Stability Measurements Research Articles

In situ/operando method for energy stability measurement of synchrotron radiation.

A novel in situ/operando method is introduced to measure the photon beam stability of synchrotron radiation based on orthogonal diffraction imaging of a Laue crystal/analyzer, which can decouple the energy/wavelength and Bragg angle of the photon beam using the dispersion effect in the diffraction process. The method was used to measure the energy jitter and drift of the photon beam on BL09B and BL16U at the Shanghai Synchrotron Radiation Facility. The experimental results show that this method can provide a fast way to measure the beam stability of different light sources including bending magnet and undulator with meV-level energy resolution and ms-level time response.

Developing high-performance oxygen electrodes for intermediate solid oxide cells (SOC) prepared by Ce0.8Gd0.2O2−δ backbone infiltration

Gd0.2Ce0.8O 2−δ (GDC) porous backbone infiltration with La0.6Sr0.4CoO3−δ (LSC), PrOx and LSC: PrOx as a composite oxygen electrode for intermediate solid oxide cells are conducted within the scope of this work. Samples were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and electrochemical impedance spectroscopy (EIS). A uniform distribution of the infiltrated material inside the backbone and at the electrolyte-backbone interface was achieved. EIS measurements on the prepared symmetrical samples showed electrode polarization resistance (Rp) values of 0.029 Ω.cm², 0.23 Ω.cm², and 0.44 Ω.cm² for LSC, LSC: PrOx, and PrOx at 600 °C, respectively. Long-term stability measurements at 600 °C for 100 h showed a slight increase in polarization resistance during the measurement period. Fuel cell measurements of commercial cells (Elcogen) with porous oxygen electrode consisting of GDC infiltrated with LSC showed an increase in power density compared to the reference cell with a value of 0.53 W.cm− 2 obtained at 600 °C. It is proven that infiltration via polymeric precursor into porous scaffolds as backbone oxygen electrode layer is effective and convenient method to develop high performance and stable solid oxide cells.

The impact of fatigue on dynamic balance in coopers athletes with chronic ankle instability

Athletes who have successfully regained high sports performance despite prior inversion injuries, and who do not have persistent symptoms, are referred to as “copers” in the literature. The aim of the study was to assess dynamic stability under fatigue in patients with chronic ankle instability in comparison to healthy controls. We conducted a case - controlled study on a group of 60 young, physically active individuals aged 29.8 ± 4.6. They were divided into 3 groups: I - unilateral ankle instability n = 14, II - bilateral ankle instability n = 15, III - no ankle instability, n = 31. All participants filled out questionnaires on the health, the FADI and FADI-S. The study protocol consisted of a dynamic stability measurements by Biodex Balance System, followed by a fatigue test, followed by the series of the same measurements. General stability index value before and value after fatigue test did not differ significantly. The differences between groups in measurements taken before fatigue test (F (2.49) = 1.59; p = 0.214; ηp2 = 0.06) and after fatigue test also proved insignificant (F (2.49) = 1.28; p = 0.286; ηp2 = 0.05). The incidence of structural ankle instability did not affect functional stability. “Copers” had efficient neural-muscular control in dynamic stabilography tests.

Primary ACL repair in a selected patient cohort: A prospective single cohort study

BackgroundAnterior cruciate ligament (ACL) tears are common knee injuries, particularly in physically active individuals. While ACL reconstruction (ACL-R) is the standard treatment, it has notable limitations. Recent interest in primary ACL repair offers a potential alternative, especially for specific tear types and patient demographics. PurposeTo evaluate the outcomes of primary ACL repair in a selected patient cohort with strict inclusion and exclusion criteria, focusing on the survival of the procedure, functional outcomes, and factors influencing success rates. MethodsThis prospective single cohort study included 61 patients who underwent primary ACL repair between June 2016 and June 2022. Patients were 50 years or younger, with recent ACL injuries and no previous knee surgeries or multiligament injuries. The primary outcomes were the survival of the repair beyond two years, measured by revision rates, and functional outcomes assessed using the Lysholm knee score, Tegner activity scale, and Lachmeter stability measurements. ResultsFifty-four patients completed a minimum follow-up of three years (average 49.6 months). The overall success rate was 82.2 %, with Sherman type 1 tears showing significantly fewer failures compared to type 2 (4.3 % vs. 31.8 %). The mean Lysholm score for successful repairs was 96, and the Tegner score dropped from a pre-injury average of 6 to 5. Adolescents had the highest failure rate (50 %), while other age groups showed better outcomes. The mean side-to-side difference in stability was 1.4 mm, favoring the control side. ConclusionPrimary ACL repair is a viable option for selected patients, particularly those with Sherman type 1 tears. While age and tear type significantly affect outcomes, the procedure shows promising results with high functional scores in successful repairs. Further research with larger cohorts and extended follow-ups is necessary to validate these findings and refine patient selection criteria. Primary ACL repair offers a less invasive alternative to ACL reconstruction, with potential for comparable outcome.

Designing of a High Performance NiMgPO4/CNT Electrode Material for a Battery-Supercapacitor Hybrid Device

Improved pseudo-capacitance performance can be obtained by phosphates and transition-metal oxides by achieving oxidation states that boost redox (reduction-oxidation) processes. In this work, the nickel magnesium phosphate (NiMgPO4) is synthesized using the hydrothermal method, Additional, carbon nanotubes (CNTs) are blended with NiMgPO4. To build the supercapattery device (NiMgPO4@CNT//AC) and evaluate its electrochemical characteristics, we used NiMgPO4@CNT as the anode & activated carbon as cathode. We also used X-ray diffraction, scanning electron micrscopy, Brunauer–Emmett–Teller, and X-ray photoelectron spectroscopy techniques to analyze the crystal structure, surface area, and elemental composition. The nanocomposite NiMgPO4@CNT demonstrated a high specific capacity of 1243 C g−1 or 2071.66 F g−1 in a three-electrode system, which was much more than that of the separate reference materials. The supercapattery device shows a specific capacity of 251 C g−1, energy density of 44.5 Wh kg−1 and power density of 1030 W kg−1 is observed. The hybrid electrode exhibited a capacity retention of 85% after 5000 cycles and a columbic efficiency of 91% during the stability measurement. These findings emphasize NiMgPO4@CNT’s potential as an electrode composite material that holds promise for high-performance supercapattery device building.

Soil aggregate stability index independent from pre-stress aggregate size distribution: A test from soils affected by the water level fluctuation in the Three Gorges Reservoir, China

Soil aggregate stability measurement is essential to determine soil health status under various conditions. The Mean Weight Diameter (MWD) is the most applied index to express aggregate stability particularly for wet and dry sieving. However, the MWD could generally present results affected by pre-stress aggregate size distribution when remained aggregates after stress are considered for calculation. Therefore, the objective of the present study was to eliminate the similarities between the MWD results and pre-stress aggregate size distribution, which largely affects treatments differentiation. Samples from 145-160 m (lower), 160–169 m (middle), and 169–175 m (upper) elevations differently affected by the Water Level Fluctuation in Three Gorges Reservoir (TGR) and control (>175 m) were exposed to wet shaking stress. Aggregates remained at each sieve opening, aggregates disintegrated/passed through the sieve opening, and small macroaggregates and microaggregates accumulated were recorded. These aggregates were used to determine and compare two indexes (1) using remained aggregates (MWD) and (2) using disintegrated/accumulated aggregates (MWDd/a) based on the differences among treatments. The results for both pre-stress aggregates and remained aggregates after stress were showed consistent significant differences (p < 0.05) between upper and control elevations. This gives indication that aggregates remained after stress strongly depend on pre-stress aggregate size distribution. As the MWD was calculated from remained aggregates, the identified difference between upper and control elevations for this index could also confirm its dependence to pre-stress aggregates distribution. Contrary, disintegrated and accumulated aggregates showed non-significant differences between upper and control elevations. This non-significant and significant differences between upper and control elevations for disintegrated and pre-stress aggregates suggest a non-dependence condition. Similarly, the upper and control elevations showed no significant differences in MWDd/a. This substantially informs that this index is independent from pre-stress aggregates distribution because it was entirely calculated from disintegrated aggregates. Higher aggregate stability was indicated by high MWD, with values ranging from 1.41 to 6.24 mm. On the other hand, higher stability was expressed by lower values of the MWDd/a, with the values varying between 3.87 and 0.5 mm. Overall, the present study evidenced the major advantage of considering the disintegrated/accumulated than remained aggregates in calculating unbiased MWD index for aggregate stability.

New biologically active sulfonamides as potential drugs for Alzheimer's disease.

A family of new compounds with sulfonamide and amide functional groups as potential Alzheimer's disease drugs were prepared by multistep synthesis. Thermal stability measurements recorded the initial decomposition in the range of 200-220°C, close above the melting point. The final compounds were tested for their ability to inhibit acetylcholinesterase and butyrylcholinesterase, and the in vitro dissolution behavior of selected compounds was studied through both lipophilic and hydrophilic matrix tablets. All nine tested derivatives were even more active in inhibiting acetylcholinesterase than the clinically used rivastigmine. Regression analysis of the obtained dissolution profiles was performed, and the effects of the pH and the release mechanism were determined. Some substances showed remarkable biological activity and became a subject of interest for further extensive study.

Utilizing Environmentally and Recycled Materials to Formulate Drilling Mud

It is important to pay attention to environmental regulations while preparing drilling mud because it has become aspects that must be taken into consideration both now and in the future. It is essential to use sustainable and environmentally friendly materials at every stage of the oil and gas industry if possible in order to ensure high standards of sustainable practices. Oil that has been used to prepare oil base mud have bad impact on soil and human at the same time. The using of flaxseed oil instead of gas oil to preparing emulsion is done in this paper. The results were encouraging, and showed the possibility of using flaxseed oil for preparing ecological emulsion. The efficacy of walnut shell powder as an emulsifying agent has been tested as a surface tension reducer and the possibility of using it to increase the stability of an oil emulsion either in reverse or direct at high temperatures (400°F). This research includes measurements of filtration, stability and rheological properties of oil emulsion under laboratory and high temperature. Sample C showed high stability less than 3% because it is a direct emulsion composed of 10% flaxseed oil and crushed walnut shells, which acted as an excellent emulsifying agent because it was composed of cellulose with a percentage of more than 40%. Sample E gave the highest viscosity values, and the reason for this is that it is a reverse emulsion consisting of 60% flax oil with a high viscosity, as it reached more than 70 centipoises at 400 degrees Fahrenheit.

Novel AIE and solvatochromism exhibiting TPE based organic fluorophore with excellent emission properties in solid and solution phase for latent fingerprint and metronidazole sensing in real samples

Organic molecules with extended aromaticity are important when designing probes with optical properties. Herein, we designed and synthesized a novel tetraphenylethylene (TPE) based organic molecule TC exhibiting excellent photophysical characteristics. A thorough and in-depth study of the optical properties of probe TC was performed including solvatochromism, aggregation and solid-state studies using ultraviolet–visible (UV Vis) and fluorescence spectroscopy. Also, its optical properties under a UV 365 nm laser were investigated. The compound exhibited aggregation induced emission (AIE) which was thoroughly investigated in a H2O/DMF system and later utilized in formulation of invisible ink and latent fingerprint sensing. Moreover, the excellent emission properties of probe TC were utilized for the highly selective detection of the antibiotic metronidazole (MET) in real samples including human serum and artificial urine. Furthermore, portable TLC and paper-based strips were designed for the on-site detection of MET. Additionally, the mechanism of selective sensing of MET was thoroughly investigated through spectroscopic studies including titration NMR, fluorescence, UV Vis studies and DFT studies. Photoinduced electron transfer (PET) was attributed as the plausible sensing mechanism for the detection of MET. Scanning electron microscopy (SEM) also supported the sensing of MET through change in morphology. DFT calculations involved the measurement of thermodynamic stability, reduced density gradient (RDG) analysis, molecular orbital, and charge transfer studies as well as analysis of quantum theory of atoms in molecules (QTAIM). All the studies supported the presence of non-covalent interactions between probe TC and MET.

Determination of hepatitis B virus (HBV) DNA in serum by nucleic acid screening

The determination of serum hepatitis B Virus (HBV) DNA is of paramount significance in the comprehensive management of HBV infection. It aids in diagnosis, disease staging, and treatment monitoring, ultimately improving patient outcomes and reducing the burden of HBV-related morbidity and mortality. In this work, serum HBV DNA detection was performed using a novel nucleic acid screening system. The sensitivity, selectivity, repeatability, cross reactivity, and HBV DNA stability were evaluated and compared with published data. The detection limit of 95% was 29.12 IU/mL and the 95% confidence interval was from 23.71 to 34.55 IU/mL. Blood samples that contain free hemoglobin (1 g/L, 2 g/L, 4 g/L) and triglycerides (3 mmol/L, 6 mmol/L and 9 mmol/L) were also analyzed. The results demonstrated that the system can also be used in the presence of free hemoglobin and triglycerides. The mean of the cycle threshold (Ct) in 5-day replicates was 35.71 ± 0.35 with a coefficient of variation (CV) of 0.97%. The results of negative samples in the anti-cross contamination experiment showed no response. The coincidence rate for 3001 samples over 20 days of real-time stability measurements and external quality assessment samples was 100%. The results demonstrate the effectiveness of the nucleic acid system for HBV-DNA, providing a theoretical basis for other small and medium-sized blood stations or hospitals to these devices.

Construction of Cyclodextrin-Based Covalent Organic Frameworks for Efficient Encapsulation of Menthol.

The application of flavoring ingredients like menthol in the food industry is hindered by their high volatility and poor thermal stability, which lead to significant losses during processing and storage. Encapsulation of flavors into porous materials to obtain inclusion complexes (ICs) has proved to be an efficient strategy. In the present study, we synthesized a series of relatively food-safe three-dimensional anionic cyclodextrin-based covalent organic frameworks (CD-COFs) with spiroborate linkages using a facile microwave-assisted method. The high surface area and newly formed cavitied of COFs significantly enhanced the encapsulation efficiency of menthol compared to native CD materials. Our findings revealed that γ-CD-COF-Li, with Li+ as the counterion, achieved superior encapsulation efficiency of 25.9%, outperforming γ-CD-COF-Na, γ-CD-COF-K and α-CD-COF-Li under the same conditions. Thermal stability measurements show that the menthol/γ-CD-COF-Li-ICs effectively stabilize menthol against heat evaporation at elevated temperatures due to the strengthened interaction between menthol and γ-CD-COF-Li. The promising results of this research suggest that rapid advancements in COF technology will provide new opportunities for enhancing the stability of flavoring ingredients in the food industry.

Defining the exit meta-analysis.

In recent decades, clinical research has seen significant advancements, both in the generation and synthesis of evidence through meta-analyses. Despite these methodological advancements, there is a growing concern about the accumulation of repetitive and redundant literature, potentially contributing to research waste. This highlights the necessity for a mechanism to determine when a meta-analysis has conclusively addressed a research question, signaling no further need for additional studies-a concept we term an "exit" meta-analysis. We introduced a convergence index, the Doi-Abdulmajeed Trial Stability (DAts) index, and a convergence plot to determine the exit status of a meta-analysis. The performance of DAts was examined through simulation and applied to two real-world meta-analyses. The DAts index and convergence plot demonstrate highly effective discriminative ability across varying study scenarios. This represents the first attempt to define an exit meta-analysis using a quantitative measurement of stability (as opposed to sufficiency) and its corresponding plot. The application to real-world scenarios further validated the utility of DAts and the convergence plot in identifying a conclusive (exit) meta-analyses. The new development of DAts and the convergence plot provide a promising tool for investigating the conclusiveness of meta-analyses. By identifying an exit status for meta-analysis, the scientific community may be equipped to make better-informed decisions on the continuation of research on a specific topic, thereby preventing research waste and focusing efforts on areas with unresolved questions.

Plane mirror-optical path coupling noise in telescope off-axis system dimensional stability measurement

The dimensional stability of the off-axis optical system affects its optical performance significantly and may even lead to its failure. Here, we report a heterodyne interferometry technology to measure the telescope’s dimensional stability. In this method, the standard plane mirror, which reflects the measurement laser, is a critical structural component. Additionally, it is one of the primary sources of the noise. The study focuses on the impact of the standard plane mirror’s positional misalignment instability on optical path noise. A mathematical model was established to depict the effects of mirror misalignment instability on the optical path, and experiments were conducted to decouple the noise. The results of the experiment show that the standard plane mirror introduces approximately 1nm/Hz1/2 at 10 mHz of optical path noise into the off-axis system, and the dimensional stability of the off-axis system is about 6.23nm/Hz1/2 at 10 mHz.

Sub-attosecond-precision optical-waveform stability measurements using electro-optic sampling

The generation of laser pulses with controlled optical waveforms, and their measurement, lie at the heart of both time-domain and frequency-domain precision metrology. Here, we obtain mid-infrared waves via intra-pulse difference-frequency generation (IPDFG) driven by 16-femtosecond near-infrared pulses, and characterise the jitter of sub-cycle fractions of these waves relative to the gate pulses using electro-optic sampling (EOS). We demonstrate sub-attosecond temporal jitter at individual zero-crossings and sub-0.1%-level relative amplitude fluctuations in the 10-kHz–0.625-MHz band. Chirping the nearly-octave-spanning mid-infrared pulses uncovers wavelength-dependent attosecond-scale waveform jitter. Our study validates EOS as a broadband (both in the radio-frequency and the optical domains), highly sensitive measurement technique for the jitter dynamics of optical waveforms. This sensitivity reveals outstanding stability of the waveforms obtained via IPDFG and EOS, directly benefiting precision measurements including linear and nonlinear (infrared) field-resolved spectroscopy. Furthermore, these results form the basis toward EOS-based active waveform stabilisation and sub-attosecond multi-oscillator synchronisation/delay tracking.

Posture, balance and gait in axial spondyloarthritis: a case-control study.

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease that primarily involves the axial skeleton but may also present with peripheral joint involvement and extra-articular involvement. The present study aims to quantitatively analyze posture, balance, and gait parameters in patients with axSpA and and assess associated factors. This cross-sectional case-control study included 51 axSpA patients (30 males, 21 females; mean age 40.94 ± 10.48 years) and 51 age- and sex-matched healthy controls. In patients with axSpA, the Ankylosing Spondylitis Disease Activity Score CRP, the Bath Ankylosing Spondylitis Disease Activity Index(BASDAI), the Bath Ankylosing Spondylitis Functional Index (BASFI), the Bath Ankylosing Spondylitis Metrology Index(BASMI), the Maastrich Ankylosing Spondylitis Enthesitis Score(MASES), and the Ankylosing Spondylitis Quality of Life(ASQoL) scale were used. For postural analysis, DIERS formetric (Diers GmbH, Schlangenbad, Germany) videoraster- stereography device was utilized. HUR SmartBalance BTG4 (HUR-labs Oy, Kokkola, Finland) balance platform was used for postural balance and limit of stability (LOS) measurement. Participants were evaluated using Berg Balance Scale (BBS), Functional Reach Test (FRT) and Timed Up and Go Test (TUG). The Zebris FDM type 3 (Zebris Medical GmbH, Germany) walking platform was used to measure the spatiotemporal parameters of the participants. Comparison of postural parameters showed that sagittal imbalance and cervical depth distance were increased in the axSpA group than in the healthy participants (p < 0.004). Comparison of functional balance parameters showed that BBS and FRT scores were significantly lower (p < 0.001) in the axSpA group than in the control group, while TUG scores were significantly higher (p < 0.001). The LOS values, which evaluate dynamic balance were significantly lower, indicating impairment, in the axSpA group. In the measurement of postural sway, which indicates static balance, all 23 subparameters were found to be similar. When analyzing the spatiotemporal gait parameters, in the axSpA group compared with those in the control group; Foot angles (p= 0.028) and stride width (p = 0.004) were increased, whereas step lengths (p = 0.004) and stride lengths (P = 0.004) were decreased. In the axSpA group the gait speed was decreased (p = 0.004). When axSpA was analyzed separately as radiographic and nonradiographic axSpA, similar findings were observed in posture, balance, and gait parameters. No significant difference was observed. We found that the clinical assessments most closely associated with posture, balance, and gait analyses were BBS, FRT, TUG, and BASFI.

Hypersonic Stability and Breakdown Measurements on the AFRL/AFOSR BOLT II Flight Geometry

The Air Force Research Laboratory/Air Force Office of Scientific Research (AFRL/AFOSR) introduced the Boundary Layer Turbulence (BOLT II) flight experiment to further the understanding and modeling of a hypersonic turbulent boundary layer on a geometry that features concave surfaces with swept leading edges. In support of the flight experiment, this paper identifies and documents the transition instabilities and quantifies the breakdown to turbulence on a 25%-scale BOLT II model in hypersonic flow. Experiments were conducted in the conventional Actively Controlled Expansion wind tunnel facility and the Mach 6 Quiet Tunnel located at the Texas A&M University National Aerothermochemistry and Hypersonics Laboratory. Global surface heating was viewed using infrared thermography with on-surface measurements made using high-frequency Kulite and PCB Piezotronics surface pressure transducers. Modal growth was observed among the sensors both upstream and downstream of the model. Off-surface measurements were made in the mixed-mode region utilizing constant-temperature hot-film anemometry in the Mach 6 Quiet Tunnel. Comparisons were made to the Direct Numerical Simulation (DNS) results from the University of Minnesota. Amplified content was observed between f=53 and 75 kHz in the root-mean-square voltage fluctuations of the hot-film measurements.

Towards the 10-Year Milestone of Monolithic Perovskite/Silicon Tandem Solar Cells.

The perovskite/silicon tandem solar cell represents one of the most promising avenues for exceeding the Shockley-Queisser limit for single-junction solar cells at a reasonable cost. Remarkably, its efficiency has rapidly increased from 13.7% in 2015 to 34.6% in 2024. Despite the significant research efforts dedicated to this topic, the "secret" to achieving high-performance perovskite/silicon tandem solar cells seems to be confined to a few research groups. Additionally, the discrepancies in preparation and characterization between single-junction and tandem solar cells continue to impede the transition from efficient single-junction to efficient tandem solar cells. This review first revisits the key milestones in the development of monolithic perovskite/silicon tandem solar cells over the past decade. Then, a comprehensive analysis of the background, advancements, and challenges in perovskite/silicon tandem solar cells is provided, following the sequence of the tandem fabrication process. The progress and limitations of the prevalent stability measurements for tandem devices are also discussed. Finally, a roadmap for designing efficient, scalable, and stable perovskite/silicon tandem solar cells is outlined. This review takes the growth history into consideration while charting the future course of perovskite/silicon tandem research.

NiFe-Prussian blue analogs catalyst for glucose electrolytic hydrogen production and biomass valorization

Making green hydrogen from natural biomass glucose electrolysis represents a successful win-win scenario which not only achieves energy-efficient hydrogen production but also yields high-value-added chemicals. Herein, we report a NiFe-PBA catalyst synthesized by a facile co-precipitation method for glucose electrooxidation reaction (GOR). Benefiting from the unique ligand structure and the optimal electron, the Ni1·6Fe-PBA achieves a current density of 50 mA cm⁻2 at a potential of only 1.42 V versus Reversible Hydrogen Electrode (RHE), and it maintains potential stability for 50 h. Through an intermittent multipotential-step method it was known that NiOOH is the active site of GOR. Based on the superior GOR activity of this catalyst, we constructed a two-electrode glucose electrolysis hydrogen making system. At a current density of 50 mA cm⁻2, this system reduced the voltage of 230 mV compared to traditional water electrolysis. This improvement significantly reduces energy consumption, requiring only 43.4 kWh to produce 1 kg of H2, saving 6.1 kWh of energy power. To our excitement, we analyzed the electrolyte after stability measurement and found the production of GRA, an important platform molecule for chemical industry and medical treatment. This research provides a promising and sustainable approach for efficient hydrogen production and the value-up of biomass feed-stock.

Maxillary Sinus Augmentation with Autogenous Tooth Grafting Material: A Systematic Review.

The aim of this systematic review was to determine whether autogenous tooth grafting material (ATGM) is as safe and effective as other bone substitutes used for maxillary sinus augmentation procedures, evaluating histomorphometric and/or histological data, implant primary stability, associated complications and radiographic bone height measurements. An automated electronic search was conducted using four databases (Medline/PubMed, Scopus, Web of Science and Cochrane Library), supplemented by a manual search, to identify clinical human studies using particulate ATGM for the aforementioned procedure. The included studies had a sample size of at least four patients and were published before 31st July 2024. The Newcastle-Ottawa scale (NOS) and Joanna Briggs Institute (JBI) Critical Appraisal Checklist were used to assess the risk of bias in cohort studies and case series, respectively. Seven studies were included in the descriptive analysis, obtaining 128 participants (46.8% only treated with ATGM) and 192 placed implants. Due to the heterogeneity of the studies, meta-analysis could not be performed. The authors concluded that ATGM appears to be a feasible and safe alternative for maxillary sinus augmentation procedures. These results should be interpreted with caution due to the limited amount of scientific evidence on this topic and the heterogeneity between the included studies.

Limits of Stability during a Therapeutic Exercise Intervention for Instability: Progression, Responders' and Non-Responders' Analysis and Predictors.

Background/Objectives: Instability is one of the main symptoms in patients with vestibular and neurological disorders and therapeutic exercise interventions are increasing in popularity as a form of treatment. Additionally, the limits of stability measurement are known to be a good tool for balance evaluation and monitoring of these interventions. The aim of this work is to better understand how a specific protocol provokes changes on this variable and to study the characteristics of those who do and do not respond to it. Methods: A retrospective study was developed with the data of 40 patients treated in the Otorhinolaryngology department in Clínica Universidad de Navarra (Madrid, Spain). They had an initial reduction in limits of stability, completed the proposed protocol with home-based and hospital-based exercises and with frequent limits of stability remeasurement, and were assisted to a follow-up retest after 1-2 months. Results: A progressive improvement in limits of stability measure was developed through the intervention and was partially retained at follow-up visit. Several differences were found between those patients who improved with the treatment (responders) and those who did not improve (non-responders). More specifically an initial measure of the limits of stability was able to differentiate those groups with a cut-off data of 56 cm2. Conclusions: The proposed protocol was able to induce motor learning in patients included in this study with good retention after 1-2 months. Furthermore, there is some variability in how patients respond to the treatment. Age and diagnosis should be considered and an interesting cut-off data for clinal decision making was found.