Structural Failure Rate Research Articles

Negligible Building Failures in Rivers State — A Literature Review

Through an in-depth literature review, this study explores the factors influencing the minimal building failures in Rivers State, Nigeria. Unlike many other regions, Rivers State is renowned for its exceptionally low rate of structural failures, highlighting a stark contrast to widespread construction safety issues elsewhere. The study identifies several critical factors behind this achievement: strict legal frameworks, premium building materials, skilled labor, successful community collaboration, favorable environmental conditions, and technological integration. The findings emphasize the importance of upholding strict building regulations and norms to maintain high construction standards. Regular inspections and compliance checks ensure adherence to defined safety protocols, significantly reducing the likelihood of structural problems. The study also underscores the significance of superior building materials and advanced technologies, such as Building Information Modeling (BIM) and smart construction tools, in enhancing project planning and execution. A proficient labor force, continuously trained and certified, is essential for achieving construction excellence. Ongoing professional development programs keep workers updated on the latest methods and safety precautions. Additionally, positive community engagement is crucial for monitoring construction activities, with residents actively reporting deviations from approved plans and unsafe practices, fostering a culture of accountability and vigilance. Favorable environmental conditions, including stable geographical and climatic factors, contribute to the rarity of building failures. Mandatory environmental impact assessments for new projects ensure potential risks are identified and mitigated early in the planning process. Rivers State’s economic stability supports sustained investment in infrastructure and maintenance, facilitated by government initiatives that encourage the use of high-quality building materials. Technological integration, particularly through real-time monitoring and data-driven decision-making, further enhances construction safety by enabling continuous oversight and timely interventions, thus reducing the risk of failures. Rivers State’s approach to construction safety offers valuable lessons for other regions aiming to improve building standards and reduce structural failure rates. This comprehensive analysis highlights the necessity of a multifaceted strategy to enhance and maintain building integrity, resulting in safer and more resilient built environments.

Bridging Reconstruction With Interpositional Dermal Allograft Has Superior Healing Than Does Maximal Repair for Treatment of Large to Massive, Irreparable Rotator Cuff Tears—Secondary Analysis of a Randomized Control Trial

PurposeThe purpose of this study was to compare the radiographic results of bridging rotator cuff reconstruction (BRR) with dermal allograft and maximal repair for large or massive, irreparable rotator cuff tears. MethodsThis was a secondary analysis of data from a single-center, blinded-observer, randomized controlled trial that examined clinical outcomes of BRR compared to maximal repair. A sample size of 30 patients with MRI-proven large or massive (>3 cm), retracted rotator cuff tears and/or involvement of 2 or more tendons were randomly allocated to 1 of 2 groups: maximal repair or BRR using dermal allograft. MRIs were obtained preoperatively and 1 year postoperatively. The primary outcome of this study was the retear rate on MRI. Secondary outcomes included progression of muscle atrophy and fatty infiltration. ResultsThere was no difference in age or preoperative tear size between the two groups. Patients treated with BRR had decreased retear rate (21%) compared with patients who received maximal repair alone (87%). There was no difference in the number of patients who had progression of muscle atrophy (p=0.088 for supraspinatus and p=0.738 for infraspinatus) or fatty infiltration (p=0.879 for supraspinatus and p=0.693 for infraspinatus) between the two groups. A significant increase in mean postoperative supraspinatus muscle atrophy was identified in the maximal repair group (p=0.034). ConclusionThe results of this secondary analysis of a randomized controlled trial comparing radiographic results of maximal repair vs BRR using dermal allograft in the treatment of large or massive rotator cuff tears show that BRR results in a significantly reduced structural failure rate and a trend towards better preservation of supraspinatus muscle mass compared to maximal repair.

Design and operational control methodology for large-scale photovoltaic system in green port application

ABSTRACT Due to the complex-shading and ununiform-corrosion problems caused by the oceanic climate, the working conditions of photovoltaic (PV) system in port are poor. In this study, some effective PV topologies are developed and compared under typical oceanic conditions. In order to improve the output of port PV system, a novel maximum power point tracking (MPPT) method is developed, in which the convolutional neural network (CNN) and bidirectional long short time memory network (BiLSTM) are introduced to forecast the real-time optimal operation point. Finally, the developed topology and MPPT method are verified by a comprehensive set of case studies. Experimental results show that the total-cross-tied (TCT) and gradient (GT) topologies can achieve the best performance. However, by considering the complex structure and higher failure rate due to the large number of joints in TCT topology, the PV arrays installed on the roofs, in the free space of green belt, freight yard and near the seaside are suggested to be connected in GT topology to balance operation efficiency, failure rate and maintenance costs. Moreover, the developed CNN-BiLSTM-based MPPT method and PV topology can effectively work together, and the average forecasting error is just 3.482%, which outperforms the compared state-of-the-art methods significantly.

Rates and Predictors of Structural Valve Degeneration and Failure of Trifecta Bioprosthetic Valve Over a 5-year Follow-up Period: A Single-center Experience.

The Trifecta bioprosthetic valve has been commonly used for surgical aortic valve replacement (SAVR). Multiple studies have been done to define the rate of structural valve degeneration (SVD) and failure (SVF), but the outcomes are still debatable. Therefore, we aim to conduct this single-center study to estimate the rate and predictors of SVD/SVF. This retrospective observational cohort single-center study was conducted between 2014 and 2019 among Trifecta SAVR patients. Data were patient's characteristics collected from electronic medical records at baseline and follow-up (3-5 years). Statistical analysis was performed with a significance level of P ≤ 0.05. A total of 271 eligible patients were identified. Most of our sample were males (57.9%), with a mean age of 71.1 ± 10.6 years. The mean baseline preoperative ejection fraction (EF) was 53.0%, with no change (P = 0.88) in the immediate postoperative EF (53.6%). A most recent follow-up EF revealed a significant increase of EF (55.2%), P = 0.01. Furthermore, there was a significant increase from peak velocity to PVMRE (mean difference [MD] ± standard error of mean (SEM) [0.15 ± 0.04], P < 0.01), an increase in pressure gradient (PGIPE) to PGMRE (MD ± SEM [1.70 ± 0.49], P < 0.01), and a decrease in Doppler velocity index (DVIIPE) to DVIMRE (MD ± SEM [-0.037 ± 0.01], P = 0.01). Regarding the SVF rate, 13 (4.8%) patients had failed valves requiring replacement throughout the study period. Over a 5-year follow-up period, 4.8% had SVF with an SVD of 23.2%, with the majority of SVD not being clinically significant except in six patients. These results corroborate with a previously published study suggesting a bad clinical outcome of Trifecta valve placement.

Research on CNN-LSTM Brake Pad Wear Condition Monitoring Based on GTO Multi-Objective Optimization

As the core component of the automobile braking system, brake pads have a complex structure and high failure rate. Their accurate and effective state monitoring can help to evaluate the safety performance of brake pads and avoid accidents caused by brake failure. The wear process of automobile brake pads is a gradual, nonlinear, and non-stationary time-varying system, and it is difficult to extract its features. Therefore, this paper proposes a CNN-LSTM brake pad wear state monitoring method. This method uses a Convolutional Neural Network (CNN) to complete the deep mining of brake pad wear characteristics and realize data dimensionality reduction, and a Long Short-Term Memory (LSTM) network to capture the time dependence of the brake pad wear sequence, so as to construct the nonlinear mapping relationship between brake pad wear characteristics and brake pad wear values. At the same time, the artificial Gorilla Troops Optimization (GTO) algorithm is used to perform multi-objective optimization of the network structure parameters in the CNN-LSTM model, and its powerful global search ability improves the monitoring effect of the brake pad wear status. The results show that the CNN-LSTM model based on GTO multi-objective optimization can effectively monitor the wear state of brake pads, and its coefficient of determination R2 value is 0.9944, the root mean square error RMSE value is 0.0023, and the mean absolute error MAE value is 0.0017. Compared with the BP model, CNN model, LSTM model, and CNN-LSTM model, the value of the coefficient of determination R2 is the closest to 1, which is increased by 8.29%, 5.52%, 4.47%, 3.30%, respectively, which can more effectively realize the monitoring and intelligent early warning of the brake pad wear state.

Tendon progenitor cells as biological augmentation improve functional gait and reduce scar formation after rotator cuff repair

High rates of structural failure are reported after rotator cuff repairs due to inability to recreate the native enthesis during healing. The development of biological augmentation methods that mitigate scar formation and regenerate the enthesis is still an unmet need. Since neonatal enthesis is capable of regeneration after injury, this study tested whether delivery of neonatal tendon progenitor cells (TPCs) into the adult injured environment can enhance functional and structural supraspinatus enthesis and tendon healing. TPCs were isolated from Ai14 Rosa26-TdTomato mouse Achilles tendons and labeled using adenovirus-Cre. Fifty-two CB57BL/6J mice underwent detachment and acute repair of the supraspinatus tendon and received either a fibrin-only or TPC-fibrin gel. Immunofluorescence analysis was carried out to determine cellularity (DAPI), fibrocartilage (SOX9), macrophages (F4/80), myofibroblasts (α-smooth muscle actin), and scar (laminin). Assays for function (gait and biomechanical testing) and structure (micro-computed tomography imaging, picrosirius red/Alcian Blue staining, type I and III collagen staining) were carried out. Analysis of TdTomato cells after injury showed minimal retention of TPCs by day 7 and day 14, with detected cells localized near the bursa and deltoid rather than the enthesis/tendon. However, TPC delivery led to significantly increased %Sox9+ cells in the enthesis at day 7 after injury and decreased laminin intensity across almost all time points compared to fibrin-only treatment. Similarly, TPC-treated mice showed gait recovery by day 14 (paw area and stride length) and day 28 (stance time), while fibrin-treated mice failed to recover gait parameters. Despite improved gait, biomechanical testing showed no differences between groups. Structural analysis by micro-computed tomography suggests that TPC application improves cortical thickness after surgery compared to fibrin. Superior collagen alignment at the neo-enthesis was also observed in the TPC-augmented group at day 28, but no difference was detected in type I and III collagen intensity. We found that neonatal TPCs improved and restored functional gait by reducing overall scar formation, improving enthesis collagen alignment, and altering bony composition response after supraspinatus tendon repair. TPCs did not appear to integrate into the healing tissue, suggesting improved healing may be due to paracrine effects at early stages. Future work will determine the factors secreted by TPCs to develop translational targets.

Behavior of woven fabric composite under tensile loads in different directions using acoustic emission

The woven fabric composites were used in different industries for their special specification. This study aimed to address failure mechanisms in single-layer woven fabrics. The acoustic emission (AE) technique and wavelet transform were used for composite structural health monitoring and failure rate evaluation. From a mechanical study viewpoint, the load-displacement behavior of plain-woven glass composite was examined under tension in the principal directions (0 and 90°) and off-axis (30, 45, and 60°). The results indicated that off-axis samples are deformed and curled due to the slippage and rotation of warp and weft yarns. The mechanical measurements were synchronized with the AE data in an acousto-mechanical study. The load-displacement behavior of samples was zoned out with two criteria: frequency and energy. Eventually, three failure modes were identified: matrix damage, interface damage, and fiber breakage. The results showed that events with a frequency above 400 kHz at different angles could be attributed to fiber breakage. Also, the applied force angle effectively affects the type of fiber failure (tensile and shear failure). It was found that in addition to tensile failure, shear failure also increases sharply by increasing the angle between the main directions. So that the maximum number of shear fiber failures occurred at the angle of 45° between the main directions. On the off-axis, the number of fibers exposed to the load also increased, increasing the number of breakages.

Follow-up on a Biological Revision Technique for Large, Recurrent, Retracted, Rotator Cuff Tears.

Revision of large recurrent rotator cuff tears by simple repair has a structural failure rate of 40% to 90%. The author presents a minimum 2-year follow-up study of revision rotator cuff reconstructions using a bridging patch graft composed of autogenous biceps tendon saturated with concentrated autologous iliac bone marrow, to determine how the technique compares to the reported outcome of simple repair as a treatment alternative. The principal entrance criterion was a symptomatic rotator cuff retear with retraction creating a 3- to 5-cm defect. Twenty-five consecutive patients (with an average age of 62 years) were enrolled. Twenty-two (88%) were available for follow-up at 24 to 120 months (mean 68 months) for interview and examination. Questionnaires using Constant, American Shoulder and Elbow Surgeons, and University of California at Los Angeles (UCLA) Shoulder scores were completed. In the terminal 15 patients, the presence of viable marrow mesenchymal cells fixed to the tendon graft at the time of implantation was determined by histological verification. Rotator cuff integrity was evaluated by ultrasonography examination. The Wilcoxon rank-sum test was used to compare nonparametric preoperative with postoperative questionnaire outcome scores. Twenty of 22 patients (91%) demonstrated an intact tendon construct. Two of 22 patients (9%) demonstrated structural failure. Viable mesenchymal cells were identified on all graft specimens in high concentration. All patients showed improved results: The mean Constant score increased from 13 to 76; American Shoulder and Elbow Surgeons from 17 to 81; UCLA from 6 to 29 (P < 0.001). The autogenous graft/marrow technique consistently and successfully reconstructed a large, recurrent rotator cuff tear in a clinical setting where the primary cuff repair had failed. The observation that an autogenous tendon graft saturated with concentrated marrow has the biological potential to reconstruct a difficult soft-tissue defect in the shoulder strongly implies its potential as a reconstructive tool for other soft-tissue defects.

Residential code-conforming structural seismic risk maps for Italy

RINTC – Rischio Implicito delle strutture progettate secondo le NTC is an Italian research project aiming at the evaluation of the seismic reliability inherent to design according to the current Italian building code. Within the project, different fixed-base residential and industrial structures typologies, as well as some base-isolated reinforced concrete buildings were addressed. The structures were located in three Italian sites characterized by different levels of seismic hazard. For each designed, modelled, and analyzed building, the seismic reliability, in term of annual failure rate, was computed. Based on these results, the aim of the study discussed in the paper is to derive national seismic risk maps for Italy in an ideal scenario where all the existing (residential) buildings would be code-conforming, either fixed-base or base-isolated. The analyses are performed at the municipality scale, combining the structural fragility functions with alternative models of probabilistic seismic hazard for Italy, and including exposure in terms of typological composition of the existing building stock. Results, presented in the form of maps of structural failure rates, generally show that: (i) despite the same return period of design seismic intensity over the country, failure rates greatly vary with the increasing hazard of the sites (generalizing one of the main outcomes of the RINTC project), (ii) the alternative hazard models produce limited variations of the failure rates, especially when global collapse is considered.

Total quality management (TQM) implementation in the Nigerian construction industry

PurposeLack of strict compliance to the principles of total quality management (TQM) by construction organizations has brought about poor quality of the finished building projects. This has been blamed for the incessant structural failure reported in Nigeria. This study appraised TQM implementation in the Nigerian construction industry, with a view to mitigating structural failure rate of construction projects. To achieve this aim, the study aims to assess the practice level of TQM and the factors hindering TQM implementation on construction projects.Design/methodology/approachThe study utilized a well-structured questionnaire and convenient sampling method in the gathering and sampling of data among construction professionals in Imo state, Nigeria. Data analyses were done using, frequency, percentage, mean analytics and Pareto analysis.FindingsThe study revealed that major practice of TQM principles with respect to structural failure rate are purchasing: ensuring the procurement of materials of the specified quality standard, ensuring the use of a quality improvement construction process of the organization, site management responsibility: this entails ensuring quality supervision by the project management leadership and monitoring and control of quality during the construction to guarantee firm observance quality standards. Also, the major factors hindering TQM implementation on construction projects are: inadequacy of the necessary machineries, equipment, tools and facilities for the effective execution of work on construction site; breakdown in communication and information exchange between the management and supervisory teams on site; poor attitudes and strategies toward maintenance of equipment, tools and machines; and absence of prompt salary and incentive payment. It was recommended that construction firms must require the suppliers of construction materials to strictly comply with quality specification evidence in quality certification of delivered materials to mitigate structural failure.Research limitations/implicationsThis study appraised TQM implementation in the construction industry of Nigeria, with emphasis on Imo state. The study underscores the practice level of TQM and the key factors hindering TQM implementation on construction projects. Following the localized geographical limitation of the study area, a similar research in other part/states of Nigeria or even in other developing countries of African is necessary.Practical implicationsThe practices level of TQM and the factors hindering TQM implementation were identified. This will be useful in guiding construction firms, other industry's key stakeholders and regulatory agencies in bringing about a sustainable quality management system for improve profit and value maximization and avoiding incessant structural failure.Originality/valueThis is one of the few studies that have assessed the practice level of TQM and the factors hindering TQM implementation on construction projects in Nigeria. This study took place in Imo state with records of periodic structural failure and building collapse.

Long-term echocardiographic findings after TAVR: 5-year follow-up in 400 consecutive patients

A little is known about long-term hemodynamic performance of the transcatheter heart valves (THVs). The aim of the present study was to assess hemodynamic outcome, structural valve deterioration (SVD) and bioprosthetic valve failure (BVF) in patients treated with transcatheter aortic valve replacement (TAVR) five or more years ago. All consecutive patients treated at Bologna and Florence University Hospitals with TAVR between January 2008 and December 2013 were analyzed in a retrospective registry with regards to demographic, procedural and outcome data as well as follow-up data on mortality and echocardiographic characteristics. Standardized definitions were used to define outcomes and durability of the THVs. 400 patients were included in the study, mostly treated with transfemoral TAVR (71.8%), using first generation balloon-expandable (37%) or self-expanding (63%) devices. The 1-year mortality was 21.8% (87 patients) and 5-year mortality was 53.8% (215 patients). Median follow-up was 45.5months (14.0-68.9) totaling 1516.7 patient/years, with the longest follow-up being 10.25years. At least one follow-up echocardiogram was available for 320 patients (80%), SVD occurred in 19 of these patients (5.94%): moderate in 17 patients (5.31%) and severe in two patients (0.63%). The hemodynamic presentation was stenosis in most of the cases (12 patients). Late BVF was registered in 10 patients (3.13%) and this was mainly driven by transcatheter paravalvular leak closure (six patients) with subsequent good long-term outcome. Our results confirm that TAVR appears to be a long-lasting treatment strategy with low rates of structural valve degeneration and valve failure.

The Rheometric Analysis of the Polymer Modifier's Properties in the Environment of Hydrated Cement.

This paper investigates the effect of polymer modifiers (re-dispersible powder, multifunctional additives, methylhydroxyethylcellulose) on the rheological behavior of emulsions, saturated of calcium hydrosilicates to simulate a hydrating cement structure. The subjects of the study were modified emulsions which had varied concentrations of each additive and they were examined comparatively to a base emulsion. Tests were performed with a CR-rheometer (“Himpribor-1”, Tula, Russia) applying the Searle measuring principle at various shear rates to characterize viscosity properties. The performance of modified mixtures within the operating period was analyzed by using two parameters—effective viscosity (η) and the proportion of structural failure (|m|). The test results showed that the most important factor influencing rheological characteristics is the addition of methylhydroxyethylcellulose additive—the higher additive amount in the emulsion, the higher the viscosity. Furthermore it was noted in the work that adding olefin sulfonate sodium salt causes reduced viscosities as well as lower shear moduli. If ethylhydroxyethylcellulose and ethylene vinyl acetate additives are used in the same mixture together, the rate of structural failure |m| can be relatively similar and low regardless of whether the mixture has large or small viscosity values.

Clinical outcomes and structural integrity rate of arthroscopic augmented rotator cuff repairs using extracellular porcine matrix patch.

Structural failure rate in rotator cuff repairs is still high. The purpose of the study is to assess the structural integrity of a series of augmented rotator cuff repairs with porcine matrix patch and report the functional outcomes. Between 2014 and 2017, 44 consecutive patients underwent arthroscopic double-row repair of medium to massive rotator cuff tears with extracellular porcine dermal matrix augmentation. At one-year follow-up, magnetic resonance imaging scan was performed to assess the integrity of the repair. Oxford Shoulder Score (OSS), Constant Score (CS) and Visual Analogue Scale pain score, together with range of motion were used to assess patients. Patients mean age was 68 (53-82); mean follow-up was 17.2 (12-24) months. On magnetic resonance imaging scans, seven rotator cuff repair failures (15.9%) were observed: tear size was an independent predictor of re-rupture at one-year follow-up. Clinical scores showed a statistically significant improvement at three months and until final follow-up (p< 0.001). No complications occurred. Observed structural failure rate of 15.9% is lower than those reported in the literature for standard rotator cuff repair of medium to massive tears in similar cohorts to ours. Extracellular matrix augmentation for rotator cuff repair was shown to be a safe and reliable support to the repairs and patients recovered good shoulder function.Level of Evidence: Level IV.

How Many Proximal Screws Are Needed for a Stable Proximal Humerus Fracture Fixation?

Purpose:This biomechanical study investigates the optimal number of proximal screws for stable fixation of a 2-part proximal humerus fracture model with a locking plate.Methods:Twenty-four proximal humerus fracture models were included in the study. An unstable 2-part fracture was created and fixed by a locking plate. Cyclic loading and load-to-failure tests were used for the following 4 groups based on the number of screws used: 4-screw, 6-screw, 7-screw, and 9-screw groups. Interfragmentary gaps were measured following cyclic loading and compared. Consequently, the load to failure, maximum displacement, stiffness, and mode of failure at failure point were compared.Results:The interfragmentary gaps for the 4-screw, 6-screw, 7-screw, and 9-screw groups were significantly reduced by 0.24 ± 0.09 mm, 0.08 ± 0.06 mm, 0.05 ± 0.01 mm, and 0.03 ± 0.01 mm following 1000 cyclic loading, respectively. The loads to failure were significantly different between the groups with the 7-screw group showing the highest load to failure. The stiffness of the 7-screw group was superior compared with the 6-screw, 9-screw, and 4-screw groups. The maximum displacement before failure showed a significant difference between the comparative groups with the 4-screw group having the lowest value. The 7-screw group had the least structural failure rate (33.3%).Conclusion:At least 7 screws would be optimal for proximal fragment fixation of proximal humerus fractures with medial comminution to minimize secondary varus collapse or fixation failure.Level of Evidence:Basic science study.

Humeral stress shielding following cemented endoprosthetic reconstruction: An under-reported complication?

The proximal humerus is a common location for primary and non-primary tumors. Reconstruction of the proximal humerus is commonly performed with an endoprosthesis with low rates of structural failure. The incidence and risk factors for stress shielding are under reported. Thirty-nine (19 male, 20 female) patients underwent resection of the proximal humerus and reconstruction with a cemented modular endoprosthesis between 2000 and 2018. The mean resection length was 12 ± 4 cm and was most commonly performed for metastatic disease (n = 26, 67%). Stress shielding was observed in 9 (23%) patients at a mean of 29 (6-132) months postoperatively. Patients with stress shielding were noted to have shorter intramedullary stem length (87 vs. 107 mm, p < .001), longer extramedullary implant length (16 vs. 14 cm, p = .01) and a higher extramedullary implant to stem length ratio (2.1 vs. 1.1, p < .001). The incidence of stress shielding was higher (p = .003) in patients reconstructed with 75 mm stem (n = 6, 67%) lengths. Stress shielding of the humerus was associated with the use of shorter stems and long extramedullary implants. The long-term ramifications of stress shielding on implant stability, complications at the time of revision surgery, and overall patient outcomes remain unknown.

Optimal load factors for earthquake-resistant design of buildings located at different types of soils

This paper addresses the influence of the local soil type (firm or soft) on the reliability-based optimal load combination factors for seismic design of buildings. The approach aims to minimize the total expected life-cycle cost (LCC) of a structure. As a constraint, it is established that the mean annual rate of structural failure should be less than or equal to a certain prescribed value. The LCC of the structure includes 1) initial cost, 2) cost due to damages, and 3) social costs. The methodology is applied for two sets of reinforced concrete buildings; the first set is located on firm ground and the second on soft soil. The reinforced concrete buildings are designed using different load combination factors, and the total expected cost is estimated for each set of buildings. It is concluded that the optimal load combination factors for the buildings on soft soil are different from that obtained on firm ground. Finally, some recommendations are provided to estimate the seismic load factors for structures located at firm and soft soils.

Effects of frame beam on structural characteristics of artificial soil on railway cut‐slopes in southwestern China

AbstractCut‐slope restoration technologies commonly used in southwest China mainly include using simple outside soil spray seeding (OSSS) techniques, or OSSS combined with an anchor frame beam. Artificial soil used in OSSS can establish a soil layer suitable for revegetation; the addition of an anchor frame beam not only fixes soil and shallow rock, it also acts to strengthen deep rock. However, there have been few studies on the effects of frame beams on artificial soil structural characteristics on railway cut‐slopes. In order to evaluate the effects of different frame beams on artificial soil structure, soil samples from a natural slope (NS) and three cut‐slopes restored using OSSS with various frame beams (AS, arched slope; DS, diamond slope; and RS, rimless slope) were analyzed. Soil structural characteristics analyzed include particle‐size percentage and cumulative distribution curve of dry‐sieving and wet‐sieving aggregates, structural failure rate, water stability factor, soil particle size distribution (PSD), bias and peak convex coefficients, fractal dimension of PSD (Dm), and fundamental properties. Our results indicate that structural failure rate, water stability factor, fractal dimension of PSD, soil bulk density, total porosity, moisture content, and organic matter are significantly affected by the use of different frame beams. In addition, a difference in wet‐sieving soil aggregates content, PSD, clay and sand particle contents, Dm, and the area difference ΔS of cumulative distribution between AS and DS was evident. Overall, soil structure in cut‐slopes using a diamond frame anchor beam recorded the best levels of recovery after 8 years of ecological restoration.

Ten year follow-up of high-risk patients treated during the early experience with transcatheter aortic valve replacement.

The long-term clinical performance of transcatheter heart valves (THV) is unknown. This study assessed the clinical outcomes, rate of structural valve deterioration (SVD) and bioprosthetic valve failure in patients after transcatheter aortic valve replacement (TAVR) to 10-year follow-up. Consecutive patients undergoing TAVI for native aortic valve stenosis or failed aortic surgical bioprosthesis, between 2005 and 2009 at our institution were included. A total of 235 consecutive patients. At the time of TAVI mean age was 82.4 ± 7.9 years. All patients were judged to be high risk, with a STS score > 8 in 53.6%. THVs implanted were the Cribier-Edwards (20.9%), Edwards SAPIEN (77.4%) or CoreValve (1.7%). Mortality at 1, 5, and 10-year follow-up was 23.4%, 63%, and 91.6%, respectively. Of the total cohort, 15 patients had structural valve deterioration/bioprosthetic valve failure, with a cumulative incidence at 10-years of 6.5% (95% CI 3.3%, 9.6%). The rate of SVD/BVF at 4, 6, 8, and 10 years was 0.4%, 1.7%, 4.7%, and 6.5%, respectively. Nine patients had moderate SVD and six patients had severe SVD. Of the six patients with severe SVD, two patients had reintervention (one patient had redo TAVR, and the second had surgical aortic valve replacement). Survivors (n = 19) at 10-year follow-up, had a mean gradient of 14.0 ± 7.6 mmHg and aortic regurgitation ≥moderate in 5%. Quality of life measures in 10-year survivors demonstrated ADLs 6/6 in 43.8%, and ambulation without a mobility aid of 62.5%. Using early generation balloon expandable THVs in a high-risk population, there was a low rate of structural valve deterioration and valve failure at 10-year follow-up. This study provides insights into the long-term performance of transcatheter heart valves and patients self-reported derived benefits.

A full factorial experimental design to study the effect of flavoring agents on the mechanical properties of curcumin chewing gum tablets with high solids content

Objective: Developing chewing gum tablets (CGTs) with high drug loads is a challenge due to the loss of mastication properties. We postulated that poor mastication properties of such gums could be improved by adjusting the concentration of liquid flavors to serve as plasticizers and consequently increase the flexibility of the elastomer in the gum base. To test this hypothesis, the objective of this work was to evaluate the effects of flavor type and concentration, and storage conditions on the textural properties of CGTs loaded with 20% curcumin (CUR) by weight.Methods: CGTs were made by directly compressing Health in Gum® base with CUR. The resultant CGTs were characterized by single and two bites textural tests to measure their yield strength, post-bite failure rate, and compressibility.Results: Flavor concentration (X2) had a significant impact on the masticatory properties of the chewing gums, which could be ascribed to the plasticizing effect of peppermint oil. Addition of liquid flavors and storage at low temperature (X4) produced CGTs with the desirable properties of low yield strength (Y1) and post-bite structural failure rate (Y2), and high compressibility (Y3). The effect of flavors however was negated at high temperatures, especially when flavored gums were stored for extended time at 50 °C. Flavor type (X1) on the other hand had no effect on the masticatory properties of the chewing gums.Conclusions: This study concluded that it is feasible to formulate CGTs with high solids content without negatively impacting their mechanical properties by controlling the concentration of liquid flavors.

Artificial soil nutrient, aggregate stability and soil quality index of restored cut slopes along altitude gradient in southwest China.

In the subalpine mountainous region of southwest China, the artificial soil properties of restored cut slopes along the altitude gradient were studied, including available nitrogen (AN), available phosphorus (AP), available potassium (AK), urease (UR), sucrase (SC), protease (PR), catalase (CAT), texture, and aggregate stability of soil. Soil aggregatet stability by mean weight diameter (MWD), geometric mean diameter (GMD), structure failure rate (P), index of unstable aggregates (IUA) and area difference of dry and wet sieve cumulative distribution curve (ΔS) were measured and analyzed. It was found that available soil nutrients, UR, and CAT activities increased initially and then decreased, but the texture of soil was finer, and aggregate structure tended to be more stable along with an increase in the altitude gradient. The soil aggregate stability index that MWD, GMD, P, IUA, and ΔS indicated that the higher the altitude, the stability of soil aggregates was better. Principal component analysis (PCA) was used to determine the soil quality index (SQI). The obtained results from this study showed that the artificial soil quality of the cut slopes was better at a higher altitude compared to a lower altitude. These results provide a reference for the improvement of artificial soil properties of cut slopes and their quality in the future. It is necessary to pay attention to the soil quality management at a low-altitude area and reform the soil nutrients, enzyme activities, and soil structure for the restored cut slopes in the mountainous subalpine highway of southwest China.