Active Neutralizing Mats for Corrosive Chemical Storage.

Laboratories and industries that handle chemicals are ubiquitously prone to leakages. These may occur in storage rooms, cabinets or even in temporary locations, such as workbenches and shelves. A relevant number of these chemicals are corrosive, thus commercial products already exist to prevent material damage and injuries. One strategy consists of the use of absorbing mats, where few display neutralizing properties, and even less a controlled neutralization. Nevertheless, to the authors' knowledge, the commercially available neutralizing mats are solely dedicated to neutralizing acid or alkali solutions, never both. Therefore, this work describes the development and proof of a completely novel concept, where a dual component active mat (DCAM) is able to perform a controlled simultaneous neutralization of acid and alkali leakages by using microencapsulated active components. Moreover, its active components comprise food-grade ingredients, embedded in nonwoven polypropylene. The acid neutralizing mats contain sodium carbonate (Na2CO3) encapsulated in sodium alginate microcapsules (MC-ASC). Alkali neutralizing mats possess commercial encapsulated citric acid in hydrogenated palm oil (MIRCAP CT 85-H). A DCAM encompasses both MC-ASC and MIRCAP CT 85-H and was able to neutralize solutions up to 10% (v/v) of hydrochloric acid (HCl) and sodium hydroxide (NaOH). The efficacy of the neutralization was assessed by direct titration and using pH strip measurement tests to simulate the leakages. Due to the complexity of neutralization efficacy evaluation based solely on pH value, a thorough conductivity study was performed. DCAM reduced the conductivity of HCl and NaOH (1% and 2% (v/v)) in over 70%. The composites were characterized by scanning electron microscopy (SEM), differential calorimetry (DSC) and thermogravimetric analysis (TGA). The size of MC-ASC microcapsules ranged from 2 µm to 8 µm. Finally, all mat components displayed thermal stability above 150 °C.

Middle Vault Changes After Humpectomy by Spare Roof Technique Versus Component Dorsal Hump Reduction.

Objectives: To compare the effect of two different humpectomy techniques in the internal nasal valve (INV) angle in human anatomic specimens. Methods: Seven human anatomic specimens (14 heminoses) were included. A strip of subdorsal septal cartilage was removed and, in each nose, the right side of the middle roof lied intact over and was sutured to the septal cartilage (spare roof technique [SRT]), whereas in the left side the upper lateral cartilage was folded and sutured to the septal cartilage (component dorsal hump reduction [CDHR]). The INV angle was measured pre- and postoperatively. Results: Mean age of the specimens was 69.86 (60-80) years. Five were female. CDHR resulted in a mean change of +1.71 ± 3.12° (p = 0.197), +0.62 ± 6.89° (p = 0.817) and +6.97 ± 6.84° (p = 0.036) after resection of 2, 4, and 6 mm of septal cartilage, respectively. SRT resulted in a mean change of +1.27 ± 2.37° (p = 0.207), +6.89 ± 1.19° (p < 0.001), and +12.55 ± 1.79° (p < 0.001) after resection of 2, 4, and 6 mm of septal cartilage, respectively. In SRT, the amount of septal cartilage resection presented a significant correlation with change in INV angle (r = 0.813, p < 0.001). Conclusions: In this human anatomic study, SRT significantly increased INV angle.

Shaved Cartilage Gel Versus Diced Cartilage on Final Dorsal Camouflage: Prospective Study of 200 Patients.

Importance: Diced cartilage (DC) is a reported technique that has been used for dorsal camouflage after reduction rhinoplasty. Nevertheless, there are certain issues regarding its use on nasal dorsum, especially its variable resorption rate and risk of graft distortion or migration, especially in thin-skinned patients. Recently, regenerative medicine protocols have been used to overcome drawbacks of methods based on DC. Thus, cartilage embedded in platelet-rich fibrin (PRF) has been described as a promising and reliable alternative to existing procedures. Objective: To compare long-term aesthetic outcomes of two different techniques for dorsal camouflage: DC versus shaved cartilage plus platelet-rich fibrin (SC+PRF)-shaved cartilage gel. Design, Setting, and Participants: This is a prospective, interventional, and longitudinal study at an academic tertiary medical center. Participants were 200 consecutive patients undergoing primary reduction rhinoplasty by spare roof technique (SRT) or component dorsal reduction (CDR). Materials and Methods: The inclusion criteria were primary rhinoplasty, in Caucasian patients with dorsal hump, and camouflage of the dorsum by DC or SC+PRF. Exclusion criteria were ≤18 years of age, revision rhinoplasty and reconstructive rhinoplasty for neoplasic or severe traumatic nasal deformities. The "Utrecht Questionnaire for outcome assessment in aesthetic rhinoplasty" was used. Patients answered it before and after surgery (3 and 12 months after). Results: The study population included 200 patients divided into two groups considering the type of dorsal camouflage: DC (n = 132) and shaved cartilage gel (n = 68). The mean age at the time of surgery was 35.44 years (standard deviation ±9.78) and the study population included 130 females (65.0%) and 70 males (35.0%). Regarding aesthetic outcomes, analyses of postoperative means showed a significant improvement, in both groups, over time. However, self-assessment, based on the visual analogue scale (VAS), at 12 months postsurgery, was higher for patients with SC+PRF than with DC (p = 0.004). Twelve months after surgery, patients with thin skin had better aesthetic outcome with SC+PRF than with DC (p = 0.001). For both reduction rhinoplasty techniques, aesthetic outcomes, based on the VAS at 12 months after surgery, were significantly better for patients with SC+PRF (SRT: p = 0.016; CDR: p = 0.004). For both rhinoplasty approaches, either open or closed, aesthetic outcomes, based on the VAS at 12 months after surgery, were significantly better for patients with SC+PRF (closed approach: p = 0.046; open approach: p = 0.017). Conclusions: SC+PRF provides better long-term aesthetic outcomes, not only for thin-skinned patients, but also for patients who had undergone rhinoplasty by a structured or preservation technique, or by an open or closed approach, for dorsal hump reduction.

Spare Roof Technique Versus Component Dorsal Hump Reduction: A Randomized Prospective Study in 250 Primary Rhinoplasties, Aesthetic and Functional Outcomes.

BACKGROUND: Most Caucasian aesthetic rhinoplasty patients complain about having a noticeable hump in profile view. Taking the integrity of the middle vault into consideration, there are 2 ways to dehump a nose: the structured technique and the preservation technique. OBJECTIVES: The aim of this study was to compare the aesthetic and functional outcomes of 2 reduction rhinoplasty techniques. METHODS: We performed a prospective, randomized, interventional, and longitudinal study on 250 patients randomly divided into 2 groups: the component dorsal hump reduction group (CDRg) (n = 125) and the spare roof technique group (SRTg) (n = 125). We utilized the Utrecht Questionnaire for Outcome Assessment in Aesthetic Rhinoplasty. Patients answered the questionnaire before the surgery, and at 3 and 12 months after surgery. In addition, we utilized a visual analog scale (VAS) to score nasal patency for each side. RESULTS: Analyses of the preoperative and postoperative aesthetic VAS scores showed a significant improvement in both groups, from 3.66 to 7.00 (at 3 months) to 7.35 (at 12 months) in the CDRg, and from 3.81 to 8.14 (at 3 months) to 8.45 (at 12 months) in the SRTg. Analyses of postoperative means of aesthetic VAS scores showed a significant improvement in both groups over time. However, aesthetic improvement was higher in the SRTg than in the CDRg at both 3 (P < 0.001) and 12 months (P < 0.001) postsurgery. Analyses of the mean functional VAS scores showed a significant improvement with both techniques, with a better result for the SRTg. CONCLUSIONS: The SRT is a reliable technique that can help deliver consistently better aesthetic and functional results than CDR for reduction rhinoplasty in Caucasian patients with a dorsal hump.

Thermo-Mechanical Behaviour of Human Nasal Cartilage.

The aim of this study was to undergo a comprehensive analysis of the thermo-mechanical properties of nasal cartilages for the future design of a composite polymeric material to be used in human nose reconstruction surgery. A thermal and dynamic mechanical analysis (DMA) in tension and compression modes within the ranges 1 to 20 Hz and 30 °C to 250 °C was performed on human nasal cartilage. Differential scanning calorimetry (DSC), as well as characterization of the nasal septum (NS), upper lateral cartilages (ULC), and lower lateral cartilages (LLC) reveals the different nature of the binding water inside the studied specimens. Three peaks at 60-80 °C, 100-130 °C, and 200 °C were attributed to melting of the crystalline region of collagen matrix, water evaporation, and the strongly bound non-interstitial water in the cartilage and composite specimens, respectively. Thermogravimetric analysis (TGA) showed that the degradation of cartilage, composite, and subcutaneous tissue of the NS, ULC, and LLC take place in three thermal events (~37 °C, ~189 °C, and ~290 °C) showing that cartilage releases more water and more rapidly than the subcutaneous tissue. The water content of nasal cartilage was estimated to be 42 wt %. The results of the DMA analyses demonstrated that tensile mode is ruled by flow-independent behaviour produced by the time-dependent deformability of the solid cartilage matrix that is strongly frequency-dependent, showing an unstable crystalline region between 80-180 °C, an amorphous region at around 120 °C, and a clear glass transition point at 200 °C (780 kJ/mol). Instead, the unconfined compressive mode is clearly ruled by a flow-dependent process caused by the frictional force of the interstitial fluid that flows within the cartilage matrix resulting in higher stiffness (from 12 MPa at 1 Hz to 16 MPa at 20 Hz in storage modulus). The outcomes of this study will support the development of an artificial material to mimic the thermo-mechanical behaviour of the natural cartilage of the human nose.

Spare Roof Technique: A New Technique for Hump Removal-The Step-by-Step Guide.

Humpectomy is one of the most common steps in reduction rhinoplasty among Caucasian patients. The most widespread procedures to address hump removal are both the "en bloc humpectomy" (with reconstruction of the middle third with spreader grafts) and the "split hump technique" (with confection of spreader flaps). The spare roof technique, for rhinoplasty reduction, has been developed over the past 4 years. In this technique, the upper lateral cartilages are completely preserved-even the hidden part under the caudal aspect of the nasal bones. It consists of five main steps: step 1, the upper lateral cartilages are released from the dorsal aspect of the nasal septum; step 2, a 1-mm strip of the dorsal septum is taken in each movement as required; step 3, ostectomy of the caudal aspect of nasal bones, keeping the upper lateral cartilages intact and releasing the "lateral" (left and right) pyriform aperture ligament; step 4, classic medial and lateral osteotomies (closing the open bony roof); and step 5, suturing the upper lateral cartilages to the dorsal septum and thus avoiding the natural spring effect. The outcomes of the first 100 patients have been validated by a prospective, interventional, and longitudinal study performed on patients undergoing primary rhinoplasty by means of the spare roof technique. This study confirms that the spare roof technique significantly improved patient quality of life regarding nose function and appearance. It is a reliable technique that can help deliver consistently good results in Caucasian and Mediterranean patients with a dorsal hump seeking rhinoplasty.

Dorsal Hump Reduction Based on the New Ethmoidal Point Classification: A Clinical and Radiological Study of the Keystone Area in 138 Patients.

BACKGROUND: Hump resection often requires reorganization of the keystone area. OBJECTIVES: The authors sought to describe the importance of the point where the perpendicular plate of ethmoid joins the septal cartilage (SC) and the nasal bones (NB) (Ethmoidal point [E-point]) for hump resection surgical planning. METHODS: Measurements from mid-sagittal slices in nasal computed tomography scans taken in adult Caucasian patients between January 2015 and December 2018 were compared between patients seeking primary rhinoplasty due to a nasal hump and patients not seeking rhinoplasty (control group). Patients with previous nasal surgery or trauma, genetic or congenital facial disorders, and high septal deviation were excluded. The length of overlap between NB and SC was compared between the 2 groups. The location of the E-point in relation to the beginning of the nasal hump in the cephalocaudal direction was documented in the patients seeking rhinoplasty. RESULTS: The study population included 138 patients, 69 seeking and 69 not seeking rhinoplasty (96 females). The mean age was 32.9 years (range, 18-55 years). The length of overlap between NB and SC was similar between both groups (11.7 ±â€…3.3 vs 10.8 ±â€…3.3; P = 0.235). The E-point was located before the beginning of the nasal hump in 97% (67/69) of nasal hump patients, and it could be found a mean distance of 2.3 (±2.3) mm cephalic to the latter. CONCLUSIONS: As a rule, the perpendicular plate of the ethmoid does not contribute to the nasal hump; therefore, only in exceptional cases should this be addressed while performing dorsal reduction.

Bone turnover markers in sheep and goat: A review of the scientific literature

ABSTRACT Bone turnover markers (BTMs) are product of bone cell activity and are generally divided in bone formation and bone resorption markers. The purpose of this review was to structure the available information on the use of BTMs in studies on small ruminants, especially for monitoring their variations related to diet, exercise, gestation and metabolic lactation state, circadian and seasonal variations, and also during skeletal growth. Pre-clinical and translational studies using BTMs with sheep and goats as animal models in orthopaedic research studies to help in the evaluation of the fracture healing process and osteoporosis research are also described in this review. The available information from the reviewed studies was systematically organized in order to highlight the most promising BTMs in small ruminant research, as well as provide a wide view of the use of sheep and goat as animal models in orthopaedic research, type of markers and commercial assay kits with cross-reactivity in sheep and goat, method of sample and storage of serum and urine for bone turnover markers determination and the usefulness and limitations of bone turnover markers in the different studies, therefore an effective tool for researchers that seek answers to different questions while using BTMs in small ruminants.