinal detachment, optical coherence tomography, YAG laser retinotomy, vitreoretinal traction, treatment, recurrence. FOR CITATION: Taevere M.R., Kryl L.A.', Doga A.V., Shkvorchenko D.O. Anatomical and functional efficacy of radial scleral buckling and combined laser and surgical intervention for local macula-on retinal detachment. Russian Journal of Clinical Ophthalmology. 2023;23(3):119– 123 (in Russ.). DOI: 10.32364/2311-7729-2023-23-3-2.

Vision-Based Defect Measurement of Drilled CFRP Composites Using Double-Light Imaging

Drilling-induced defects in carbon fiber-reinforced polymers (CFRP) composite laminate can lead to the risk of aircraft structural failure and even aviation disaster. Measuring these defects is, then, inevitable for aerospace vehicles assembly. Tear is a representative drilling-induced delamination defect. But the most widely used measurement method is still based on human vision and vernier calipers. With low measurement efficiency and large measurement error, this is no longer suitable for industrialized large-scale production. Machine vision provides a new technology to address this problem. However, the semi-specular and textured surface around the drilled holes in CFRP laminates makes machine vision-based tear measurement difficult. To address these issues, we propose a novel automatic tear measuring system to obtain the tear point with maximum radial length (TPMRL). The method consists of three parts: (1) a double-light imaging frame is designed to illuminate the object hole under two different lighting conditions and acquire images; (2) a series of image processing procedures are proposed to accurately obtain inner hole information and tear edge information; (3) combined processing of inner hole information and tear edge information is performed to obtain the maximum radial length of the tear area (MRLTA). The experimental results show that the proposed system is able to measure the MRLTA and is superior to some existing relative approaches.

SPATIAL PATTERN OF RETINAL PIGMENT EPITHELIUM TEAR DEVELOPMENT AND PROGRESSION AFTER ANTIVASCULAR ENDOTHELIAL GROWTH FACTOR THERAPY FOR NEOVASCULAR AGE-RELATED MACULAR DEGENERATION.

The aim of this study was to demonstrate the spatial pattern of retinal pigment epithelium (RPE) tear development and progression after antivascular endothelial growth factor therapy for neovascular age-related macular degeneration. We retrospectively reviewed six eyes with neovascular age-related macular degeneration that showed RPE tears after administration of intravitreal antivascular endothelial growth factor agents and were followed up for 12 months. The patterns of RPE tear development and progression were evaluated by analyzing positional relationships among the locations of the choroidal neovascularization membrane and pigment epithelial detachment (PED) area at baseline and the tear area using spectral-domain optical coherence tomography, color photography, fluorescein angiography, and fundus autofluorescence images. Pretear OCT images revealed fibrovascular PED in all eyes, one of which showed complications of hemorrhagic PED after treatment. In five eyes, RPE tears developed at the PED edge located on the opposite side of the choroidal neovascularization membrane. In the eye showing hemorrhagic PED, the RPE tear developed along the wide area of the PED edge. The torn RPE monolayer contracted toward the side of the choroidal neovascularization membrane in all eyes, and RPE loss involved the fovea in five eyes that showed significantly worse visual acuity (VA) after 12 months in comparison with the baseline value before the tear (logMAR VA; 0.3 vs. 1.29; P < 0.02). The location of choroidal neovascularization membrane in PED determines the spatial pattern of RPE tear development and progression and helps to predict the visual outcome after RPE tears.

Unilateral Herpetik Keratitli Hastalarda Kuru Göz Parametrelerinin Değerlendirilmesi

Objective: Our aim in this study was to examine the tear parameters between affected and unaffected eyes of unilateral herpes simplex virus (HSV) keratitis patients, especially the meibomian glands status. Methods: The examinations and tear parameters including; tear film meniscus height (TMH) and area (TMA), non-invazive break up time (NIBUT), schirmer test, meibomian gland’s ekspressibility grade, drop out grade and microstructure of patients who were treated in our clinic with the diagnosis of unilateral herpetic endothelitis or herpetic stromal keratitis, and who had a quiescent period of about 3 months, were evaluated retrospectively. Results: The median age of our patients was 58.0 (55.25-72.25) years. The median NIBUT was 6.85 (4.62-17.0) sec. in affected eye and 15.85 (10.47-17.15) sec. in unaffected eye. NIBUT values were observed to be remarkable lower in the affected eye, although the change between groups was not statistically significant. Schirmer test values, TMH and TMA were similar between affected and unaffected eyes. Meibomian gland evaluations of affected and unaffected eyes were shown similar distribution across meibomian expressibility and drop out grades. Conclusion: We observed similar effects in both morphological and microstructural features of meibomian glands in both eyes. This condition makes us think that the developing dry eye disease in both eyes may be caused not only by neurosensorial anomalies but also by changes in the meibomian glands.

Determination of the optimal feed rate for step drill bit drilling CFRP pipe based on exit damage analysis

The non-axially distributed fibers in carbon fiber reinforced polymer (CFRP) pipes have buckling and bear the initial bending stress. Defects such as delamination, tear and burr at the hole exit are easy to occur in the drilling process. The feed rate is an important factor affecting the formation of defects. In this paper, the influence law of feed rate on exit delamination and tear is analyzed theoretically to prove the existence of the optimal feed rate. The optimal feed rate for step drill bit drilling CFRP pipe is obtained through experiments. Using step drill bit with a step ratio of 0.7 to drilling CFRP pipe, the influence of feed rates (0.01, 0.02, 0.03, 0.04, 0.06, 0.08, 0.1, 0.12 and 0.14 mm/r) on hole exit damage is studied to analyze the formation process of III-delamination and tear at a fixed spindle speed (3500 r/min). The results show that when the feed rate is less than 0.04 mm/r, the hole exit III-delamination mainly occurs in the secondary cutting stage of the step drill. The III-delamination range decreases with the increase of feed rate. When the feed rate is greater than 0.06 mm/r, the primary cutting stage is the main stage that leads to tear. In this stage, the thrust force is greater than 85.01 N, resulting in tear of mode I fracture. And the tear area increases with the increase of feed rate. Therefore, the hole with the least exit damage can be obtained by selecting the feed rate of 0.04 mm/r.

221. Efficacy of patch technique for dural tear repair

221. Efficacy of patch technique for dural tear repair

Countering choroid prolapse in corneo scleral repair.

Background:The video shows the meticulous repair of the corneoscleral tear along with management of the choroidal prolapse.Purpose:The video demonstrates the steps to establish the anatomical integrity of the globe and tips to avoid suture bites through the choroid in a corneo-scleral tear repair.Synopsis:Identification of important landmarks helps in the establishment of anatomical integrity. Therefore, the limbal area of tear is first sutured with 10-O nylon. The extent of wound onto the sclera is checked on the other end of the tear. Second limbal suture at the opposite end of the tear is taken, followed by dividing the corneal extent of tear by rule of half and segmental suturing with 10-O nylon. Then conjunctival peritomy is done to explore the scleral extent and the uveal tissue prolapse. Blunt and atraumatic back tip of Weckel sponge is used perpendicular to the plane of the sclera to push the choroid back aiding the scleral bite. Sclera is sutured with 9-O nylon suture taking care not to include the choroidal tissue. Air injection is done to check for any wound leak. Side port is hydrated, and corneal sutures are buried. The conjunctiva is secured with fibrin glue. Anterior chamber is formed with air bubble. Povidone iodine is instilled and BCL placed.Highlights:1. Suturing the landmark areas first; 2. Exploring the extent of wound; 3. Segmental suturing of the cornea; 4. Pushing the choroid back to avoid bites through it while suturing sclera; 5. Air injection to check for wound leaks; 6. Anterior chamber formation with air at the end.Video link: https://youtu.be/e5lEyLsQR3U

Effects of a Multi-Suckling System Combined With Enriched Housing Post-Weaning on Response and Cognitive Resilience to Isolation.

Improving welfare is still a critical issue in pig husbandry. Upgrades of the housing environment seem to be a promising solution to optimise resilience as a whole, and therefore improve animal welfare. The objective of this study was to evaluate the effect of an alternative housing system to enhance cognitive resilience and also to promote the pigs' welfare. A total of 96 piglets from two contrasted housing systems [alternative housing system (AHS) vs. conventional system (CONV)] was used. The major upgrades of the alternative system were multi-litter housing during lactation, delayed weaning, extra space allowance, and environmental enrichment from birth onwards. To estimate welfare, weight, and feed intake (as a general indicator of performances), the tear staining area (as a chronic stress indicator), behavioural postures, heart rate traits, and saliva cortisol concentration were measured over a 21 h-isolation. To assess cognitive resilience, the pigs were subjected to a maze with a social reward both before and after the isolation challenge and indicators of cognitive abilities were followed. The AHS pigs showed lower cortisol levels and tear staining area before the challenge, demonstrating overall better welfare due to the alternative housing conditions. During the challenge, AHS pigs had a lower heart rate, higher heart rate variability, and higher vagal activity than the CONV pigs, which might indicate a reduced sensitivity to the stressor. AHS pigs appeared to have a better long-term memory tested in a maze. Providing social and environmental enrichments, that fit the satisfaction of the essential needs of the pigs better, appears to be beneficial for pig welfare as a whole. Its effects on cognitive resilience still need to be proven.