Macroscopic Aspects Research Articles

Donor eligibility criteria and liver graft acceptance criteria during normothermic regional perfusion: A systematic review.

Acceptance of liver grafts from donations after circulatory death (DCD) largely remains a "black box," particularly due to the unpredictability of the agonal phase. Abdominal normothermic regional perfusion (aNRP) can reverse ischemic injury early during the procurement procedure, and it simultaneously enables graft viability testing to unravel this black box. This review evaluates current protocols for liver viability assessment to decide upon acceptance or decline during aNRP. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was used, and relevant literature databases were searched. The primary outcome consisted of criteria for liver graft viability assessment. Secondary outcomes included survival, primary nonfunction (PNF), early dysfunction, and biliary complications. A total of 14 articles were included in the analysis. In all protocols, a combination of criteria was used to assess suitability of the liver for transplantation. As many as 12 studies (86%) used macroscopic assessment, 12 studies (86%) used alanine transaminase (ALT) levels in perfusate, 9 studies (64%) used microscopic assessment, and 7 studies (50%) used lactate levels as assessment criteria. The organ utilization rate (OUR) was 16% for uncontrolled donation after circulatory death (uDCD) and 64% for controlled donation after circulatory death (cDCD). The most used acceptation criterion in uDCD is ALT level (31%), while in cDCD macroscopic aspect (48%) is most used. Regarding postoperative complications, PNF occurred in 13% (6%-25%) of uDCD livers and 3% (2%-4%) of cDCD livers. In uDCD, the 1-year graft and patient survival rates were 75% (66%-82%) and 82% (75%-88%). In cDCD, the 1-year graft and patient survival rates were 91% (89%-93%) and 93% (91%-94%), respectively. In conclusion, the currently used assessment criteria consist of macroscopic aspect and transaminase levels. The acceptance criteria should be tailored according to donor type to prevent an unacceptable PNF rate in uDCD and to increase the relatively modest OUR in cDCD.

Viability testing during liver preservation.

Viability assessment is one of the main indications for machine perfusion (MP) in liver transplantation. This review summarizes the rationale, evolution and limitations of proposed viability criteria and suggests a framework for future studies. Liver viability is most frequently assessed during normothermic MP by combining parameters relative to perfusate and bile composition, vascular flows and macroscopic aspect. Assessment protocols are largely heterogeneous and have significantly evolved over time, also within the same group, reflecting the ongoing evolution of the subject. Several recent preclinical studies using discarded human livers or animal models have explored other approaches to viability assessment. During hypothermic MP, perfusate flavin mononucleotide has emerged as a promising biomarker of mitochondrial injury and function. Most studies on the subject suffer from limitations, including low numbers, lack of multicenter validation, and subjective interpretation of some viability parameters. MP adds a further element of complexity in the process of assessing the quality of a liver graft. Understanding the physiology of the parameters included in the different assessment protocols is necessary for their correct interpretation. Despite the possibility of assessing liver viability during MP, the importance of donor-recipient matching and operational variables should not be disregarded.

Subchondral Drilling Independent of Drill Hole Number Improves Articular Cartilage Repair and Reduces Subchondral Bone Alterations Compared With Debridement in Adult Sheep

Background: Subchondral drilling is an established marrow stimulation technique for small cartilage defects, but whether drilling is required at all and if the drill hole density affects repair remains unclear. Hypotheses: Osteochondral repair is improved when the subchondral bone is perforated by a higher number of drill holes per unit area, and drilling is superior to defect debridement alone. Study Design: Controlled laboratory study. Methods: Rectangular full-thickness chondral defects (4 × 8 mm) were created in the trochlea of adult sheep (N = 16), debrided down to the subchondral bone plate without further treatment as controls (no treatment; n = 7) or treated with either 2 or 6 (n = 7 each) subchondral drill holes (diameter, 1.0 mm; depth, 10.0 mm). Osteochondral repair was assessed at 6 months postoperatively by standardized (semi-)quantitative macroscopic, histological, immunohistochemical, biochemical, and micro–computed tomography analyses. Results: Compared with defect debridement alone, histological overall cartilaginous repair tissue quality (P = .025) and the macroscopic aspect of the adjacent cartilage (P≤ .032) were improved after both drilling densities. Only drilling with 6 holes increased type 2 collagen content in the repair tissue compared with controls (P = .038). After debridement, bone mineral density was significantly decreased in the subchondral bone plate (P≤ .015) and the subarticular spongiosa (P≤ .041) compared with both drilling groups. Debridement also significantly increased intralesional osteophyte sectional area compared with drilling (P≤ .034). No other differences in osteochondral repair existed between subchondral drilling with 6 or 2 drill holes. Conclusion: Subchondral drilling independent of drill hole density significantly improves structural cartilage repair compared with sole defect debridement of full-thickness cartilage defects in sheep after 6 months. Subchondral drilling also leads to a better reconstitution of the subchondral bone compartment below the defects. Simultaneously, drilling reduced the formation of intralesional osteophytes caused by osseous overgrowth compared with debridement. Clinical Relevance: These results have important clinical implications, as they support subchondral drilling independent of drill hole number but discourage debridement alone for the treatment of small cartilage defects. Clinical studies are warranted to further quantify the effects of subchondral drilling in similar settings.

Macroscopic flexotronics enhanced controllable piezotronic-like response by flexual semiconductor devices

Interface engineering to modulate electronic transport is a pivotal technological and scientific endeavour. Herein, regardless of the macroscopic or microscopic aspects, we successfully demonstrate the piezotronic-like response in bulk bending centrosymmetric semiconductors single crystal Si strip with more flexibility and flexure in the home-built fixed platform. The flexoelectric potential and flexotronics could be dramatically enhanced by bending single crystal Si strip due to the change of the crystal structure and lattice constant. Besides, the flexoelectric polarization direction can be tuned by changing the bending direction. Moreover, the thinner the bending material is, the greater the SBH change rate. Theoretically, the working mechanism of flexoelectricity induced by the synergistic contribution consequence of the surface piezoelectric effect and bulk flexoelectric effect is elucidated.

Micro- and macroscopic aspects of the intermittent behaviors of granular materials related by graph neural network

Slowly sheared granular materials deform via intermittent slip avalanches, characterized by repetitive cycles of elastic loading interrupted by sudden stress drops. Although many mesoscopic models have been proposed to describe the relations between generic features in the macroscopic flow and microscopic plasticity, quantitative relations between microscopic plasticity and macroscopic stress drop remain elusive. We simulate the simple shearing of a three-dimensional dense granular assembly using the discrete element method. Microscopic plasticity is more spatially concentrated and tends to generate larger active clusters with the increase of the magnitude of stress drop. The initialization, development, and aggregation of microscopic plasticity constitute the microscopic origin of macroscopic slip avalanches. We then utilize the graph convolution neural network to establish a quantitative relation between microscopic plasticity and macroscopic stress drop. Further analysis on the number of convolution layers reveals that the spatial extent of microscopic plasticity determines the magnitude of macroscopic stress drop.

On the Mechanism of Cocrystal Mechanochemical Reaction via Low Melting Eutectic: A Time-Resolved In Situ Monitoring Investigation

Mechanochemistry has become a sustainable and attractive cost-effective synthetic technique, largely used within the frame of crystal engineering. Cocrystals, namely, crystalline compounds made of different chemical entities within the same crystal structure, are typically synthesized in bulk via mechanochemistry; however, whereas the macroscopic aspects of grinding are becoming clear, the fundamental principles that underlie mechanochemical cocrystallization at the microscopic level remain poorly understood. Time-resolved in situ (TRIS) monitoring approaches have opened the door to exceptional detail regarding mechanochemical reactions. We here report a clear example of cocrystallization between two solid coformers that proceeds through the formation of a metastable low melting binary eutectic phase. The overall cocrystallization process has been monitored by time-resolved in situ (TRIS) synchrotron X-ray powder diffraction with a customized ball milling setup, currently available at μSpot beamline at BESSY-II, Helmholtz-Zentrum Berlin. The binary system and the low melting eutectic phase were further characterized via DSC, HSM, and VT-XRPD.

Chitosan and chitin production and extraction in isolates of Cunninghamella sp.

The use of fungi to obtain chitin and chitosan has advantages such as handling, extraction, and production control, thus allowing to generate high quality chitosan. This study aimed to isolate and identify strains of Cunninghamella spp., and assess the production of biomass, chitin, and chitosan. We determined the macroscopic and microscopic phenotypic aspects of the superiors, mycelial growth rate index, consumption of glucose and nitrogen, as well as the pH variation, and the production of biomass, chitin, and chitosan. After assessing the mycelial growth speed index, considered fast, we found that the UFT-Ce08 and UFT-Ce09 isolates showed a higher growth speed. Therefore, we assessed the sporulation of the isolates, and all of them reached the concentration of 106 spores mL-1 in the period of 96 hours. The YPD was considered ideal for biomass production because it promotes an efficient consumption and synthesis of organic compounds by microorganisms. The assessment of the biomass production and the chitin and chitosan yield of nine isolates and the reference strain showed that the UFT-Ce08 isolate had the highest amount of biomass, the UFT-Ce11 isolate had the highest chitin yield, and despite having the second smallest biomass, the UFT-Ce09 isolate had the highest chitosan yield. Seven isolates showed higher chitosan yield than the reference strain. Therefore, chitosan production from this fungus can be further optimized to improve yield on a large-scale production. Chitosan production from this fungus can be further optimized to improve yield in large-scale production

Mineralogical and physico-chemical characterization of bentonite materials from the Oued Zemmour area (Oriental Rif, Nador-Morocco): Valorization in ceramic field

The Oued Zemmour deposit is associated to Neogene volcanism in the Kert basin, Nador area (Morocco), and thus one of the numerous bentonite occurrences in the Gourougou volcano's region. To assess their potential use, this article examines the Oued Zemmour bentonite deposit, helping with mineralogical, physicochemical, morphological, geotechnical analyses and ceramic performances. Mineralogical associations are essentially made of montmorillonite, K-feldspars and plagioclase, associated with lower quantities of calcite, dolomite and quartz. The main chemical composition in oxides is SiO2 and Al2O3. Geotechnical results show that the swelling index and Atterberg limits widely vary within the deposit, but all studied samples display high plastic and swelling qualities. The 10 representative bentonite samples of the area (Oz 1–Oz 10) were subjected to a ceramic technological assessment, and all samples have displayed good quality after dry pressing method and sintering at 1000°C without any defect or cracks (except for Oz 4, Oz 5, and Oz 8 samples). Therefore, two mixtures (Oz M and Oz M1) have been developed from the samples studied, using the same manufacturing protocol. The obtained ceramics were evaluated by studying their morphological structure and macroscopic aspect, as well as their bulk density, porosity, water absorption, shrinkage and tensile strength properties.

Macroscopic aspects of glenohumeral synovitis are related to rotator cuff tear severity.

The microscopic pattern of inflammatory mediators associated with rotator cuff pathology is well documented; however, little is known regarding the contemporary presence of macroscopic inflammatory joint involvement. Our aim was to investigate shoulder synovitis in a large group of patients with different sized rotator cuff tears (RCTs) and to correlate the degree of macroscopic inflammatory changes of the glenohumeral joint with RCT severity. A total of 296 consecutive patients (169 F, 127 M; mean age ± standard deviation: 60.75 ± 7.91) submitted to arthroscopic RCT repair were enrolled. RCT was classified intraoperatively. Glenohumeral synovitis was investigated according to 4 parameters (Davis classification 2017: capsule color, villous projections, capillaries, and axillary recess). A total score was calculated, and a 3-grade severity scale was introduced. Statistics was performed. Intraclass correlation coefficient (ICC) results show good to excellent reliability: capsule color (ICC: 0.95; 95% confidence interval [CI]: 0.89-0.99), villous projections (ICC: 0.90; 95% CI: 0.85-0.95), capillaries (ICC: 0.91; 95% CI: 0.86-0.95), and axillary recess (ICC: 0.55; 95% CI: 0.80-0.89).The synovitis total score was found to be 1.47 ± 1.16, 2.86 ± 1.84, and 3.99 ± 1.64 in patients with type I, II, and III RCTs, respectively. A significant difference was found between groups (P < .001). The prevalence of all the examined parameters was found to be significantly different between the different sized RCT groups (capsule color: P < .001; villous projections: P < .001; capillaries: P < .001; and axillary recess: P < .001). According to a 3-grade severity scale, the prevalence of absent, mild, and severe glenohumeral synovitis significantly differed between the RCT severity groups (P < .001). The present study demonstrated that synovitis is a constant finding of rotator cuff pathology; it is present in 75% of patients with RCTs and correlates with tear severity. Whether synovitis is the cause or effect of RCT is still questionable. Further studies are also needed to better understand its role as a pain generator, as documented in other diseases.

Proposal for Simplified Endoscopic Standardized Grading of Central Airway Complications After Lung Transplantation According to the Long-Term Prognosis Value of the Current MDS Classification

<h3>Purpose</h3> The MDS classification (<i>i.e.</i> Macroscopic aspect, Diameter, Suture) allows an endoscopic grading of bronchial complications after lung transplantation. We aimed to determine the long-term prognosis value of the MDS airway evaluation after lung transplant and to propose a new organization in prognostic stage of the MDS classification. <h3>Methods</h3> We performed a retrospective monocentric cohort study of the consecutive patients who underwent a single or double lung transplant between the January 2015 and December 2021. We analyzed the prospectively evaluated MDS status at day 7, 28 and 90 after transplantation and the long term follow-up. Analyzed outomes were overall survival (OS), chronic lung allograft dysfunction (CLAD) and airways complications (AC) defined by reoperation or rigid bronchoscopy requirement. <h3>Results</h3> During the study period 221 lung transplants were performed. 437 bronchial anastomoses were analyzed at day 7, 378 at day 28 and 336 at day 90. At day 7, patients with extremely severe and extensive necrosis of the bronchial mucosa (M3d) presented worse OS (p<0.01); While extensive ischemic or necrosis bronchial mucosa (M3c) was associated with AC (p<0.01). At day 28, patients with bronchial mucosa necrosis distal to the anastomosis (M3b, 3c and 3d) presented a worse OS (all p≤0.01) and AC (all p<0,01). At day 90, patients who still presented M3c presented worsened OS (p<0.01) and increased risk of AC (p<0.01). Separate analysis of patients with M3b, c and d (at day 28 and 90) showed similar relationship with OS, CLAD and AC (all p<0.01); as far as patients with M0 and M1 had the same prognosis in terms of OS (all p=NS), CLAD and AC (all p=NS), it was the same for M2 and M3a (all p=NS). Therefore, we have reorganized the MDS classification in 3 stages: G1 for M0/M1 a, b, c, d; G2 for M2 a, d, c, d/M3 a; G3 for M3b, c, d. We have compared the 3 groups of patients with G1 as reference. Stage G3 at day 7 was associated with AC (p<0.05) while at days 28 and 90 it was associated with OS, AC and CLAD (all p<0.05) <h3>Conclusion</h3> The endoscopic MDS grading system can be simplified into 3 groups providing prognostic risk stratification of OS, AC and CLAD development after lung transplantation.

Is CEES a good analog of sulfur mustard? Macroscopic aspect, histology, and molecular biology comparisons between sulfur mustard and CEES-induced skin lesions

Sulfur mustard (SM) is a chemical blistering warfare agent affecting multiple organs. SM is an ongoing chemical threat in addition to the accidental risk associated with World War I buried shells. As no specific treatments are available, only symptomatic therapies can be used.To test new medical countermeasures in standard laboratories, analogs such as 2-chloroethyl ethylsulfide (CEES) are currently used, although only a few studies compare its clinical effects with SM. In the present paper, skin lesions induced by SM and CEES are compared in terms of their macroscopic aspects, histology, and molecular biology to evaluate the pertinence of CEES as a SM analog. For this purpose, an in vivo model of CEES vapor exposure, similar to that of SM, is described in this paper. Resultsshowed similar skin lesions with CEES and SM but with slight differences in the apparition delay and intensity of the lesions. Indeed, SM induced earlier, deeper, and stronger lesions. However, the same healing status was observed at the end of the study period (14 days).In conclusion, CEES appears a relevant analog of SM, leading to similar skin lesions. The CEES vapor exposure model therefore seems suitable for testing new medical countermeasures.

Quantifying Computed Tomography of Basalt Fiber-Reinforced Concrete under Unconfined Compression

The macroscopic aspects of adding basalt fiber (BF) to concrete has been the subject of studies that document great increases in compression strength. Research into the microscopic aspects of the reinforcement mechanism is still in an exploratory stage, and the quantitative analysis and visual observation of fibers in the concrete matrix are difficult. In this paper, the reinforcement effect of fiber on concrete is studied by means of computed tomography (CT) scanning technology and digital image processing (DIP) technology, combined with the macro-mechanical properties obtained from the unconfined compression strength test, and quantitative analysis from the micro point of view. At the same time, the fiber visualization is realized with the help of Avizo. The results show that with the increase in fiber dosage, the peak stress of concrete first increases and then decreases. When the fiber dosage is 3 kg/m3, the peak stress is 44.4 MPa, which is 41.85% higher than that of ordinary concrete. Additionally, the proportion of macropores is the least, which is the best fiber dosage. It is found that when the fiber dosage is 3 kg/m3, the angular distribution of φ is relatively uniform, and the uniform distribution of fibers forms a dense network structure, which significantly increases the peak stress of concrete. However, when the fiber dosage is too high, it will lead to the accumulation of fibers and produce macropores, and these excess fibers mainly appear in the horizontal direction and do not contribute to the compression strength.

Bioactive Bacterial Nanocellulose Membranes Enriched with Eucalyptus globulus Labill. Leaves Aqueous Extract for Anti-Aging Skin Care Applications.

Bacterial nanocellulose (BNC) membranes, with remarkable physical and mechanical properties, emerged as a versatile biopolymeric carrier of bioactive compounds for skin care applications. In this study, BNC membranes were loaded with glycerol (as plasticizer and humectant agent) and different doses (1–3 μg cm−2) of an aqueous extract obtained from the hydro-distillation of Eucalyptus globulus Labill. leaves (HDE), for application as sheet facial masks. All membranes are resistant and highly malleable at dry and wet states, with similar or even better mechanical properties than those of a commercial BNC mask. Moreover, the HDE was found to confer a dose-dependent antioxidant activity to pure BNC. Additionally, upon 3 months of storage at 22–25 °C and 52% relative humidity (RH) or at 40 °C and 75% RH, it was confirmed that the antioxidant activity and the macroscopic aspect of the membrane with 2 μg cm−2 of HDE were maintained. Membranes were also shown to be non-cytotoxic towards HaCaT and NIH/3T3 cells, and the membrane with 2 μg cm−2 of HDE caused a significant reduction in the senescence-associated β-galactosidase activity in NIH/3T3 cells. These findings suggest the suitability and potential of the obtained membranes as bioactive facial masks for anti-aging applications.

Planned complex suicide combining pistol head shot and train suicide and Virtopsy examination

• What resolution is necessary for forensic triage post-mortem CT • How to search for and identify gunshot injury to the head in apparent case of train suicide • Comparison of CT and macroscopy of bone fragments This case report focuses on the findings in what appeared to be a planned complex pistol head shot and train suicide. The post mortem computed tomography (PMCT) scan in this instance yielded two interesting skull fragments among the many fragments of a highly fragmented body and head. These two fragments, based on initial resolution, appeared to show findings consistent with a firearm shot to the head. Upon reconstruction of higher resolution data, the necessary discrimination of non-gunshot related semi-circular fragment rims and firearm-related beveling matched the macroscopic aspect of the skull fragments. As a first lesson to be learned, a thorough examination of PMCT data in relatively high degrees of fragmentation may have to inspect all bone edges also for relatively subtle changes, possibly indicative of sharp force trauma or gunshot trauma. To that end, individual bone fragments should be placed on the scanner table carefully and with proper spacing, to expose their edges. Only this allows to capture data that avoids edge overlaps or edge collisions and that allows for optimal checking of the edges of all bone fragments for possible semicircular defects in the PMCT data. A second technical lesson to be learned is that particularly in instances of high fragmentation of at least parts of a body, resolution may have to be at least as good as maximally achievable. To that end, availability of the raw data to reconstruct images with maximal image quality rather than using a trade-off between lesser cost and lesser yield may be a key issue. A third lesson to be learned is that findings in relatively highly fragmented bodies as consequence of an apparent form of injury - fire/thermal, fall from great height, collision with a train - for other forms of trauma - sharp force trauma, firearm injury - may have to interpreted with caution, particularly with regard to what can be ruled out.

Optimisation of variable speed limits at the freeway lane drop bottleneck

ABSTRACT The primary objectives of this study were to use variable speed limits (VSL) upstream of freeway lane drop to maintain capacity and reduce congestion. As driving behaviours are the main reasons leading to capacity drop and the microscopic simulation can reflect driving behaviours precisely, microscopic simulations were first used to test lane drop scenarios. The objective function and constraints determined according to traffic engineering practice were optimised using a modified genetic algorithm (GA) based on microscopic simulation to get the optimal speed limit combination. The modified GA can guarantee the solution diversity and optimal results. Then, the cell transmission model, a macroscopic flow model, was used to crosscheck the simulated results. Both microscopic and macroscopic analysis results demonstrated that VSL could only improve lane drop traffic efficiency if speed limits were set appropriately. This study provided a new process from microscopic to macroscopic aspects for analysing traffic problems.

Effects of sub-acute co-exposure to WIFI (2.45GHz) and Pistacia lentiscus oil treatment on wound healing by primary intention in male rabbits.

BackgroundThe bioeffects of WIFI on cutaneous wound healing remains unexplored. In addition, several medicinal plant products including lentisk oil have been shown to interfere with wound healing process. Since the use of this oil is increasing, the co‐exposure (WIFI‐Lentisk oil) assessment is of paramount importance.ObjectivesWe aimed in the present study to investigate the effects of WIFI exposure as well as the application of Pistacia lentiscus oil on sutured wounds (SW).MethodsNew Zealand male rabbits (n = 24) were used and randomly divided into four groups of six animals each: a control group (SW) and three experimental groups (i) a first group exposed to WIFI (2.45 GHz, 6 h/day) during 16 days (SWW); (ii) a second group exposed to WIFI (2.45 GHz, 6 h/day) during 16 days and treated with lentisk oil (SWWL) and (iii) a third group not exposed to WIFI but treated with lentisk oil (SWL). The wound healing was evaluated by monitoring clinical parameters (temperature, food intake, relative weight variation, and macroscopic aspect) and histology.ResultsThe mean food intake was higher in the SWWL group compared to the three other groups (p < 0.001) and higher in the SWL group compared to the SW group (p = 0.014). The exposition to WIFI (SWW group) or lentisk oil application (SWL group) can promote the collagen deposition and ameliorate the general aspect of wounds. By contrast, the co‐exposure to WIFI and lentisk oil (SWWL) results in antagonist effects and extends the inflammatory phase of wound healing.ConclusionsWounds treated topically with Pistacia lentiscus oil should not be exposed to WIFI.

The hidden aspect of carotid lesions in traffic accidents: A little-known phenomenon

Vascular injuries that occur during traffic accidents are a commonly neglected aspect that can add more detail to the framework of a case. In this study, we analysed a case series of 150 traffic accidents, 39 of which were marked by microscopically identifiable vascular lesions. The purpose was to identify the presence of carotid injuries in individuals who died due to traffic accidents and had nonpenetrating trauma of the neck. We focused on the discrepancies regarding the macroscopical aspect and the histology and demonstrated how histological analysis of the carotids in cases of trauma can reveal injuries that are attributable to the trauma itself. We conducted a histological analysis of the lesions to describe their distribution and type and investigate potential correlations. The study offers insight on how to examine road accidents that involve traumatic injury of the carotid arteries. Indeed the main task of the forensic pathologist in the case of death is to establish the existence of a causal relationship between the micro- or macroscopic alterations observed in the autopsy and the traumatic event that led to the death of the subject. Thus, further morphological elements were provided to the forensic practitioners that may reveal injuries attributable to the trauma itself and should be evaluated in cases of trauma in traffic accidents.

Mechanical behaviour and energy evolution of polyurethane-mixed ballast under revised bonding constitutive model

The bonding contact presents complex modes in polyurethane-mixed ballast. The commonly used parallel bond model is revised and four different contact models are developed including Ballast-Ballast Contact Bonding, Ballast-Ballast Noncontact Bonding, Ballast-Sleeper Contact Bonding, and Ballast-Sleeper Noncontact Bonding. The mechanical behaviour and energy evolution of polyurethane-mixed ballast with various amounts of glue are studied from the macro and mesoscopic properties. Results show that the elastic strain energy has always been the main form in polyurethane-mixed bed, followed by viscous strain energy, frictional energy, and damping energy. Compared with the common ballast bed, there are more contacts in polyurethane-mixed ballast bed and, when more glue is used, the amount of contacts is further increased while the maximum contact force is reduced. After bonding, the amount of contacts is significantly increased and all forms of energy become more evenly distributed at different surfaces of the sleeper. The kinetic energy of polyurethane-mixed ballast fluctuates with smaller amplitude and convergences more quickly under cyclic loading, which is reflected in the macroscopic aspect that the settlement of polyurethane-mixed ballast bed is relatively small and can be fast completed.

Descemet’s membrane rupture due to forceps injury: macroscopic aspect by anterior segment optical coherence tomography

AbstractPurposeTo describe corneal changes after birth trauma from forceps delivery, using anterior segment optical coherence tomography (AS‐OCT), in order to reduce the risk of potential anisometropic amblyopia.MethodsA 73‐year‐old female patient came to the ocular surface section consulting for dry eye disease symptoms. At the slit lamp examination, a vertical endothelial stria was observed in the right eye. After an exhaustive anamnesis, the patient referred having a traumatic birth in which forceps had been used.ResultsAn AS‐OCT was performed, showing a vertical rupture in the Descemet membrane secondary to traumatic birth with forceps.ConclusionsDescemet’s membrane rupture can cause corneal oedema which usually clears over time, but those ruptures often persist. The residual corneal changes can result in anisometropia and the main cause of vision loss after such injury is anisometropic amblyopia. The AS‐OCT is a useful diagnostic tool to detect these alterations at early stages.BibliographySarma P, Borgohain M, Tayab S, Sangma CA. Descemet's membrane rupture secondary to forceps‐induced birth injury. Indian J Ophthalmol. 2020;68(10):2253. https://doi.org/10.4103/ijo.IJO_149_20Alobaidy R, Srinivasan S. Forceps‐induced birth injury to the cornea. BMJ Case Rep. 2014;2014:bcr2013201786. Published 2014 Apr 9. https://doi.org/10.1136/bcr‐2013‐201786

Treatment of experimentally induced partial-thickness burns in rats with different silver-impregnated dressings.

To evaluate the morphometric, macroscopic and microscopic aspects of experimentally induced partial-thickness burns in rats treated with different silver-based dressings. Wistar rats were used, divided into six treatments: saline (NaCl 0.9%); silver sulfadiazine 1%; Silvercel; Mepilex Ag; Aquacel Ag and Acticoat. The animals were monitored daily and euthanized at 7, 14 and 30 days after injury induction (DAI). At 7 DAI, necrosis/crust was greater in control, silver sulfadiazine and Mepilex Ag treatments, granulation tissue was induced by Aquacel Ag, polymorphonuclear infiltrate (PMN) infiltration was intensified by Mepilex Ag; mononuclear infiltrate (MN) infiltration and angiogenesis were increased by Silvercel. At 14 DAI, hemorrhage was decreased by Silvercel and Mepilex Ag, PMN infiltration increased by Acticoat. At 30 DAI, angiogenesis was greater in the Acticoat treatment and fibroblasts were increased by Acticoat and Mepilex Ag. Collagen was induced at 14 DAI by silver sulfadiazine and Aquacel Ag and, at 30 DAI, by silver sulfadiazine and Silvercel treatments. Silvercel and Acticoat presented better results than the other products. However, all the dressings were better than the control at some point during the process, and may contribute to the healing of partial thickness burns. Silvercel and Aquacel Ag treatments induced better cosmetic outcomes regarding wound closure and scarring.