Internal Lining Research Articles

Three-Layer Reconstruction of a Full-Thickness Nasal Alar Defect after Basal-Cell Carcinoma Removal

Restoring the integrity of the external nose presents a complex surgical challenge due to its three-dimensional structure and subunit divisions. The most frequent causes of nasal defects include basal or squamous cell carcinoma, animal bites and trauma. The reconstruction approach varies depending on factors such as the defect’s size, the affected subunit of the nose, the condition and quality of the surrounding tissues and the surgeon’s expertise. Commonly employed surgical techniques for nasal reconstruction include the forehead flap, nasolabial flap, Rieger flap, bilobed flap, and free autologous skin graft. We present a clinical case of a patient with a full-thickness nasal alar defect who underwent three-layer reconstruction with a combination of an inverted skin flap- for the internal lining, a conchal graft to substitute the missing alar cartilage and a forehead flap for external coverage. One of the challenges of nasal reconstruction surgery is to restore a full-thickness defect, especially the internal nasal lining. We offer a different perspective on this problem, showcasing considerable advantages, as there are limited literature data on this method.

Design and simulation of neutron radiography system for an aqueous homogeneous solution reactor

AHR reactors are known for the production of radiopharmaceuticals. The ARGUS reactor is one of the most famous of these reactors, which has been designed originally for radioisotopes production. The ARGUS reactor produces a suitable neutron flux that can be used for other applications such as neutron radiography (NR). Here, a NR system is designed step by step using the Monte Carlo method. The length of the collimator, divergence angle, diameter of the aperture, and thermal column dimension are designed. The designed aperture and thermal column are selected from boron carbide and heavy water, respectively. The depth of the thermal column is changed until the ratio of thermal neutrons to total neutrons (TNC) reached above 90%. The hole inside the thermal column is designed and internal lining is done. The inner lining is made of cadmium and had a thickness of 1 mm, and the space between the inner and outer lining is filled with lead. To reduce the gamma dose to acceptable values, the position of the collimator is changed instead of using a gamma filter. By changing the depth of the hole and creating the convergence angle to the hole, the flux of thermal neutrons will be 1.8E+6 n.cm−2s−1 that satisfy the IAEA suggested values for NR. Then, the uniformity of the radiation field of the neutron flux output from the collimator is obtained. At the end, images of SI and BPI standards are recorded. The good quality and contrast of these images showed the acceptable design of the NR system for the ARGUS reactor.

Attenuated Total Reflectance–Fourier Transform Infrared (ATR-FTIR) Spectroscopy Combined With Deep Learning for Classification of Idiopathic Recurrent Spontaneous Miscarriage (IRSM)

Idiopathic recurrent spontaneous miscarriage (IRSM) is characterized by the repeated losses of two or more clinically detected pregnancies before 24 week of gestation with the cause remaining unknown. We aim to ascertain whether attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy with deep learning (DL) can accurately distinguish IRSM from controls. Endometrial tissue (internal lining of the uterine cavity) was collected from 20 women with IRSM and 20 controls during window of implantation. ATR-FTIR spectroscopy was used to acquire spectra (400–4000 cm−1) from three random locations across each specimen and averaged. Multivariate analysis was used to assess group differentiation. Furthermore, DL classifiers were implemented to predict IRSM. Hierarchical cluster analysis (HCA) demonstrated distinct clustering of the two groups. The principal component analysis (PCA) loading plot indicated contributions from amide I, II and III bands, symmetric methyl (CH3) bending of proteins, lipids, nucleic acids, asymmetric stretching of CH2 due to lipids, collagen, and glucose in discriminating between IRSM and controls. Supervised orthogonal projections to latent structures discriminant analysis (OPLS-DA) exhibited optimized discrimination between the groups. Convolutional neural network (CNN) and variational autoencoder-artificial neural network (VAE-ANN) classifiers exhibited good performance and showed classification accuracy of 94% and 94% and F1 scores (mean of recall and precision) of 95% and 93%, respectively. The optimal area under the receiver operating characteristic curve (AUC) value of both CNN and VAE-ANN was 0.94. ATR-FTIR spectroscopy combined with DL approach is promising for understanding complex disease pathophysiology and enabling early prediction.

CLINICOMORPHOLOGICAL FEATURES, DIAGNOSTIC AND TREATMENT OF CYSTS OF THE MINOR SALIVARY GLANDS

Small salivary gland cysts occupy a large percentage in the structure of oral cavity diseases in children and adults.
 The aim of the study is to determine the main diagnostic criteria and treatment tactics for patients with small salivary gland cysts.
 Materials and methods. 5 adult patients aged from 21 to 50 years and 2 children aged from 3 and 16 years were examined and surgical removal of small salivary gland cysts was performed. Pathohistologic studies of biopsy material were performed.
 Results obtained. Women (85.7%) prevail among the patients with cysts of the minor salivary gland. The average age of the patients was 27,0±6,1 years. The most frequent localization of small salivary gland cysts was the mucous membrane of the lower lip (85,7%). In 5 patients it was confirmed that the cause of cyst formation was mechanical trauma, namely biting or bruising of the lower lip. Clinically, a cyst of the minor salivary gland was a single oval or rounded mass with a size ranging from 0.4 to 1.1 cm. The average size of the cyst was 0.69±0.08 cm in diameter.
 According to the results of the pathohistological examination, the extravasation type of cyst of the minor salivary gland was determined in 3 patients, the retention cyst was also determined in 3 patients on the lower lip. A superficial extravasation cyst has been diagnosed on a soft palate in a woman aged 50 years old.
 In 3 patients, cystectomy was carried out in a traditional surgical method, in 4 patients with the use of a high-intensity diode laser. Hyaluronic acid gel hyaDENT BG was used to accelerate wound healing after laser ablation.
 Conclusion. Based on literature analysis and own clinical observations, the main etiological factors and clinical-morphological signs of various clinical variants of cysts of the minor salivary glands were determined. It is shown that only the mucous retention cyst is a true cyst, because it histologically has an internal epithelial lining.

Bio-evaluations of sericin coated hesperidin nanoparticles for gastric ulcer management

Gastric ulcers are worrying, and their worsening conditions may result in bleeding in the internal lining of the stomach. The problem is annoying, and both patients and professionals are still not satisfied with the available treatment options. Hesperidin, a flavonoid molecule with potent anti-inflammatory and antioxidant effects, can work like witchcraft to repair gastric ulcers and preserve the stomach lining. Here, we employed a strategy that involved covering the surface of the nano-lipid carriers (NLCs) with sericin before encasing the hesperidin within (Se-He-NLC). Sericin, a biodegradable polymer increases the muco-adhesion with stomach lining and deployment of hesperidin in controlled manner. Se-He-NLCs were physico-chemically characterized for drug loading, encapsulation, particle size, morphology, drug release, chemical stability, and chemical bonding. The nanocarriers showed first order drug release in a controlled manner. Se-He-NLCs showed better in vitro permeation and ex vivo mucoadhesion, thereby by promoting the in vivo bioavailability. Se-He-NLCs also promoted the reduced glutathione (GSH) and glutathione-S-transferase (GST) levels by 2.24- and 1.61-folds, respectively in the stomach lining, and also the regulation of superoxide dismutase (SOD) and catalase (CAT) activities parallel to the control group. In addition, tissues lipid hydroperoxides (LOOH) and myeloperoxidase (MPO) activity were reduced significantly with Se-He-NLCs administration. Se-He-NLC therapy of stomach ulcers in vivo demonstrated better binding ratio and ulcer healing potential. This approach reveals huge capacity for delivering therapies to treat gastric ulcers based on the clinical significance of sericin coated hesperidin nanocarriers in gastric ulcer treatment.

Endothelial dysfunction in obesity

ABSTRACT Obesity is a condition caused by excess fat buildup, often measured using the body mass index (BMI) and categorized into underweight, normal weight, and obesity. Obesity is a global epidemic with an alarmingly rising incidence. Obesity is closely associated with insulin resistance, metabolic disorders, hypertension, and atherosclerosis, as well as endothelial dysfunction, which leads to numerous diseases. Noncommunicable diseases are significantly associated with high BMI and can have a negative impact on physical and psychological conditions. Endothelium, the internal lining of blood vessels, controls vascular tone, inflammation, and clotting processes. Endothelial dysfunction is a clinical complication characterized by the loss of normal endothelial cell homeostatic mechanisms. Reduced bioavailability of nitric oxide can be moderately related to endothelial dysfunction, which promotes vascular abruptions such as thrombosis, inflammation, plaque rupture, and other related conditions. The rise in obesity incidence and its global status highlights the urgent need to address responsible factors such as sedentary lifestyles, bad food habits, and globalization. Factors such as dietary modifications, low-cost food and beverages, and liberalization of international trade contribute to obesity, whereas factors such as genetics, poor diet, and lack of physical activity can also contribute to obesity.

Forehead Flap Practices: A Cross-Sectional Survey of Facial Plastic and Reconstructive Surgeons.

Background: The paramedian forehead flap (PMFF) is a well-established technique utilized for reconstruction of complex nasal defects. Objective: To identify the different techniques and management of patients undergoing PMFF reconstruction and compare these with current literature. Methods: Members of the American Academy of Facial Plastic and Reconstructive Surgery were sent a practice survey highlighting various nuances in PMFF reconstruction. The survey included questions about flap design, operative techniques, and perioperative care. Results: In total, 172 responses were received (14% response rate). Mean years of practice after fellowship was 15.8 years with most respondents performing either 1-5 (33.1%) or 6-10 (27.3%) PMFFs per year. Common practices included the use of general anesthesia, elevation of PMFF in the subgaleal plane (59.6%), and pedicle division at 3 weeks (80%) (p < 0.001). Complication rates ranged between 1% and 5%. The nose was the most common site for revision (p < 0.001) and the average number of secondary procedures after forehead flap division was 1.1 (standard deviation 0.81). The most variability in responses was seen for methods of internal lining reconstruction. Conclusion: Reconstructive surgeons frequently divide the PMFF pedicle at 3 weeks or later and have variable approaches to reconstruction of the internal lining with low complication rates overall.

Morinda Citrifolia (Noni) attenuated transcriptional and degenerative markers of cardiac toxicity in bisphenol A treated male wistar rats

Bisphenol A (BPA) is an endocrine disruptor that causes metabolic disruption. It is widely used in the manufacturing industry as an internal protective lining for food and beverage cans. Morinda citrifolia (Noni) is a known ethno-medicinal plant of Pantropical origin. The aim of this study was to investigate the effect of Noni aqueous extract (NAE) on transcriptional and degenerative markers of cardiac toxicity in Bisphenol A treated male Wistar rats. Twenty-four male Wistar rats were randomly assigned into four groups as: Control (Ctr: normal chow + vehicle: Olive oil), BPA (7 g/kg, orally), (NAE:500 mg/kg; orally), and NAE: (500 mg/kg + BPA;7g/kg orally). After six weeks of administration, animals were anesthetized with 0.8 mg Phenobarbitone intraperitoneally and blood was collected by cardiac puncture. Plasma and cardiac homogenate were sampled and data were analyzed using a one-way ANOVA followed by Bonferroni’s Post hoc test. Results are expressed as mean ± standard error of mean (SEM) and p < 0.05 were accepted as significant. Bisphenol A reduced significantly plasma and cardiac histone deacetylate (HDAC), Nitric oxide (NO) and adenosine and increased triglycerides (TG), lipoprotein (a) or Lp(a), tumor necrotic factor alpha (TNF-α), uric acid (UA), and (malondialdehyde) MDA when compared with control and noni-treated group. NAE increased HDAC and NO significantly compared to the control while reducing significantly TNF-α, catalase, MDA, TG, and Lp(a). In conclusion, NAE reduced Bisphenol A worsening cardiovascular risks through a significant positive epigenetic HDAC expression and increased neovascularization activities.

Ultrastructure of the female pedal gonad in Phoxichilidium femoratum (Chelicerata, Pycnogonida)

Phoxichilidium femoratum is a common species of sea spiders – a small and unique group of chelicerates with unusual adult anatomy. In particular, substantial parts of the reproductive system in pycnogonids (unlike euchelicerates) are located in the appendages. Existing studies of pycnogonid gonads are often limited to light-microscopic level, cover a small range of species, and focus on the contents of the gonad diverticula. Ultrastructural data are rare and contradictory, and the organisation of the gonad wall and the gonoducts is unknown. Here we present a detailed light and transmission electron microscopy-based examination of the pedal portion of the adult female reproductive system in Phoxichilidium femoratum Rathke, 1799. We describe its gross anatomy and the ultrastructure of the gonad diverticulum, oviduct and gonopore, as well as development of the oocytes. Each gonad diverticulum is enclosed in the extracellular matrix of the horizontal septum and bears some internal cellular lining. However, neither the gonad lining, nor the septum sheath cells, ever form a continuous epithelial layer. Oocytes, which undergo maturation in the diverticulum, remain, until very late in the process, attached to the gonad wall though specialised stalk cells. Interestingly, stalk cells do not participate in egg envelope or yolk formation: both are synthesized endogenously in the oocytes. The oviduct is supplied with musculature, which assists in egg transport to the gonopore, whereas the gonopore itself is surrounded by specialised glands.

Maxillary and total nasal reconstruction with a scapulo dorsal perforator flap

Facial gunshots injuries remain challenging and present functional and aesthetic problems. Such defects generally require composite tissue flaps for reconstruction. Rebuilding the palate and the maxilla is especially delicate because it requires reconstitution of the facial buttresses, and replacement of bony hard palate, based on occlusion, as well as the restoration of the thin intraoral and intranasal lining which normally constitute the soft palate. Various methods of reconstruction have been applied to this area in search of an ideal soft tissue and bone flap to restore the bony framework of the maxilla and palate while providing an internal lining. The scapula dorsal perforator flap is used in the case of a patient to successfully reconstruct the palate, the maxilla and the nasal pyramid in one stage. Free tissue transfer using thoracodorsal perforator flaps and scapula bone free flap have been already described in literature but never to perform the nasal pyramid reconstruction at the same time. Good functional and aesthetic results have been obtained in this case. This article also reviews, through the authors experience and literature, anatomical landmarks, indications, technical surgical tricks, advantages and disadvantages of this flap for palatal, maxillary and nose reconstruction.

Expanded forehead flap in Asian nasal reconstruction

This article reviewed our experience of Chinese nasal reconstruction over 12 years and evaluated the effect of expanded forehead flap both aesthetically and functionally. The special skin type and other anatomic features of Chinese patients was understood thoroughly during the treatment. This article thus catered for the need of multiracial nasal reconstruction. We analyzed existing clinical data and demonstrated a typical case in detail. The postoperative result supported our strategy which advocated the extensive application of expanded forehead flap, together with flip scar flap as the internal lining. The features of Chinese patients also prompted the use of costal and auricular cartilage. Emerging technology like 3D-printing would benefit nasal reconstruction from more aspects.

UTILIZAÇÃO DE TESTES DE RECEBIMENTO E ACOMPANHAMENTO COMO FERRAMENTAS DE CONTROLE DE QUALIDADE DO REVESTIMENTO REFRATÁRIO APLICADO EM CALCINADORES: UM ESTUDO DE CASO

Refractories are ceramic materials, made from clay minerals that have high melting point inorganic oxides, generally used as internal lining of alumina calciners because they can withstand many types of wear mechanisms when subjected to high temperatures, such as mechanical and thermal stresses. However, several aspects can compromise the integrity of this material, which in turn can lead to unexpected and emergency equipment shutdowns, affecting the production and maintenance costs of refineries. Therefore, this work proposes the implementation of a new testing methodology that seeks to compare the properties specified by the manufacturers in the technical data sheets (FDT) with the properties of the material received, and consequently improve the quality control. Thus, characterization tests were carried out for four dense refractory castable installed in an alumina calciner. The samples were subjected to two types of tests in order to evaluate the properties and performance of the material received and applied. In the receiving test, the tests performed were as follows: liquid absorption, porosity and apparent density (110°C); erosion resistance (after firing at 1000 °C for 5 hours, as well as the others tests followed by their respective temperatures); and permanent linear change (1000°C). As for the installation test, the tests considered were: erosion resistance (1250°C); permanent linear change (1250°C); thermal shock resistance (1250°C); hot modulus of rupture (1250°C); and refractoriness under load (1600 °C). After analyzing the results, a deviation was found in relation to the analyzed properties - such as mechanical strength and refractoriness -, as they presented values below those specified by the suppliers in their technical data sheets. Thus, the importance of receiving and monitoring tests as efficient tools in the quality control of the refractory used is evident, based on the need to specify materials that meet operational conditions and/or project requirements, with a focus on performance, safety and operational availability (production).

Seismic response mechanisms of casing-shape composite tunnel lining: Theoretical analysis and shaking table test verification

In high-intensity seismic zones tunnel lining is generally utilized to provide efficient protection against tunnel collapse by withstanding pressure under strong earthquake events. However, this can be a challenging task in the case of fault-crossing tunnels, since tunnel lining follows the deformation of surrounding rock. To address this issue, the casing-shape tunnel lining system is proposed to reduce the constraint effects of surrounding rock on the lining structure by using an internal and external lining with a buffer layer employed in between. This research aims to investigate the rock-structure interaction and seismic response mechanism of casing-shape tunnels, both theoretically and experimentally, to facilitate the adoption of the proposed system. To develop a practical mechanical model for parametric study, the casing-shape tunnel lining is simplified as a Timoshenko composite beam. The theoretical analysis results indicate that the external lining and buffer layer can effectively reduce the earthquake-induced internal forces on the internal lining and there is an optimal length of casing-shape lining to balance cost-effectiveness with seismic resistance protection. To validate the proposed simplified model of casing-shape tunnel lining, a series of shaking table model tests are then performed on large-scale casing-shape lining models with earthquake-induced fault slippage under incremental input intensity excitations. The results demonstrate that: (i) the inclined angle of fault considerably affects the adopted length of casing-shape tunnel lining, (ii) the fault slippage shears the external lining directly leading to severe seismic damage at arch springing and invert, and (iii) the upper part of external lining and the whole internal lining generally exhibit a satisfying level of protection. This highlights the need to select appropriate cross-section shapes and structural materials for the construction of casing-shape tunnel lining systems. The outcomes of this study can provide theoretical foundation and experimental evidence for the seismic response mechanisms of casing-shape tunnel lining in practical applications.

Leaching of chromium and lead from the cement mortar lining into the flowing drinking water shortly after pipeline rehabilitation

Internal cement lining protection is used for both new and renovation of old cast iron water pipes. However, under unfavorable conditions, contaminants may be released from the cement lining into the drinking water shortly after the rehabilitation of old or installation of new water pipes. This paper proposes a mathematical model for the leaching of heavy metals from the inner cement lining of the pipe into the flowing water, taking sorption into account. Previously, mathematical models described in the literature for the leaching of contaminants from a cement coating into water only addressed static conditions or did not consider sorption. Experimental verification of the mathematical model under dynamic conditions showed very good agreement between calculated and measured results and confirmed the necessity of taking into account the sorption phenomenon. It also demonstrated the need for periodic water changes during laboratory experiments to describe the release of contaminants from the cement coating into the flowing water. Based on the results of laboratory experiments and the developed mathematical model, the concentrations of heavy metals at the ends of different lengths of drinking water supply pipeline sections after their eventual rehabilitation by cementation were calculated. Maximum lead concentrations at the end of 30, 23 and 13-km cemented sections of the pipeline were 2.0; 1.5 and 1.0 mg/m 3 , respectively. In contrast, chromium concentrations were 2.5; 1.6 and 0.9 mg/m 3 , respectively. Although all of these values are below the drinking limits, they can reach them if there is another additional source of contaminants or if the water stagnates periodically. The developed methodology and mathematical model allow to select the maximum length of the water main section that can be renovated or replaced at one time without significant impact on drinking water quality. • Modeling the leaching of heavy metals from an internal cement coating into flowing drinking water. • Significant effect of concentration gradient at the water-cement interface on metal leaching intensity. • Slight increase in heavy metal concentrations in drinking water flowing through newly cement-lined pipeline.

MUCOADHESIVE PATCHES OF PREGABALIN EFFECTIVE IN THE TREATMENT OF NEUROPATHIC PAIN: A SYSTEMATIC REVIEW

Although the oral pathway is the recommended mode of intake for the majority of medications, it does have some drawbacks i.e., pre-systemic metabolism in the liver, gastrointestinal disturbance, and enzyme degradation. It offers a safe method for administration of medications and easy way to reverse the intake of toxic substances by easy removal of dosage form from oral cavity. This review was designed to critically acknowledge the evaluation parameters, mechanism of cohesion, polymers used in mucoadhesive formulation, main method of preparations (solvent casting &amp; milling), advantages &amp; disadvantages of mucoadhesive patches. This review consists an extensive survey of literature from the Scopus, PubMed, Springer Nature and other international reputed sources. Since the middle of 1980s, the idea of muco-adhesion has acquired extensive interest in drug innovation. Muco-adhesive dosage structures were developed for oral delivery like adhesive unit dosage form, adhesive gels and adhesive patches. The epithelium that forms the internal lining of buccal mucosa is the primary obstruction for the drugs absorption. Muco-adhesion is defined as an interfacial adhesion in which one synthetic mucoadhesive polymer and the other mucin layer (mucosal tissue), are hold together by an attraction force. 'Mucoadhesive’ is defined as an artificial substance being capable of making interaction with mucus membranes and binding them together for extended or delayed periods of time. However, delivering therapeutically for the therapy of both systemic and topical disorders would take a lot more work with these innovative mucoadhesive formulations. In conclusion, it facilitates the target therapy by enriching efficacy or intrinsic activity. Keywords: mucoadhesive patch, solvent-casting, milling, mechanism of muco-adhesion, polymers

VITOM-3D assisted paramedian forehead flap for nasal reconstruction

BackgroundThe study was designed with the purpose of showing the potential advantages of the VITOM-3D assisted paramedian forehead flap for nasal reconstruction. MethodsA 72 years-old female patient presented to our department with a wide left nasal defect. On her clinical history she referred a basal cell carcinoma of the left nasal skin treated with multiple excision in another center without reconstruction. On clinical examination, we observed the absence of the left nasal tip, columella, upper lateral and lower lateral cartilage. In our experience the paramedian forehead flap based on supratrochlear artery is a feasible reconstruction (Shokri, T., et al).The first surgeon (Dr. Placentino) along with the head and neck team decided to reconstruct the nasal defect assisted by the 3D 4 K exoscope (VITOM®; Karl Storz, Tuttlingen, Germany). ResultsThe goal of reconstruction is to carefully evaluate the nasal defects and rebuild the nose as close as possible to its original shape with the multilayer technique, creating the internal lining, the intermediate bony-cartilage structure and external skin. (Kim, I.A., et al). The exoscope allowed us to reconstruct the inner layer with the mucoperiostal septal flap, middle layer with auricular cartilage and the external skin through the elevation of the paramedian forehead flap. The flap is elevated from cranio-caudal direction including skin, subcutaneous tissue, frontalis muscle and associated fascia or periosteum. Donor site was primarily closed with the exception of a small defect. Post-operative period was uneventful, and after a period of 4 weeks when vascularization was complete, the patient underwent pedicle excision. At the recent 6 months follow-up, the flap had healed completely with the shape of nose restored with good symmetry. ConclusionHigh-definition (4 K), three-dimensional (3D) exoscope are being used to perform a growing number of head and neck surgeries (Bartkowiak, E., et al). However, the use of the 3D exoscope in the nasal reconstruction has not been previously described. In our opinion the potential advantages of this technique are, firstly, to achieve a better magnification and to improve the vision of anatomical structure that leads to a better functional and aesthetic result, secondly, to reduce surgical times. High-definition allowed us to highlight the scar tissue and preserve as much healthy tissue as possible. In addition, we underline the use of the exoscope for a better remodeling of cartilage.

Remote Rotary Mixing and Spraying of Plural Component Protective Coating for Underground Pipe Internal Rehabilitation Lining

Trenchless rehabilitation of underground pipes is increasingly important for city operation. A miniature robotic spraying system is developed to rehab buried pipes by remote spraying plural component protective coating to form lining on the original pipe inner wall. The system demonstrated three novelties, namely the remote mixing and spraying under low pressure, the long-range delivery of viscous coating using low pressure, and the hybrid hose step-down design, that make the system objective feasible. This letter presents the system setup and the remote rotary mixing and spraying mechanism. The mechanism is composed of a mixing chamber and a spray bit assembly. Half of the spray bit assembly with blade mixer feature stays in the mixing chamber for coating mixing, while the other half with rotary atomizer feature stays outside the chamber for spraying. Coatings are fed to the mixing chamber on ratio using low pressure and sprayed out by the high-speed rotation after mixing. The system setup and the mechanism are experimentally validated. The proposed method further opens the possibility of performing remote mixing and spraying over a long distance.

A Sustainable Approach to Build Insulated External Timber Frame Walls for Passive Houses Using Natural and Waste Materials

This paper presents structures of timber-framed walls designed for passive houses, using natural and waste resources as insulation materials, such as wool, wood fibers, ground paper, reeds (Phragmites communis), and Acrylonitrile Butadiene Styrene (ABS) wastes. The insulation systems of stud walls composed of wool–ABS composite boards and five types of fillers (wool, ABS, wood fibers, ground paper, and reeds) were investigated to reach U-value requirements for passive houses. The wall structures were designed at a thickness of 175 mm, including gypsum board for internal wall lining and oriented strand board (OSB) for the exterior one. The testing protocol of thermal insulation properties of wall structures simulated conditions for indoor and outdoor temperatures during the winter and summer seasons using HFM-Lambda laboratory equipment. In situ measurements of U-values were determined for the experimental wall structures during winter time, when the temperature differences between outside and inside exceeded 10 °C. The results recorded for the U-values between 0.20 W/m2K and 0.35 W/m2K indicate that the proposed structures are energy-efficient walls for passive houses placed in the temperate-continental areas. The vapour flow rate calculation does not indicate the presence of condensation in the 175 mm thick wall structures, which proves that the selected thermal insulation materials are not prone to degradation due to condensation. The research is aligned to the international trend in civil engineering, oriented to the design and construction of low-energy buildings on the one hand and the use of environmentally friendly or recycled materials on the other.

Acoustical Treatments on Ventilation Ducts through Walls: Experimental Results and Novel Models

Sound reduction is complex to estimate for acoustical treatments on ventilation ducts through walls. Various acoustical treatments are available for ventilation ducts, including internal lining (absorption along the inner perimeter), external lagging (external sound insulation), silencer, and suspended ceilings. Previous studies have examined how silencers and the internal lining affect the sound transmission of ventilation ducts. However, there are few theories to predict the effect of external lagging in combination with ventilation ducts and how the total sound reduction is affected. This article aims to investigate different acoustical treatments and develop theoretical models when external lagging with stone wool is used to reduce flanking sound transmission via the surface area of ventilation ducts. Theoretical models are developed for external lagging and compared with measurement data. Measurements and theory are generally in good agreement over the third-octave band range of 100–5000 Hz. The developed models clarify that the distance closest to the wall has the main impact on sound reduction for a combined system with a wall and a ventilation duct. Suspended ceilings and silencers are found to be enough as acoustical treatments for certain combinations of ventilation ducts and walls. However, external lagging seems to be the only effective solution in offices and schools when a large ventilation duct passes through a wall with high sound reduction.

Reconstruction of a large nasal defect using a folded forehead flap: a case report

Forehead flaps are widely used to reconstruct nasal defects. The authors report a case wherein a folded forehead flap was used to reconstruct a large nasal defect after wide excision of squamous cell carcinoma. A 65-year-old man was diagnosed with squamous cell carcinoma by a punch biopsy conducted at the dermatology department, and the mass was located in the left nasal vestibule. A forehead flap was planned to cover the full-thickness defect that occurred after wide excision. A flap with an extended transverse skin paddle was designed; thereafter, the distant part of the flap was folded up to the nasal lining inside the nose. The interpolation flap was properly maintained for 3 weeks, and flap division was performed. The reconstructed nose exhibited symmetry during a 5-month observation period. A folded forehead flap is a surgical option when considerable nasal restoration, including soft tissue and the internal lining, is necessary.