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The main goal of this paper is to reveal the symplectic structure related to renormalization of circle maps with breaks. We first show that iterated renormalizations of r circle diffeomorphisms with d breaks, r > 2 , with given size of breaks, converge to an invariant family of piecewise Möbius maps, of dimension 2 d. We prove that this invariant family identifies with a relative character variety χ (π 1 Σ , PSL (2 , ℝ) , h) where Σ is a d -holed torus, and that the renormalization operator identifies with a sub-action of the mapping class group MCG (Σ). This action allows us to introduce the symplectic form which is preserved by renormalization. The invariant symplectic form is related to the symplectic form described by Guruprasad et al. [Group systems, groupoids, and moduli spaces of parabolic bundles, Duke Math. J.89(2) (1997) 377–412], and goes back to the earlier work by Goldman [The symplectic nature of fundamental groups of surfaces, Adv. Math.54(2) (1984) 200–225]. To the best of our knowledge the connection between renormalization in the nonlinear setting and symplectic dynamics had not been brought to light yet. [ABSTRACT FROM AUTHOR]

Photon-counting computed tomography (PCCT) has shown promising advancements in abdominal imaging in clinical use. Though more peer-reviewed primary literature is needed, this commentary explores PCCT's potential applications, focusing on enhancing diagnostic accuracy, optimizing radiation dose management, and improving patient care. PCCT offers improved spatial and contrast resolution, lower image noise, and reduced radiation dose. Increased spatial resolution provides better detail in abdominal imaging, aiding in the detection of small lesions and subtle pathological changes. However, this generates more images per scan, raising concerns about "image overload" in PACS, potentially leading to longer reading times and increased stress for radiologists. PCCT's improved contrast resolution enhances tissue differentiation, reducing the need for intravenous contrast agents. The technology's advanced tissue characterization provides several advantages, such as non-invasive and opportunistic liver disease evaluation and improved differentiation of renal and adrenal masses. PCCT's optimized radiation dose management is crucial for patients requiring frequent scans. Enhanced diagnostic accuracy through spectral information aids in tissue differentiation, improving confidence in diagnoses. Streamlined workflows, particularly in emergency settings, and oncologic imaging, are potential benefits, reducing the need for additional imaging studies. Future integration of PCCT into clinical practice requires collaboration, education, and research to fully harness its potential, ensuring optimized abdominal imaging and improved patient care., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Institute of Radiology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Introduction: Preoperative carbohydrate intake is essential to enhance postoperative recovery. However, its safety for individuals with obesity remains unclear. This study investigated the safety of preoperative carbohydrate consumption compared to water intake in obese populations through gastric volume assessment., Methods: A prospective randomized crossover study enrolled 30 healthy volunteers aged 18-65 years with a body mass index ≥ 30 kg/m 2 , following a minimum 6-h fast. The participants received either 400 ml of a carbohydrate drink (group C) or water (group W). Gastric ultrasonography, blood glucose level, hunger, and thirst assessments were conducted at baseline (T) and various time points (T2 to T6). The protocol was repeated with reverse interventions at least 1 week later., Results: Group C had significantly higher gastric volume at T3, T4, and T5 compared to group W, with a prolonged time to empty the gastric antrum (94.4 ± 28.5 vs. 61.0 ± 33.5 min, 95% CI 33.41 [17.06,24.69]). However, glucose levels, degrees of hunger, and thirst showed no significant differences between the groups., Conclusion: Administering 400 ml of preoperative carbohydrates to healthy obese individuals 2 h preoperatively is safe and comparable to water intake. These findings support the integration of carbohydrate loading into perioperative care for obese individuals, consistent with the enhanced recovery after surgery protocols. Further research is warranted to refine preoperative fasting protocols and improve surgical outcomes in this population., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: With the increasing incidence of hip fractures in older adults, hip replacement with a cemented femoral stem has become a viable treatment option. However, concerns regarding potential complications, particularly bone cement implantation syndrome (BCIS), especially in patients with preexisting medical conditions, have prompted orthopedic surgeons to explore alternative approaches., Objective: The research question of this retrospective study is whether BCIS incidence in patients with preexisting heart disease undergoing cemented bipolar hemiarthroplasty is higher than that of patients without preexisting heart disease., Methods: We retrospectively analyzed data from 311 patients undergoing cemented bipolar hemiarthroplasty, including 188 without preexisting heart disease and 123 with heart disease. Anesthetic records were reviewed to assess parameters related to BCIS. BCIS severity was graded systematically, emphasizing key metrics, such as hypotension, arterial desaturation, and the loss of consciousness., Results: Among the patients, no perioperative deaths occurred. Grade 1 BCIS was observed in 13 patients (4.18 %), without instances of grade 2 or 3. Notably, grade 1 BCIS was observed in only 2 patients with preexisting heart disease (1.63%) and 11 patients (5.85%) without preexisting heart disease., Conclusion: BCIS incidence after cemented bipolar hemiarthroplasty was minimal, with a predominantly low severity. Importantly, preexisting heart disease did not pose a significant increase in the risk of BCIS. This finding confirms the safety of cemented bipolar hemiarthroplasty in older adults., Level of Evidence: III., Competing Interests: The authors declare that they have no competing interest.

Total knee arthroplasty faces challenges in the management of medial uncontained tibial defects, affecting prosthesis stability and implant survival. The use of screws and bone cement is a preferred approach; however, optimal screw insertion techniques lack consensus in the existing literature. The present study aimed to address this gap by exploring optimal screw and cement placement strategies, focusing on their biomechanical implications. The present study conducted a finite element analysis using a knee prosthesis model with a defined uncontained tibial defect. Various parameters were systematically adjusted, including the number of screws (1, 2 or 3 screws), screw lengths (10, 18, 30 or 40 mm), lateral-medial screw positions (2, 4 or 6 mm laterally) and abduction rotation angles (0, 5, 10 or 15 degrees). These adjustments were made to evaluate their specific and combined impacts on the vertical displacement and abduction angles of the tibial tray. The results revealed that incorporating three-screw reinforcement markedly reduced vertical displacement, while the single screw in the middle position exhibited superior performance in preventing the deformation of abduction angles compared to scenarios with two screws at anterior and posterior positions without a middle screw. Longer screws and smaller abduction angles contributed to decreased movement of the tibial component. Furthermore, the lateral adjustment of the screw position led to an increase in vertical displacement values, reaching ~1.5% when shifted 6 mm laterally. On the whole, the finite element analysis in the present study suggests that, for the treatment of medial uncontained tibial defects, three-screw reinforcement is advantageous for larger defects. Longer screws and a smaller abduction angle are deemed favorable. Moreover, the results underscore the superiority of medial screw placement over lateral placement. It is imperative to note that further clinical validation is essential to corroborate the biomechanical implications observed herein., Competing Interests: The authors declare that they have no competing interests., (Copyright: © 2024 Kwanyuang et al.)

Background: Total knee arthroplasty (TKA) is a routine orthopedic procedure often associated with significant postoperative pain. Efficient pain management is paramount for patient recovery, with nonsteroidal anti-inflammatory drugs (NSAIDs) being a common choice. Nevertheless, the specific NSAID and its dosing regimen can have varying impacts on outcomes., Methods: In this retrospective cohort study spanning from January 2016 to December 2020, we analyzed patients who underwent TKA. These patients were divided into two groups: one receiving preemptive low-dose ketorolac (15 mg) followed by 15 mg every 6 h for 48 h, and the other receiving parecoxib (40 mg) every 12 h for the same duration. We assessed pain scores, opioid consumption, and monitored adverse events., Results: Our findings reveal that ketorolac yielded superior results compared to parecoxib. Specifically, patients receiving ketorolac reported significantly lower Visual Numeric Rating Scale (VNRS) scores at 8- and 20-h post-surgery. This trend was further confirmed by linear mixed models ( p = .0084). Additionally, ketorolac was associated with reduced opioid consumption during the initial 24 h. Importantly, the rates of adverse events were comparable between the two groups., Conclusion: The utilization of preemptive low-dose ketorolac demonstrates promising potential in bolstering pain control within the initial 24 h post-TKA, potentially reducing the need for opioids. However, further exploration is required to thoroughly assess its prolonged analgesic effects and safety across various surgical contexts. These investigations could provide invaluable insights for optimizing pain management protocols., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Lumpy skin disease (LSD) is a viral infection that impacts the cattle industry. The most efficient approach to prevent disease involves the utilization of live-attenuated LSD vaccines (LAVs), which stands out as the most successful method. However, LAVs might be subjected to changes to their genomes during replication that increase viral infectivity or virulence. The objective of this study was to monitor alterations in the genetic characteristics of the lumpy skin disease virus (LSDV) in beef cattle following the administration of LAVs in Lopburi Province of Central Thailand. A total of four skin samples from LSD cases were collected from non-vaccinated animals that exhibited LSD clinical symptoms from two distinct districts, spanning three subdistricts within the region. The samples of cattle were analyzed using real-time PCR targeting the LSDV074 p32 gene, the virus was isolated, and the entire genome sequences were evaluated through a single nucleotide polymorphisms (SNPs) analysis, and phylogenetic trees were assembled. The investigations revealed that LSDVs from two isolates from Chai Badan district exhibited significant mutations in the open reading frame (ORF) 023 putative protein, while another two isolates from Lam Sonthi district had a change in the untranslated region (UTR). For a result, the most proficient disease diagnosis and control should be evaluated on viral genetics on a regular basis.

Purpose: Periarticular infiltration (PI) is a common procedure during total knee arthroplasty (TKA) for postoperative pain management. This retrospective, case-matched study aimed to evaluate the effectiveness of PI with dexamethasone and bupivacaine in combination with an adductor canal block (ACB) and compare it with that of ACB alone in reducing postoperative pain in patients with TKA., Methods: Data were collected from 66 patients who underwent TKA performed by a single surgeon. Thirty-three of them received ACB + PI, and 33 received ACB alone. However, both groups underwent identical surgical techniques and postoperative care protocols. The pain scores and fentanyl consumption of the two groups were compared., Results: The ACB + PI group had significantly lower pain scores than the ACB alone group at 8, 16, 24, and 48 hours postoperatively ( p =0.033, 0.004, 0.038, and 0.049, respectively). The percentage of patients requiring fentanyl as a rescue medication was significantly higher for the ACB alone group (90.9%) than for the ACB + PI group (69.7%, p =0.03). The total fentanyl consumption was also lower for the ACB + PI group ( p < 0.001)., Conclusion: The periarticular injection of the combination of dexamethasone and bupivacaine plus ACB was more effective than ACB alone in reducing postoperative pain and fentanyl consumption in patients undergoing TKA. Further studies comparing different doses of dexamethasone or other cocktail regimens may provide additional insights into this approach., Competing Interests: The authors declare that they have no conflicts of interest with respect to the research, authorship, and/or publication of this article., (Copyright © 2023 Varah Yuenyongviwat et al.)

Cigarette smoke contains many chemicals, including nicotine, which is harmful and can cause health problems such as carcinogenesis disease, cardiovascular, respiratory, renal, and reproductive systems. Removal of nicotine from mainstream smoke can be done through adsorption with filters or solid adsorbents. In this study, we explored the use of activated carbons for the removal of nicotine from cigarette mainstream smoke. Activated carbons were prepared from dried hemp (Cannabis sativa) stem at an activation temperature of 350-550 °C using phosphoric acid as an activating agent. The results showed that the activated carbons with variable surface functional groups and porosity exhibited high efficiency for nicotine adsorption, removing 68-88% of nicotine from cigarette mainstream smoke. Through X-ray photoelectron spectroscopy and temperature-programmed desorption analyses, we identified that oxygen-containing functional groups, particularly carboxylic groups, exhibited a superior ability to adsorb nicotine. The computational analysis with DFT simulations further supported the importance of oxygen-containing surface functional groups in facilitating nicotine adsorption, with the carboxylic group providing the lowest adsorption energy among other functional groups., (© 2023. Springer Nature Limited.)

Background: Cemented long-stem hip arthroplasty is a treatment of choice for the pathological fractures of the femoral neck with metastatic lesions and the prevention of further fracture caused by metastasis progression., Objective: The present study was an evaluation of the outcome after treatment of metastatic femoral neck fractures with cemented standard-length hemiarthroplasty., Methods: We retrospectively studied 23 patients in whom the pathological fractures of the femoral neck with metastatic lesions were diagnosed. All patients underwent hemiarthroplasty with cemented standard-length femoral stems. The demographic data of the patients and clinical outcomes were obtained from an electronic medical database. Metastasis progression-free survival time was analyzed via the Kaplan-Meier curve., Results: The mean age of the patients was 51.5 ± 11.7 years. The median duration of follow-up was 6.8 months (interquartile range, 5-22.6 months). Four patients exhibited tumor progression according to radiographic evaluation, but no patients had new fractures in the same bone or needed reoperation. The Kaplan-Meier curve revealed that 88.2% (74.2,100) of femurs demonstrated 1 year radiographic progression-free survival and 73.5% (49.4,100) demonstrated 2 year progression-free survival., Conclusions: Our study demonstrated that the use of cemented standard-length stems in hemiarthroplasty for pathological fractures of the femoral neck with metastatic lesions is safe, and the rate of reoperation was low. We believe that this prosthesis is optimum for treatment in this group of patients because the length of survival in patients is expected to be short and the rate of metastasis progression in the same bone is low., Competing Interests: The authors declare that they have no competing interests.

Background: While radiography remains essential in the initial evaluation of bone lesions, tissue biopsy or further imaging is often required to clarify indeterminate radiographic features. Magnetic resonance imaging (MRI) assists radiologists in evaluating lesions with indeterminate features as it has advantages in delineating tumorous tissues and bone marrow., Purpose: To evaluate the association factors of MRI for bony aggressiveness., Material and Methods: A retrospective analysis of 226 MRI examinations from patients diagnosed with bone tumors in a tertiary hospital during 2008-2018 was performed. All the MR images were interpreted by musculoskeletal radiologists without diagnostic information. The bony lesions were categorized into aggressive and non-aggressive groups using tumor margin, cortical changes, periosteal reaction, joint extension, extraosseous soft tissue involvement, tumor homogeneity, and enhancement pattern from the MR images. Univariable and multivariable analysis were applied for each feature on the MRI scans. In addition, sensitivity and specificity were calculated for MRI diagnoses of aggressive bone lesions., Results: In total, 180 aggressive and 46 non-aggressive bone lesions were examined on MRI. The sensitivity and specificity of MRI for differentiating between aggressive and non-aggressive bone lesions were 98.89% and 50%, respectively. Ill-defined margin, cortical break, cortical signal changes, sunburst and Codman's triangle periosteal reaction, joint extension, and tumoral and heterogeneous enhancement could be predictive signs for aggressive bone lesions., Conclusion: MRI can be a valuable tool to assist in distinguishing aggressive from non-aggressive bone lesions. In cases of indeterminate radiographic features, MRI could be used as an additional imaging to improve diagnostic accuracy and could reduce unnecessary invasive procedures.

Objectives: Musculoskeletal pain, one of the most common issues faced by older adults, has multidimensional effects including an increased risk of malnutrition. Therefore, this study aimed to investigate the association between pain interference and nutritional status in older adults with chronic musculoskeletal pain., Methods: In this cross-sectional study, data were collected from older adults (age: >60 years) using the brief pain inventory and mini nutritional assessment questionnaire. The correlation between pain interference, pain severity, and nutritional status was assessed using the chi-square test and Spearman's rank correlation. Multiple logistic regression analysis was used to analyze the variables associated with abnormal nutrition status., Results: Overall 241 older adults were recruited in the study. The median (IQR) age of the participants was 70 (11) years, pain severity subscale was 4.2 (1.8), and pain interference subscale was 3.3 (3.1). Abnormal nutritional status was positively correlated with pain interference (Odds ratio [OR]: 1.26; 95% confidence interval [CI]: 1.08-1.48; P  = .004), pain severity (OR: 1.25; 95% CI: 1.02-1.53; P  = .034), age (OR 1.06; 95% CI: 1.01-1.11, P  = .011), and hypertension (OR = 2.17; 95% CI: 1.11-4.26; P  = .024)., Conclusions: This study reports a strong correlation between pain interference and nutritional status. Therefore, pain interference can be a useful pain assessment tool to indicate risk of abnormal nutritional status in older adults. In addition, related factors, including age, underweight, and hypertension, were associated with a higher risk of malnutrition.

We prove a factorization formula for the point-to-point partition function associated with a model of directed polymers on the space-time lattice Z d + 1 . The polymers are subject to a random potential induced by independent identically distributed random variables and we consider the regime of weak disorder, where polymers behave diffusively. We show that when writing the quotient of the point-to-point partition function and the transition probability for the underlying random walk as the product of two point-to-line partition functions plus an error term, then, for large time intervals [0,  t ], the error term is small uniformly over starting points x and endpoints y in the sub-ballistic regime ‖ x - y ‖ ≤ t σ , where σ < 1 can be arbitrarily close to 1. This extends a result of Sinai, who proved smallness of the error term in the diffusive regime ‖ x - y ‖ ≤ t 1 / 2 . We also derive asymptotics for spatial and temporal correlations of the field of limiting partition functions., (© The Author(s) 2023.)

Background: The flipped classroom (FC) is a well-known active learning module that activates the prior knowledge of students and promotes their cognitive skills during in-class activities. However, most on-site teaching during the COVID-19 pandemic had to be conducted online. The FC in our rehabilitation medicine clerkship curriculum was also shifted to online asynchronous lectures (OLs), without real-time interactions. There is no previous comparison of effectiveness between these two methods. Therefore, this study aimed to compare learning outcomes and student satisfaction in both FC and OL models., Methods: The study design was a historically controlled study. A physical modality was chosen for the content. The FC group (n = 233), in the academic years 2018 and 2019, was assigned to perform a pre-class activity consisting of reading study materials. Thereafter, the in-class activity comprised a small-group case-based discussion. The OL group (n = 240) in the academic years 2020 and 2021 followed an online model during the COVID-19 lockdown. They were also asked to read the online materials and then watch a self-paced recorded lecture video on Learning Management Systems. The learning outcomes, including their multiple-choice questions (MCQs) scores, final exam scores, grade points, and letter grades, were evaluated. Their overall course satisfaction ratings were also collected., Results: The OL group had an overall higher MCQ score for the physical modality portion than the FC group (p = 0.047). The median (lower quartile, upper quartile) of the total 50-MCQ scores were 34 (31, 37) in the OL group and 33 (29, 36) in the FC group (p = 0.007). The median final exam scores of the OL and FC groups were 69.5 and 68.3, respectively (p = 0.026). The median grade points and the letter grades were not significantly different between the groups. The proportions of satisfaction were significantly higher in the FC group than in the OL group., Conclusions: The OL group revealed significantly higher learning outcomes than the FC group. However, the FC group showed more satisfaction with interactivity than the OL group. The authors are of the view that a combination of both FC and OL methods will likely result in better outcomes., (© 2022. The Author(s).)

Background: Topical tranexamic acid (TXA) has been widely used to reduce postoperative blood loss following total knee replacement (TKA). This study aimed to evaluate the effect of combined intramedullary, periarticular injection, and intraarticular TXA application in patients who underwent TKA as compared to those who did not., Methods: This was a retrospective case-matched study of 111 patients. We evaluated the transfusion rate and postoperative drainage of 56 patients who underwent TKA using combined topical tranexamic acid application (directly pushed into the femoral intramedullary canal and tibia base, with periarticular soft tissue injection and injected into the knee cavity via a drain tube) and the control group of 55 patients., Results: In the control and TXA groups, 7.14% and 1.81% of the patients received blood transfusions, respectively ( p =0.176). The closed-suction drainage output at 0-8 h and total drainage output were significantly lower in the TXA group than those in the control group ( p < 0.001)., Conclusion: Application of topical TXA with the combined method (intramedullary, periarticular injection, and intraarticular) in TKA decreases postoperative suction drainage and may reduce the need for postoperative blood transfusion., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2022 Theerawit Hongnaparak et al.)

Background: For large bone defects, after curettage of aggressive bone tumors; such as giant-cell tumors, cementation with supplement internal fixation was used to prevent subsequent collapse of the cement-bone constructs. The purpose of this study is to compare the pull-out strength of cement augmented screws between inserting screws in the working phase or hard phase of bone cement., Hypothesis: Timing at which completed screw insertion takes place affecting the pull-out strength of cement augmented screws., Methods: Pull-out strength was compared between screws; inserted within the working phases of cement, and after the cement was hardened in high viscos cement blocks. Each group consists of 10 cortex screws, 10 cancellous screws and 10 locking screws. The pull-out strength test was followed using the instructions of ASTM F543-13e1 Standard Specification and Test Methods, for Metallic Medical Bone Screws., Results: Screws that were inserted in the working phases of cement had significantly higher pull-out strength, than those inserted in hard cement (p=0.021). The pull-out strength was statistically significant in difference among the types of screws (p<0.001), with locking screws having the highest pull-out strength. Furthermore, the pull-out strength of locking screws revealed no significant difference when either; inserted during the working or hardened phases of bone cement., Conclusion: Insertion of screws during the working periods of PMMA cement had higher pull out strength compared to the hard phase of cement. Hence, we recommend performing internal fixation before cementation after curettage of aggressive bone tumors. However, if the surgeon prefers to pack the cement first, for the benefit of avoiding residual bone defects, we suggest using a locking plate system to achieve comparable pull-out strength., Level of Evidence: In-vitro study., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Purpose: To evaluate clot size and stenotic degree on conventional computed tomographic pulmonary angiography (CTPA) with perfusion defect., Material and Methods: Fifty-two pulmonary embolism (PE) patients with 144 PE locations underwent dual-energy CTPA with an iodine distribution map. Each PE location was rated as to whether there was a perfusion defect. Clot size, stenotic degree, and other associated PE findings were evaluated. These findings were then correlated with whether the perfusion defect was present., Results: There were no associations between demographics, clinical characteristics, anatomical data, and perfusion defect. The median iodine concentration ratio was 0.11. Imaging interpretation by 2 thoracic radiologists had excellent agreement. The clot size and stenotic degree in PE were significant predictors of perfusion defect on conventional CTPA. Lesions with higher degrees of stenosis had higher percentages of perfusion defect. The generalized estimating equation (GEE) logistic regression confirmed that clot size and stenotic degree could predict PE perfusion defects on conventional CTPA., Conclusions: The 2 significant predictors of perfusion defect were occluded vessels in both small and large branches together, or complete occlusion of the pulmonary artery., Competing Interests: The authors declare no conflict of interest., (© Pol J Radiol 2022.)

Introduction: Tranexamic acid is widely used for patients undergoing total knee arthroplasty (TKA). However, the duration of systemic tranexamic acid (TXA) administration varies in many reports. Hence, this study aims to compare blood loss between a single intravenous (IV) TXA dose, and one dose of IV TXA combined with oral TXA, during 48-hour postoperative care in primary TKA., Methods: Ninety-four patients with primary osteoarthritis, who underwent primary TKA, were randomized into two groups. The first group consisted of 47 patients and received a dose of 750 mg IV TXA and 750 mg oral TXA postoperatively at 8-hour intervals for 48 hours. In the second group, 47 patients received a single dose of IV TXA and a placebo at the same intervals for the same time duration. Hemoglobin (Hb) was measured at 4, 24 and 72 hours after operation., Results: The mean total blood loss were not different between the two groups (p=0.37). There was no difference in total Hb reduction or closed suction drainage outputs (p=0.9 and 0.07, respectively)., Conclusion: The extended use of oral TXA for 48-hour postoperative care did not decrease the total blood loss following TKA compared with a single dose of IV TXA. Level Of Evidence I; High quality randomized trial ., Competing Interests: All authors declare no potential conflict of interest related to this article.

We consider large-scale point fields which naturally appear in the context of the Kardar-Parisi-Zhang (KPZ) phenomenon. Such point fields are geometrical objects formed by points of mass concentration, and by shocks separating the sources of these points. We introduce similarly defined point fields for processes of coalescing fractional Brownian motions (cfBMs). The case of the Hurst index 2/3 is of particular interest for us since, in this case, the power law of the density decay is the same as that in the KPZ phenomenon. In this paper, we present strong numerical evidence that statistical properties of points fields in these two different settings are very similar. We also discuss theoretical arguments in support of the conjecture that they are exactly the same in the large-time limit. This would indicate that two objects may, in fact, belong to the same universality class.

In this paper, we study several problems related to the theory of randomly forced Burgers equation. Our numerical analysis indicates that despite the localization effects the quenched variance of the endpoint distribution for directed polymers in the strong disorder regime grows as the polymer length [Formula: see text]. We also present numerical results in support of the 'one force-one solution' principle. This article is part of the theme issue 'Scaling the turbulence edifice (part 2)'.

Background: Gastrointestinal perforations are a frequent cause of acute abdominal symptomatology for patients in the emergency department. The aim of this study was to investigate the findings of multidetector-row computed tomography of gastrointestinal perforations and analyze the impact of any imaging signs on the presurgical identification of the perforation site. Methods: We retrospectively reviewed emergency MDCT findings of 93 patients submitted to surgery for gastrointestinal perforation at two different institutions. Two radiologists separately reviewed the emergency MDCT examinations performed on each patient, before and after knowing the surgical diagnosis of the perforation site. A list of findings was considered. Positive predictive values were estimated for each finding with respect to each perforation site, and correspondence analysis (CA) was used to investigate the relationship between the findings and each of the perforation types. Results: We did not find inframesocolic free air in sigmoid colorectal perforations, and in rare cases, only supramesocolic free fluid in gastroduodenal perforations was found. A high PPV of perivisceral fat stranding due to colonic perforation and general distension of upstream loops and collapse of downstream loops were evident in most patients. Conclusions: Our data could offer additional information on the perforation site in the case of doubtful findings to support surgeons, especially in planning a laparoscopic approach.

Objective  Tranexamic acid (TXA) is an antifibrinolytic that is widely used for decreasing blood loss and blood transfusion rates in total hip arthroplasty. However, there is limited evidence of topical TXA usage in hip hemiarthroplasty for femoral neck fractures. The present study aimed to evaluate the effects of topical TXA on blood loss and on blood transfusions in femoral neck fracture patients who underwent cemented bipolar hemiarthroplasty. Methods  Twenty-six patients with femoral neck fractures who were scheduled for bipolar cemented arthroplasty were randomized into two groups. The first group of 12 patients received topical TXA during their operation, whereas 14 patients in the second group received a placebo. Hematocrit was measured at 6 and 24 hours postoperatively. Blood transfusions and postoperative complications were also recorded. Results  Total blood loss was not different between the TXA group and the control group (TXA group: 459.48 ± 456.32 ml, and control group: 732.98 ± 474.02 ml; p  = 0.14). However, there were no patients within the TXA group who required a blood transfusion, while there were 4 patients in the control group who received allogenic blood transfusions ( p  = 0.044). There were no postoperative complications, such as wound complication, venous thromboembolism, or cardiovascular complications within either group. Conclusion  Topical TXA could not decrease total blood loss but was able to reduce transfusion rates in patients who underwent cemented bipolar hip hemiarthroplasty in femoral neck fractures. Further studies in doses of topical TXA in a larger sample size would be beneficial. Level of Evidence  II., Competing Interests: Conflito de Interesses Os autores declaram não haver conflito de interesses., (Sociedade Brasileira de Ortopedia e Traumatologia. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. ( https://creativecommons.org/licenses/by-nc-nd/4.0/ ).)