Degree Of Closure Research Articles

Closure of large mucosal defects for prevention of strictures after duodenal endoscopic submucosal dissection (with video)

Although lesions occupying a large circumference are associated with the risk of post-endoscopic submucosal dissection (ESD) strictures, the corresponding data for duodenal lesions are unknown. We aimed to analyze the incidence of post-ESD strictures after wide-field duodenal ESD. In this retrospective study of duodenal lesions treated with ESD between July 2010 and August 2021, we included lesions that resulted in mucosal defects occupying more than half of the circumference and excluded lesions located in bulbs and involving Vater's papilla. We analyzed the incidence rates of stricture and luminal narrowing, in addition to bleeding and perforation as the outcomes in this study. Stricture was defined as the inability of the endoscope to pass through the lumen. A single endoscopist reviewed all endoscopic images and judged the degree of luminal narrowing. Eighty lesions were included, of which 2 involved mucosal defects occupying more than 90% of the circumference. The wound was closed, at least partially, in 90% in all lesions and in 86% of lesions with a mucosal defect occupying more than 75% of the circumference. None of the lesions caused delayed perforation and stricture, whereas 2 lesions caused delayed bleeding. Only 6 lesions caused luminal narrowing. When examined by the degree of closure, the rate of luminal narrowing increased with complete closure, incomplete closure, and nonclosure (4.9%, 9.1%, and 25.0%, respectively). Suturing may prevent post-ESD bleeding and perforation as well as stricture formation in cases of duodenal tumors, with mucosal defects occupying a large circumference.

EXPERIMENTALL SUBSTANTIATION FOR APPLYING ACTOVEGIN IN COMBINATION WITH OSTEOPLASTIC MATERIALS IN MANDIBULAR BONE TISSUE REGENERATION

The aim of the study is to perform a comparative assessment of the effectiveness of applying various osteoplastic materials in combination with Actovegin in stimulating bone tissue regeneration. Materials and methods. In order to study the osteoplastic properties and determine the peculiarities of the course of reparative processes, as well as to substantiate the treatment method we elaborated, in vivo experimental studies were carried out on 36 male rabbits weighing from 1.5 to 2.5 kg at the Scientific Research Centre of the Azerbaijan Medical University. The animals were kept in a vivarium under standard conditions on the standard diet and were under the study for 60 days since the inclusion in the experimental model. Having been included into the study, the animals were randomly divided into 3 groups of 12 rabbits in each: in the animals of Group I, the main group, individual bone defects were formed on both sides of the lower jaw; the subgroup A included animals, whose artificially formed defects on one side of the jaw were closed with an allograft and platelet-rich fibrin exudate (PRF), subgroup B included animals with the same modelled damage, who received the treatment mentioned above and additional Actovegin; Group II was a comparison group, received a mixture of autogenous bone, PRF and Actovegin injected into jaw defects; Group III was the control group, which received PRF and Actovegin injected intravenously in a dose of 1 mg daily for 2 weeks. Results. Neutrophilic infiltration was found at the maximum level (1.33±1.07) in the area of the mandibular bone defect in subgroup A of I group, where only the allograft was used without additional Actovegin. In group III, who received the combination with PRF and intravenous administration of Actovegin, the average rate of lymphocytic infiltration by the end of the experiment was 1.75±0.75 that correlates with the severity of the degree of bone defect closure. Vascularization or blood supply to pre-damaged bone tissue, in particular to the residual area of the bone defect, was detected at the lowest level in the group of animals, who did not receive Actovegin during the implantation of osteotropic material into the defect site (1.25±0.45). Vascularization, which impacts the bone tissue regeneration, was the most intensive when applying Actovegin (1.91±0.66). In the samples obtained in group II and subgroup B, more capillaries and, accordingly, a high density of the capillary network (p<0.01) were detected in the area of the bone defect more often than in other groups of animals. Conclusion. Inflammatory changes (neutrophilic, lymphocytic and plasma cell infiltration) in the residual zone, which is part of the bone defect, were less pronounced in the group of topical application of autologous bone and Actovegin. At the same time, it was noted that the amount of eosinophilic infiltration and granulomatous reactions were more intense when using an allograft.

Clinical report of hoding cricoarytenoid joint reduction with visual laryngoscope under intravenous anesthesia

Objective: To investigate the reduction effect of hoding cricoarytenoid joint reduction with visual laryngoscope under intravenous anesthesia. Methods: The therapeutic effects of 40 patients with arytenoid dislocation(AD)treated by closed reduction in the single center from January 2020 to September 2021 were retrospectively analyzed, including 21 males and 19 females, median age 48 years. The etiology, symptoms, preoperative evaluation methods, reduction mode, reduction times, and the recovery of arytenoid cartilage movement and sound after reduction were evaluated and analyzed. Results: All patients had obvious hoarseness and breath sound before treatment. Under stroboscopic laryngoscope or electronic nasopharyngoscope, different degrees of vocal cord movement disorder and poor glottic closure can be seen. There were 28 cases of left dislocation, 9 cases of right dislocation and 3 cases of bilateral dislocation. The etiology of dislocation of cricoarytenoid joint: 25 cases (62.5%) of tracheal intubation under general anesthesia were the most common causes, was as follows by laryngeal trauma, gastroscopy, cough, vomiting and so on. Among them, 28 cases of reduction were initially diagnosed in our department, and 12 cases were diagnosed later after failure of reduction treatment. Of the 40 patients, 6 underwent reduction 24 hours after dislocation; 18 cases from 3 days to 1 month; 7 cases from 1 to 3 months; 6 cases were reset in 3~6 months; Over 6 months in 3 cases. After one reduction, 10 cases (10/40, 25%) recovered normal pronunciation, 14 cases (14/40, 35%) recovered normal pronunciation after two reduction, 10 cases (10/40, 25%) recovered normal pronunciation after three times, 2 cases (2/40, 5%) recovered normal pronunciation after four times, and 1 case (2.5%) recovered normal pronunciation after five times. Thin slice CT scan of larynx and cricoarytenoid joint reconstruction showed the types of AD: subluxation in 37 cases (92.5%) and total dislocation in 3 cases; 28 cases of left dislocation, 9 cases of right dislocation and 3 cases of bilateral dislocation; 29 cases (72.5%) had posterior dislocation and 11 cases (27.5%) had anterior dislocation. All patients were treated by intravenous anesthesia with arytenoid cartilage clamped by cricoarytenoid joint reduction forceps under visual laryngoscope. The curative effect was evaluated by stroboscopic laryngoscope and/or voice analysis at 1-2 weeks after operation. The vocal cord movement returned to normal and the pronunciation was good in 37 cases (92.5%). Conclusions: Hoding cricoarytenoid joint reduction with the vision laryngoscope under intravenous anesthesia is easy to operate and the reduction effect is more stable. It is a effective method for AD.

Temporal Variation in Abundance and Distribution of Butterflies in a Southern Nigerian National Park

Aims: The aim of this study was to determine the butterfly diversity in Okomu National Park, Nigeria in order to make available information on butterfly species in this protected areas. Background: Butterflies are a taxonomically important group for predicting the health of the environment. Objective: In order to establish butterfly abundance and distribution in Okomu National Park, a temporal variation study was conducted for a period of twenty-four months (July 2012 to June 2014). Methods: Eight transects (Disturbed habitat (DIS), Forest Edge/Plantation (FE/P), Moderately Open Forest (MOF), Forest Along Road/Moist Patches (FAR/MP), Riparian Habitat (RIP), Closed Canopy (CC), Shrub (SHR) and Grassland (GRA) were mapped out from the four ranges (Igwonwan, Arakhuan, Julius Creek and Babui) from visual level of disturbance and degree of canopy closure for transect walk, butterfly net and baited trap methods of butterfly sampling. Environmental variables (temperature, relative humidity, and rainfall) were concurrently sampled with butterflies. Results: A total of 143 species and 6,310 individuals of butterflies were obtained from the families; Nymphalidae, Papilionidae, Pieridae, Lycaenidae, and Hesperiidae. Nymphalid (3103: 49.2%) and Pieridae (2269: 36.0%) predominated and Hesperiidae was recorded low (8: 0.1%). Significant differences were observed in the abundance of butterflies in the transects (p< 0.05). Rainfall was positively correlated with butterfly abundance. Butterfly abundance was higher in rainy season compared to dry season except in RIP where a reverse trend was observed. Abundance was higher in FAR/MP (1633: 25.9%) and MOF (1251: 19.8%) compared to other transects, and was lowest in SHR (295: 4.7%). Conclusion: It can be concluded that butterfly in Okomu forest is abundant and stable, and as such continuous effort is required to conserve butterfly flora and fauna in this park.

Modes of Incorporation: The Inclusion of Migrant Academics in the UK

This article examines the internationalisation of professions in a qualitative study of migrant academics, drawing on social closure theory to understand how professions respond to the growing numbers of migrants. While studies of closure in professions tend to focus on forms of exclusion based on ascribed characteristics, this article is concerned with how professions include migrants in their ranks. Analysis of interviews with 62 foreign-born academics working in the UK reveals differences in degree of closure towards migrant academics, indicating that inclusion and exclusion are not binary opposites. The article captures degrees of closure in a novel concept – ‘modes of incorporation’ – identifying three inclusion patterns: integration, subordination and marginalisation. ‘Modes of incorporation’ extends closure theory by showing how inclusion is controlled and designed to preserve the status quo, thereby restricting internationalisation.

ADTIDO: Detecting the Tired Deck Officer with Fusion Feature Methods.

The incidence of maritime accidents can be significantly reduced by identifying the deck officer’s fatigue levels. The development of car driver fatigue detectors has employing electroencephalogram (EEG)-based technologies in recent years and made it possible to swiftly and accurately determine the level of a driver’s fatigue. However, individual variability and the sensitivity of EEG signals reduce the detection precision. Recently, another type of video-based technology for detecting driver fatigue by recording changes in the drivers’ eye characteristics has also been explored. In order to improve the classification performance of EEG-based approaches, this paper introduces the ADTIDO (Automatic Detect the TIred Deck Officers) algorithm, an EEG-based classification method of deck officers’ fatigue level, which combines a video-based approach to record the officer’s eye closure time for each time window. This paper uses a Discrete Wavelet Transformer (DWT) and decomposes the EEG signals into six sub-signals, from which we extract various EEG-based features, e.g., MAV, SD, and RMS. Unlike the traditional video-based method of calculating the Eyelid Closure Degree (ECD), this paper then obtains the ECD values from the EEG signals. The ECD-EEG fusion features are then created and used as the inputs for a classifier by combining the ECD and EEG feature sets. In addition, the present work develops the definition of “fatigue” at the individual level based on the real-time operational reaction time of the deck officer. To verify the efficacy of this research, the authors conducted their trials by using the EEG signals gathered from 21 subjects. It was found that Bidirectional Gated Recurrent Unit (Bi-GRU) networks outperform other classifiers, reaching a classification accuracy of 90.19 percent, 1.89 percent greater than that of only using EEG features as inputs. By combining the ADTIDO channel findings, the classification accuracy of deck officers’ fatigue levels finally reaches 95.74 percent.

SP7.11 Preliminary results from the TACKoMesh RCT; comparing the patient experience of pain following elective laparoscopic incisional hernia repair with ‘Protack™ versus Reliatack™’, IPOM and sutured fascial closure

AimsProvide a report on all patients who underwent laparoscopic incisional hernia repair as part of the TACKoMesh RCT prior to unblinding of treatment arms.MethodsTrial recruitment was for primary incisional hernia with a defect diameter of 3–10cm. 63 patients (target 74–136) were operated on prior to the outbreak of COVID-19. Post-operative pain is the primary trial outcome.Surgery was performed with spiral-tack mesh-fixation devices (Protack™ (permanent) or Reliatack™ (absorbable)), Symbotex™ IPOM mesh, and sutured fascial closure using extracorporeal knot ties.Data was collected on trial forms and lifestyle questionnaires (SF-36 and CCS). All data were explored and described in RStudio v1.4.1106.ResultsPatients were aged 36–80 and 57.1% male. Mean preoperative BMI was 30.91.Mean operating time was 81minutes. In 20.6% patients multiple hernia defects were identified. A good degree of fascial closure was achieved in all patients using a median 3 knots.Median mesh-fixation time was 286seconds and a mean of 25 tacks/patient were used. Median length of hospital stay was 3.5days.Patients were asked “Please indicate on this scale [VAS 0–10] the pain that you currently experience from your incisional hernia during activity?”. Median responses for Day0/pre-op, Day1, Day6, Day30 and Day365 were 4.5, 8.0, 6.0, 3.0 and 1.5 respectively.At one year, 11% patients had experienced hernia recurrence and 52% a post-operative seroma.ConclusionsTarget recruitment was not possible owing to COVID-19. This technique has comparable recurrence rates. Reported pain increases post-operatively but is reduced at post-operative day30 and day365.

Verifying Efficacy of Self-Inhalation Training for Velopharyngeal Dysfunction

Velopharyngeal closure in healthy adults during different tasksObjective: Velopharyngeal dysfunction causes not only resonance problems (so-called “hypernasality”) but also dysphagia, particularly in the elderly. In our previous study, we developed a new inhaling training method to objectively improve velopharyngeal function using the measurement of peak inspiratory flow (PIF) rate, which was effective in all patients. In this study, we clarify the degree of velopharyngeal closure to determine the efficacy of our training to improve the closure mechanism. Methods: Three healthy volunteers performed tasks in a magnetic resonance imaging (MRI) gantry in the supine position. To confirm velopharyngeal function, volunteers were first asked to distinguish the difference in the velum position between the production of a nonnasal (sustained phonation /shi:/) and a nasal (sustained phonation /n:/) sound. They were then asked to inhale forcefully through the mouth from an empty 500-mL plastic bottle. For comparison, volunteers performed exhaling forcefully, then inhaling and exhaling softly, through a straw. Each task was performed for 30 s, and the MRI images were obtained in sagittal sections. Results: Inhaling forcefully from an empty plastic bottle created the strongest velopharyngeal closure between the posterior surface of the velum (soft palate) and the posterior pharyngeal wall in all volunteers. Conclusion: The results of our MRI study supported our training method. Using inhalation through a PIF meter or from a plastic bottle to create resistance strengthens particularly the levator veli palatini muscle for velopharyngeal closure, which may be useful in patients with other acquired velopharyngeal dysfunctions including physiological aging. Also, anyone anywhere can train with plastic bottles.

TAŞKENT BÖLGESİNİN DAĞLIK ARAZİSİNDE BULUNAN GÖKTÜRK KAĞANLIĞI’NA AİT SÜNGEK MEZAR KURGANLARI HAKKINDA YAPILAN ÇALIŞMALAR

Makalede Özbekistan’ın Taşkent vilayetine bağlı Çarvak su barajı kıyılarında bulunan Batı Göktürk Kağanlığı dönemine ait Süngek mezarında sürdürülen arekolojik kazı çalışmaları ve burada elde edilen bilimsel sonuçlardan bahsedilmektedir. 2019 yılından beri gerçekleştirilmekte olan arkeolojik kazılarda elde edilen buluntular diğer iskan yerlerindeki buluntular ve ölü gömme gelenekleriyle karşilaştirilmiş ve genel benzerliklerin yanı sıra adı geçen mezarıdakı kendine özgülükler tespit edilmiştir. Adı geçen mezarlıkta insan ve hayvan kemikleriyle birlikte çeşitli biçimlerdeki seramik kaplar, demir yapımı çeşitli eşyalar ve iş aletleri bulunmuştur. Mezarlardaki insan kemikleri, özellikle insan kafatası üzerinde alınan ölçüler, bazı insan kemiklerinin bulundurulduğu yön ve tas kemiğinin durumu, cins ayırımına dikkat edilmiştir. Merhumların yaşını belirtirken de onların baş kemiklerdeki yarıkların kapanış derecesi, dişlerin yıpranması ve kemik boğumlarının oluşum sahfaları göz önünde bulundurulmuştur. Süngek’te elde edilen buluntular, Göktürk Kağanlığı dönemine ait yerel ölü gömme gelenekleri ve yerleşkenin bulunduğu bölge ahalisiniin iktisadî ve sosyal yaşam tarzı üzerine durulmaktadır. Süngek mezarının sakinleri yerel kültür elemanlarını kendinde barındıran hayvancılıkla uğraşan göçebe toplumların Eski Türk dönemine özgü yadıgarlıklar grubuna dahildirler. Mezarnın sahipleri komşu bölgeler: Çırçık – Ahengeran vadisi, Güney Kazakistan, Talas, Farğana ve Yedisu bölgelerinin sakinleriyle sıkı ilişkilerde bulunduğu anlaşılmaktadır. Süngek mezar kurganlarından elde edilen yeni buluntular, Orta Asya topraklarının miladi birinci binyıllığı ortalarında yaşayan toplumların kültürü ve tarihininin oldukça güncel ve aynı zamanda tartışmalı olan Kavunçı kültürünün historiografisi, Çırçık vadisi yukarı havzasının Erken orta çağlar döneminin etnik yapısı, hayvancı göçebe toplulukların ölü gömme gelenekleri ve dinî dünya bakış açıları gibi meselelerin incelenmesi için kaynak görevini yapacağı anlaşılmaktadır. Adı geçen tarihlerde Avrasya bozkırlarında olup biten migrasyon süreçlerinin incelenmesi ve daha anlaşılır olması yüzünden Süngek mezarı ve benzerlerinin ileride daha derin incelnemesi gerekmektedir.

Spheno-Occipital Synchondrosis Fusion Degree as an Age Estimation Tool: A Cone-Beam Computed Tomography Study

Background: Considering the late ossification potential of spheno-occipital synchondrosis (SOS), it can be used as a tool to estimate age in adolescents. The time of SOS fusion is known to vary in different populations. Objectives: This study aimed to assess the degree of SOS fusion in Iranian individuals, using cone-beam computed tomography (CBCT) scan. Patients and Methods: The CBCT images of 240 patients (126 females and 114 males), aged 6 - 25 years, were assessed regarding the degree of SOS fusion, based on a four-stage scoring system. Spearman’s correlation coefficient test and regression analysis were performed to assess the correlation between age and fusion stage. Mann-Whitney test was also applied to determine differences between males and females. Besides, Kruskal-Wallis test was used to assess differences in the median values. Results: The SOS was completely open at the mean age of 7.63 years in females and 8.85 years in males. The mean age of partially fused SOS (stage 1) was 8 years in females and 10 years in males. Besides, the mean age of completely fused SOS (stage 3) was 12 years in females and 16 years in males. The results of Spearman’s correlation coefficient test showed a significant positive relationship between age and the degree of SOS fusion in males and females (rs = 0.783, P < 0.001 in females and rs = 0.911, P < 0.001 in males). Conclusion: The SOS closure degree can be applied for age estimation in the Iranian population. This study presented a method which is highly accurate for age estimation.

Assesment of Root Apices Closureof Permanent Incisors and First Molars in Digital Orthopantomographs: A Pilot Study From Pakistan

Objective:The purpose of the current study is to assess the degree of closure of the root apices of primary molars and permanent incisors in young children. Study Design:Retrospective study Place and Duration: This study was carried out at Department of Oral Biology, Sardar Begum Dental College, Peshawar from January, 2022 to July 2022. Methods: There were 130 patients of both genders with ages 4-16 years were presented. After obtaining informed written consent, the enrolled cases' detailed demographics, including age, sex, body mass, and locale, were computed. Digital orthopantomographs of all the patients were taken. Chi square test was used to assess differences among closure of root apices of permanent incisors and first molars among all cases. SPSS 22.0 was used to analyze all data. Results:Among 130 included cases, 80 (61.5%) were females and the rest were males 50 (38.5%).Mean age of the cases were 12.6±4.72 years. 85 (65.4%) cases had body mass index <18 kg/m2 and 45 (34.6%) patients had BMI >18kg/m2. There were 76 (58.5%) cases had urban and 54 (41.5%) patients had rural residency. Permanent incisors were 82 (63.1%) and first molars were 48 (36.9%). At age between 5-9 years frequency of closed root apices of mandibular central incisors was 50 (60.9%) and closed maxillary first molars were 22 (51.2%). At age 10-15 years number of closed root apices of central incisors were 65 (79.3%) and closed root apices of first molars were 30 (62.5%) with p value <0.003. Conclusion:In this study, we came to the conclusion that the majority of root apices of permanent incisors and first molars in children in the studied sample close early compared to earlier reports, which is consistent with the pattern of emergence of permanent teeth previously reported in children. Keywords:Root Apices, First Molars, Permanent Incisors, Children

Effects of Grape Downy Mildew on Photosynthesis of ‘Red Globe’ Grape Leaves under High Temperature Stress

ABSTRACT Grape downy mildew is a major grape disease that typically occurs when grape leaves are subjected to high temperature. In this study, downy mildew incidence in ‘Red Globe’ grape was investigated. To clarify the effects of grape downy mildew on grape leaves under high-temperature stress. Grape downy mildew infestation and high-temperature treatment alone or combinations were applied to ‘Red Globe’ grape. The gas exchange and chlorophyll fluorescence parameters of grape leaves were measured. The results showed that logistic growth period of grape downy mildew in the Jinzhong, China was from July 20 to August 10. After the combined stress of high temperature and grape downy mildew, photosynthetic rate (Pn), stomatal conductance (G s), intercellular carbon dioxide concentration (C i), maximum photochemical efficiency(Fv/Fm), actual photochemical efficiency(ΦPSII), and performance index on absorption basis (PIABS ) of grape leaves were all decreased more than the sum of those indexes under the two stresses individually. At 28°C, the damage of downy mildew had no significant effect on the degree of photosystem closure of leaves, but it was significantly increased with the combined stresses. The electron transfer efficiency from photosystem II to photosystem I was decreased significantly under the combined stresses. Under 38°C high-temperature stress, the energy dissipated per active reaction center of the leaves affected by grape downy mildew was significantly increased. High temperature aggravated adverse effects of downy mildew on the structure and function of photosystem II (PSII) of grape leaves and then further exacerbated reduction of photosynthesis caused by heat stress.

Experimental Implementation of Energy Closure Analysis for Reduced Order Modeling

Abstract Reduced order models (ROMs) provide an efficient, kinematically condensed representation of computationally expensive high-dimensional dynamical systems; however, their accuracy depends crucially on the accurate estimation of their dimension. We here demonstrate how the energy closure criterion, developed in our prior work, can be experimentally implemented to accurately estimate the dimension of ROMs obtained using the proper orthogonal decomposition (POD). We examine the effect of using discrete data with and without measurement noise, as will typically be gathered in an experiment or numerical simulation, on estimating the degree of energy closure on a candidate reduced subspace. To this end, we used a periodically kicked Euler–Bernoulli beam with Rayleigh damping as the model system and studied ROMs obtained by applying POD to discrete displacement field data obtained from simulated numerical experiments. An improved method for quantifying the degree of energy closure is presented: the convergence of energy input to or dissipated from the system is obtained as a function of the subspace dimension, and the dimension capturing a predefined percentage of either energy is selected as the ROM dimension. This method was found to be more robust to data discretization error and measurement noise. The data-processing necessary for the experimental application of energy closure analysis is discussed in detail. We show how ROMs formulated from the simulated data using our approach accurately capture the dynamics of the beam for different sets of parameter values.

Changes and closure grades of the laryngeal vestibule in different positions after anesthesia induction.

The aim of this study was to observe changes in the laryngeal vestibule under head extension or in neutral position with or without the chin lifted after anesthesia induction. After anesthesia induction, a flexible bronchoscope was used to observe the status of the laryngeal vestibule under four positions. Then, the degree of laryngeal vestibule closure was graded. The grading scores and the incidence of severe closure under these four positions were compared. The factors that may be related to the severe closure and potential contributions of head extension and chin lifting were also analyzed. When laryngeal mask was applied, the change in the laryngeal vestibule state was observed through the laryngeal mask after placement. The closure scores of the laryngeal vestibule were significantly different among these four positions (P<0.001). The incidence of severe closure was highest in the neutral head position without the chin lifted. Regression analysis showed that age and snoring were associated with severe closure of the laryngeal vestibule. Both head extension and chin lifting could decrease the risk of severe closure of the laryngeal vestibule, and head extension was more important than chin lift. After laryngeal mask placement, the severely closed laryngeal vestibule can be further opened up to grades 1-2. The neutral position of the head after anesthesia induction may cause complete closure of the laryngeal vestibule. The best way to keep the laryngeal vestibule open is head extension with the chin lifted, while most the laryngeal vestibules will be severely closed in the neutral position without the chin lifted.

The influence of heterogeneous proppant pack on fracture closure and productivity

Even though hydraulic fracturing is a common and well adopted well stimulation method in petroleum industry, there are still open scientific questions in the area, mainly due to complexity of the phenomena involved in the process. In this paper, we particularly address the problem of fracture closure and productivity in situations, when proppant distribution inside the fracture is strongly heterogeneous. This can happen, for instance, during pulsed injection, in which a pulse of clean fluid is alternated with a pulse of slurry with proppant. Such a combination leads to Saffman–Taylor instability and, consequently, to spatially heterogeneous distribution of proppant. To address the problem, a coupled hydraulic fracturing and proppant transport model is utilized to simulate proppant placement in a fracture. After that, a three-dimensional finite element model is used to compute fracture closure and fluid inflow or productivity. Several numerical examples with various pumping schedules are presented to better understand the influence of proppant heterogeneity on fracture closure and the resulting production. In addition, to get insights about the observed behavior, an analytical model for fracture closure between two proppant pillars is presented. The model provides a single dimensionless parameter that quantifies the degree of fracture closure between the pillars of proppant. Numerical results are analyzed and discussed in relation to this dimensionless number.

Dual composite bioadhesives for wound closure applications: An in vitro and in vivo study

AbstractOver the years, new biomaterials have been introduced as an alternative to conventional wound closure methods. Compared with traditional methods including sutures and staples, bioadhesives are more convenient to use and less time‐consuming. Nevertheless, the application of topical skin adhesives such as Cyanoacrylates (CA) is limited, due to cytotoxicity. Hence, developing skin adhesives with strong adhesion to soft tissue in wet environment, controlled physical and mechanical properties, and excellent biocompatibility has been a significant challenge. In the current study, we developed a new bioadhesive based on the highly biocompatible natural polymers gelatin and alginate. In order to enhance the mechanical‐ physical properties and functionality, two types of fillers were loaded: hemostatic agent (kaolin or montmorillonite) and cellulose fibers. Our in‐vitro results show that the addition of the functional fillers increased the tensile strength and modulus of the bulk material, leading to higher sealing ability and higher bonding strength. In addition, the gelation time and swelling degree were significantly decreased and the viscosity increased with the incorporation of the filler, which enables better functioning. The in‐vivo model focused on using a porcine skin incision, demonstrated superior efficacy of these new bioadhesives compared to the control group. I.e., they resulted in rapid healing, less inflammation, and a higher degree of wound closure. In conclusion, our dual‐composite bioadhesives demonstrated promising potential for use in wound closure applications and may serve as a suitable alternative for conventional sutures. Their unique properties make them beneficial, especially for first medical care applications such as rescuing casualties.

Evolution Behavior and Closure Mechanism of Porosity in Large Billet during the Reduction Pretreatment

The reduction pretreatment process was proposed to be applied to large billets for the purpose of alleviating the center porosities and reducing the rolling ratio. This study focused on the evolution behavior and closure mechanism of porosity in a large billet during reduction pretreatment. The porosities were characterized by ultrasonic scanning and 3D reconstruction. The results showed that the porosities near the surface of the billet were firstly closed during the reduction pretreatment. The reduction began to effectively act on the center of the billet at the deformation of 0.16. When the reduction amount increased to 0.20–0.22, both the pore number and the porosity degree at the center of the billet were the smallest. As the deformation exceeded 0.25, the porosities gathered at the center of the billet, which may have caused larger defects. A numerical model for the reduction pretreatment was established to analyze the evolution behavior of porosity. The simulation results showed that the position with the maximum of strain moved toward the center of the billet as the reduction amount increased. At the position where the deformation was 0.20, the deformation would readily occur at the center, and the center strain was almost twice as much as the surface strain. The upper and lower surfaces of porosity were compressed to the center of the porosity in the thickness direction. The two ends of porosity were not stretched in the rolling direction. The closure index indicated that the deformation penetrated into the center would accelerate the deformation of porosity. The cross-sectional area of the porosity gradually decreased with the increase in the hydrostatic integration, which indicated that the hydrostatic integration could be used to assess the closure degree of porosity during the reduction pretreatment process. Both the closure index and the hydrostatic integration proved the effective role of the reduction pretreatment in the alleviation of porosity.

Comprehensive evaluation of velopharyngeal function in myasthenia gravis patients.

Hypernasality, which is a symptom of dysarthria, may be seen in patients with Myasthenia Gravis with bulbar symptoms. However, there is not enough evidence to show that these patients may have velopharyngeal dysfunction. This study investigates the features of velopharyngeal function in myasthenia gravis patients using objective and subjective measurement tools. Ten adult myasthenia gravis patients with bulbar symptoms and ten adult myasthenia gravis patients without bulbar symptoms were recruited for this study. Ten healthy subjects were also included as the control group. The nasalance scores of the participants were determined using a nasometer. The degree and pattern of velopharyngeal closure were scored using flexible nasoendoscopy during speech, blowing, dry swallowing, and food swallowing. Perceptual hypernasality was assessed. Velopharyngeal dysfunction was detected in 50% of the myasthenia gravis patients with bulbar symptoms. Velopharyngeal dysfunction was not seen in myasthenia gravis patients without bulbar symptoms. The degree of velopharyngeal closure in patients with bulbar symptoms differed depending on the tasks being performed. No significant difference in velopharyngeal closure patterns was observed between the groups (p < 0.05). Myasthenia gravis patients with bulbar involvement may have velopharyngeal dysfunction. It is important to conduct a comprehensive evaluation to assess all aspects of the velopharyngeal function.

Evaluating the Role of Middle Ear Risk Indices in Assessing Postoperative Outcome following Tympanoplasty Procedure

Introduction Tympanoplasty is the treatment of choice for patients suffering with Chronic Otitis Media (COM). Outcome of tympanoplasty depends on various factors like size and location of tympanic membrane perforation, ear ossicles, degree of otorrhea, cholesteatoma, smoking history, granulation tissue etc. Prediction of outcome of tympanoplasty procedure prior to surgery with respect to graft uptake and hearing improvement can serve as a crucial factor in decision making in resource limited nations. Hence, a study was conducted to evaluate the role of Middle Ear Risk Indices (MERI) in predicting the outcome among patients undergoing tympanoplasty procedure. Materials and Methods A prospective study at a tertiary care centre was conducted for a duration of 2 years among 60 patients with COM who underwent tympanoplasty. Results The mean age of patients was 25.32 ± 8.43 years with a male to female ratio of 3:2. Majority (78.46%) of the patients had Mild MERI score; 18.46% patients had moderate MERI score and 3.08% patients had severe MERI risk score. The difference in mean Air –Bone (AB) gap in the mild and moderate MERI groups’ pre and post operatively was found to be statistically highly significant (p&lt;0.001). Conclusion Lower MERI scores prior to surgery showed significantly better outcomes with respect to graft uptake, degree of AB gap closure and hearing improvement.

Chitosan/PVA Hetero-Composite Hydrogel Containing Antimicrobials, Perfluorocarbon Nanoemulsions, and Growth Factor-Loaded Nanoparticles as a Multifunctional Dressing for Diabetic Wound Healing: Synthesis, Characterization, and In Vitro/In Vivo Evaluation.

Diabetic foot ulcers remain one of the most difficult-to-treat complications of diabetes and may seriously threaten the life of patients since it frequently results in limb loss due to amputation, suggesting that an effective therapeutic strategy is still urgently needed. In this study, a chitosan-based heterogeneous composite hydrogel encapsulating perfluorocarbon emulsions, epidermal growth factor (EGF)-loaded chitosan nanoparticles, and polyhexamethylene biguanide (PHMB) named PEENPPCH was developed for diabetic wound healing. The PEENPPCH could sustainably release EGF and PHMB in an ion-rich environment to exert antibacterial effects and promote cell growth for wound repair. In addition, the PEENPPCH can provide anti-inflammatory effects functioned by its main constituent of chitosan. Moreover, the PEENPPCH can proactively offer oxygen delivery through the incorporation of perfluorocarbon and, therefore, is able to alleviate hypoxia conditions on diabetic wounds. These functionalities enabled a markedly enhanced wound healing efficacy on diabetic rats treated with the PEENPPCHs, including thorough re-epithelization, a reduced inflammatory response, faster collagen deposition, and advanced collagen maturation resulting in a 95% of wound closure degree after 15 days that was 12.6% (p < 0.05) higher than the value of the group treated with the commercial dressing HeraDerm. Given the aforementioned advantages, together with the known merits of hydrogels, the developed PEENPPCH is anticipated to be a feasible tool for clinical diabetic wound treatment.