Min Duration Research Articles

Characterization of intraocular pressure variability in conscious rats

Elevation of mean intraocular pressure (IOP) has long been recognized as a leading risk factor for glaucoma. Less is known about the possible contribution of moment-to-moment variations in IOP to disease development and progression due to limitations of tonometry, the prevailing method of IOP measurement. Tonometry provides good estimates of mean IOP but not IOP variance. The aim of this study was to quantitatively characterize IOP variability via round-the-clock IOP telemetry in conscious unrestrained rats. The anterior chamber of one eye was implanted with a microcannula connected to a wireless backpack telemetry system, and IOP data were collected every 4 s for one week. The cannula was then repositioned under the conjunctiva, and control data were collected for an additional week. IOP statistics were computed in 30-min intervals over a 24-h period and averaged across days. All animals exhibited a diurnal variation in mean IOP, while deviations about the mean were independent of time of day. Correlation analysis of the deviations revealed transient and sustained components, which were respectively extracted from IOP records using an event detection algorithm. The amplitude and interval distributions of transient and sustained events were characterized, and their energy content was estimated based on outflow tissue resistance of rat eyes. Transient IOP events occurred ∼231 times per day and were typically ≤5 mmHg in amplitude and 2–8 min in duration, while sustained IOP events occurred ∼16 times per day and were typically ≤5 mmHg in amplitude and 20–60 min in duration. Both persisted but were greatly reduced in control recordings, implying minor contamination of IOP data by motion-induced telemetry noise. Sustained events were also often synchronous across implanted animals, indicating that they were driven by autonomic startle and stress responses or other physiological processes activated by sensory signals in the animal housing environment. Not surprisingly, the total daily fluidic energy applied to resistive outflow pathways was determined primarily by basal IOP level. Nevertheless, transient and sustained fluctuations collectively contributed 6% and diurnal fluctuations contributed 9% to daily IOP energy. It is therefore important to consider the cumulative impact of biomechanical stress that IOP fluctuations apply over time to ocular tissues.

Response surface optimization and support vector regression modeling of microwave-assisted essential oil extraction from cumin seeds

The current research involved creating models using Response Surface Methodology (RSM) and Support Vector Regression (SVR) to forecast the amount of extractable essential oil that can be obtained from powdered cumin seeds. Influence of microwave power (140–280–420–560–700 W), amount of water (500–600–700–800–900 ml), duration of distillation (30–45–60–75–90 min) and soak time (15–30–45–60–75 min) on essential oil yield were investigated. Microwave Assisted Extraction (MAE) allowed higher recoveries compared to conventional Soxhlet extraction, without altering the chemical components of the extract. A five-level four FCC experimental design was developed using Minitab (15.1.20.0). A total of 31 runs were performed in microwave-assisted extraction apparatus. Experimental data obtained was then used for developing RSM and SVR models for the prediction of the yield of essential oil. The optimum conditions for maximum yield of cumin oil were given by RSM. Maximum yield of 3.4 ml (0.017 ml/g) was found at 140 W of microwave power, 500 ml of water, 90 min duration of distillation, and 15 min of soak time. In this work, epsilon SVR with RBF kernel was used. The grid search (depth-first search) methodology was applied for tuning the values of epsilon, gamma, and cost using the LIBSVM module on the MATLAB interface. The statistical parameters namely, average absolute relative error (AARE), coefficient of determination (R2), standard deviation (SD), and root mean square error (RMSE) were selected as the performance parameters. The developed SVR model was compared with the RSM model. The AARE values of 2.27% and 1.29%, R2 values of 0.86 and 0.99, SD values of 1.73 and 0.29, and RMSE values of 0.0284 and 0.0132 were obtained for RSM and SVR models respectively. It is found that SVR is more accurate and better tool for modeling of MAE process.

Standardized in vitro bleeding tests in a non-coated novel hybrid prosthesis for frozen elephant trunk demonstrates minimal oozing during full heparinization, supported by clinical data.

Recent reports have questioned the blood impermeability of the novel frozen elephant trunk (FET) device E-vita Open NEO© (EO-NEO). Therefore, standardized in vitro bleeding tests using porcine heparinized blood were performed, as well as stress testing on the blood tightness of the collar suture line, to investigate this observation. EO-NEO prostheses were examined in vitro for blood permeability in three test series. Initially, antegrade perfusion with heparinized porcine blood [activated clotting time (ACT) of 500 s, with a 60 min duration] was performed, followed by ante/retrograde testing via the EO-NEO side port. Testing of the collar suture line under a tension of 10 Newton (N) within a suspension device (blood pressure 120 mmHg, ACT of 560 s, 1 min duration) was carried out with the suture material force fiber white (FFWs) yarn, using standard fixation (5 stitches/cm), FFWh yarn in hemostatic fixation (15 stitches/cm), and flow weave yarn (FWYh). Blood permeability testing of EO-NEO through the prosthetic lumen or via the side port demonstrated minor leakage without statistical difference between the standard and hemostatic suture lines or suture materials used, or positioning on the crimped or tapered portion (p > 0.05). The specific collar anastomosis testing demonstrated leakage volumes of 140 ml/min for FFWs vs. 16 ml/min for FFWh (p = 0.02), vs. 9 ml/min with the FWYh (p = 0.01). Different blood leakage tests showed minimal oozing and no difference in blood loss through the fabric and different collar suture lines, but unphysiological pressurized retrograde perfusion of the collar region showed significantly less leakage using FWYh and FFWh, prompting production modification of EO-NEO. Clinical results confirmed low blood loss using this novel FET device.

Kinetics of Aluminum and Scandium Extraction from Desilicated Coal Fly Ash by High-Pressure HCl Leaching

Coal fly ash (CFA) is a waste that forms via coal combustion in thermal power stations. CFA consists of numerous components, whose recovery can address environmental and resource concerns associated with sustainable development. Most of the alumina (Al2O3) and rare-earth elements (REEs) in CFA are contained in the amorphous glassy mass and in the refractory mullite phase (3Al2O3·SiO2), which can be dissolved only using high-pressure acid leaching (HPAL). In this paper, the method of preactivation of CFA by treatment with a highly concentrated NaOH solution is used to increase the efficiency of Al and Sc extraction during HPAL. This method allows for the elimination of an inert aluminosilicate layer from the surface of mullite, transferring the REEs into an acid-soluble form. The Al and Sc extraction can reach 80% after HCl HPAL at T = 170 °C and a 90 min duration. According to the kinetic data, the dissolution of Al follows the surface chemical reaction and intraparticle diffusion shrinking core models in the initial and later stages of leaching, respectively. A high activation energy of 52.78 kJ mol−1 was observed at low temperatures, and a change in the mechanism occurred after 170 °C when the activation energy decreased to 26.34 kJ mol–1. The obtained activation energy value of 33.51 kJ mol−1 for Sc leaching indicates that diffusion has a strong influence at all studied temperatures. The residue was analysed by SEM-EDX, XRF, BET, and XRD methods in order to understand the mechanism of DCFA HPAL process.

HipHop2SToP a community-led health promotion initiative empowering Aboriginal youth in the Kimberley region of Western Australia: a process evaluation.

For millennia, Aboriginal people's ways of knowing, doing and being were shared through art, song, and dance. Colonisation silenced these ways, affecting loss of self-determination for Aboriginal people. Over the past decade in Australia, hip-hop projects have become culturally appropriate approaches for health promotion. When community led, and Aboriginal worldviews centralised, hip-hop workshops are more likely to be effective. In 2020, during the COVID-19 pandemic, a community-led health promotion hip-hop music video, 'HipHop2SToP' was produced involving young people in Dampier Peninsula communities address healthy skin and healthy living practices. We report here a qualitative process evaluation of the HipHop2SToP project. Participants who had been involved in the planning and production of HipHop2SToP were selected using a purposive approach and invited either by email or face-to-face to participate in semi-structured interviews and share their experiences. Semi-structured interviews ranged from 30 to 60 min in duration and were conducted either face-to-face or virtually over MS Teams. Due to personal time constraints, two participants provided written responses to the semi-structured questions. All interviews were audio-recorded with consent and saved as a digital recording in a de-identified format. All audio recordings were transcribed verbatim and uploaded into QSR NVivo v12 along with written responses. As a health promotion project, the critical success factors were community-ownership and discovering novel ways to collaborate virtually with remote communities using Microsoft (MS) software. Highlights included observing the young people actively engaged in the project and their catchy lyrics and key messaging for environmental health and skin infections. COVID-19 presented some challenges. Gaps in communication, clarification of stakeholder roles and expectations, and post-production outcomes were also identified as challenges. HipHop2SToP validates the need for Aboriginal community led health promotion programs. While creating some challenges COVID-19 also strengthened community ownership and created novel ways of maintaining relationships with remote Aboriginal communities. Future hip-hop projects would benefit from clarity of roles and responsibilities. Strengthening post-production outcomes by including a launch and well-planned, targeted communication and dissemination strategy will ensure the wider translation of important health messages and potential strengthen sustainability.

Extracting juice from dates (Phoenix dactylifera L.) using response surface methodology: Effect on pH, vitamin c, titratable acidity, free amino nitrogen (FAN) and polyphenols

The aim of this text is to investigate the effects of temperature, time, volume/mass ratio, and enzyme volume on various properties of date juice extracted from the "Bournow" cultivar, and to optimize the extraction process to maximize the levels of free amino acids, total polyphenols, vitamin C, and pH. The extraction technique was used to obtain date juice for use in the beverage industry from the "Bournow" cultivar. The effects of temperature, time, volume/mass ratio, and enzyme volume on free amino acid, total polyphenols, vitamin C, and pH levels were then investigated using a design centered on four parameters. All multivariate polynomial models of second degree with interactions were discovered and validated. To optimize responses, multiresponse optimization was utilized. The center composite design (CCD) determined the following response ranges: 4.21 to 5.62 pH; 45 to 126.66 mg/L vitamin C; 2.7 to 6.87 g GA/100 g total polyphenols; and 429.94 to 615.55 mg/L free amino acids. The selected factors had varying effects on the pH, vitamin C, total polyphenols, and free amino acid responses, with simple, quadratic, and interaction contributions leading to significant increases or decreases. Multi-response optimization, the objective of which was to maximize all responses besides pH in order to produce an abundant juice, resulted in the following compromise: 95 °C temperature; 10 min duration; 2:1 water/pulp ratio; and 0.5 ml of pectinase. The optimal values simulated yielded the following respective maxima: pH is 4.13; vitamin C is 116.5 mg/L; total polyphenols are 6.25 g GA/100 g; and free amino acids are 587.88 mg/L. This study successfully optimized the extraction technique for obtaining date juice from the "Bournow" cultivar. The results provide valuable insights for the beverage industry. Future prospects include further research on the sensory properties and shelf life of date juice, as well as exploring its potential applications in other food and beverage products.

Novel interface engineering of LDH-based materials on Mg alloy for efficient photocatalytic systems considering the geometrical linearity of condensed phosphates

This study presents a facile and rapid method for synthesizing novel Layered Double Hydroxide (LDH) nanoflakes, exploring their application as a photocatalyst, and investigating the influence of condensed phosphates’ geometric linearity on their photocatalytic properties. Herein, the MgO film, obtained by plasma electrolysis of AZ31 Mg alloys, was modified by growing an LDH film, which was further functionalized using cyclic sodium hexametaphosphate (CP) and linear sodium tripolyphosphate (LP). CP acted as an enhancer for flake spacing within the LDH structure, while LP changed flake dispersion and orientation. Consequently, CP@LDH demonstrated exceptional efficiency in heterogeneous photocatalysis, effectively degrading organic dyes like Methylene blue (MB), Congo red (CR), and Methyl orange (MO). The unique cyclic structure of CP likely enhances surface reactions and improves the catalyst's interaction with dye molecules. Furthermore, the condensed phosphate structure contributes to a higher surface area and reactivity in CP@LDH, leading to its superior photocatalytic performance compared to LP@LDH. Specifically, LP@LDH demonstrated notable degradation efficiencies of 93.02%, 92.89%, and 88.81% for MB, MO, and CR respectively, over a 40 min duration. The highest degradation efficiencies were observed in the case of the CP@LDH sample, reporting 99.99% for MB, 98.88% for CR, and 99.70% for MO. This underscores the potential of CP@LDH as a highly effective photocatalyst for organic dye degradation, offering promising prospects for environmental remediation and water detoxification applications.

Design and Control of an Assistive Device for Elbow Effort-Compensation

In this article, we introduce an assistive device for the elbow joint that is easily wearable, lightweight, and cable driven using a series elastic actuation principle implemented by an endless-shape elastic bungee element. This type of elastic element is selected due to its intrinsic damping, and compliant features similar to human muscles, which provide mechanical filtering against dynamic uncertainties such as impulsive forces, and oscillated movements because of possible controller issues. Furthermore, a spool system is designed targeting to maximize the transmission of the generated elastic force to the wearer while avoiding multiple coiling for the cable wrap/release operation. The design parameters of the device are selected through design and optimization studies. The manufactured actuator's performance is validated on a rigid link under position and force control modes. To demonstrate the effectiveness of the elastic element, we conducted actuator validation tests with and without bungee cases. The results show that while the bungee-integrated setup can transfer the generated elastic force to the link without oscillation at different frequency movements (0.05–0.16 Hz), the bungee-excluded setup performs unstable movements under the same control gains, producing 50.74% more vibrations detected through fast Fourier transform analysis. In addition, to test the system under aggressive conditions, we applied impacts to it, and the results indicate that the damping ratio index of the bungee incorporated system is 56.14% more than that of without bungee case, demonstrating the intrinsic safe behavior of the mechanism. Finally, the device is assessed on six human subjects (different arm weights and dimensions) in a simulated industrial painting task with 5 min duration, with an average <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$22.3^\circ /\text{s}$</tex-math></inline-formula> elbow velocity under force control. The average effort reduction on biceps muscle among the subjects is measured 64.42% with respect to the without assistance test.

Finite integral transform with homogenized boundary conditions solution of transient heat conduction applied to thermal plug and abandonment of oil wells

After the end of productive life of a geological oil reservoir, a set of operations for well Plug and Abandonment (P&A) is performed to recover the soil layers to its natural state. As traditional P&A techniques are expensive activities, alternative technologies are gaining renewed interest for capital expenditure reduction and leak risks mitigation. Hence, the Thermal Plug and Abandonment (TP&A) procedure is here investigated by focusing on the fulfillment of two intermediate milestones, combining new technology with conventional P&A practices. The first milestone consists in applying a thermite exothermic reaction to generate enough heat for melting the entire thickness of the production tube. The second milestone aims to determine if the resulting molten section has sufficient dimensions to allow for the passage of the cement pumped downhole, thus ensuring the complete sealing of the oil well's cross-section. The thermal investigation was conducted by applying a homogenized form of the Finite Integral Transform (FIT) analytical framework to solve the transient heat conduction equation in 2-D polar coordinates. The well assembly was geometrically discretized as a multilayered circular domain. The thermite reaction was modeled as a theoretical volumetric heat source profile dependent on both time and space, placed in the innermost layer. While a pure FIT approach may only be used to solve Neumann boundary conditions, the combined scheme applied here copes with any type of boundary condition. Hence, the integration of FIT with homogenization satisfies the Dirichlet condition requirement of the TP&A procedure. The methodology was verified through an equivalent Finite Volume Method (FVM) solution obtained using a commercial code. The results evidenced that within the 5 min duration of thermite reaction, the entire circumferential section of the production tube exceeds the steel melting temperature by at least 227 °C, thus fulfilling both milestones set. The research outcomes are part of a series of investigation steps to thoroughly analyze the new TP&A technology with regard to its compliance with the regulatory norms established to P&A operations.

Formulation Of Self Micro-emulsifying Drug Delivery System For Ketoconazole

The present investigation was undertaken with an objective to prepare the SMEDDS of ketoconazole in order to improve the bioavailability of lipophilic drugs. A ternary phase diagram was constructed in the absence of ketoconazole. The results revealed that span 60 and PEG 600 used in ratios of 2:1 (F17-18) and 3:1 (F23-24) exhibited largest micro-emulsion area and shortest emulsification time (less than 1 min). It was observed that with increase in the ratio of the PEG 600, spontaneity of the self-emulsification process got increased. A fixed ketoconazole concentration of 5% w/w was selected to be loaded in all self-emulsifying formulations. The prepared formulations were kept in closed containers and tested for thermodynamic stability. All the formulations passed the thermodynamic stability studies without any signs of phase separation and precipitation during alternative temperature cycles (4°C and 40°C), freeze thaw cycles (-21°C and +25°C) and centrifugation at 10,000 g indicating good stability of formulations and their emulsions. The in vitro dissolution studies revealed the drug release profiles for the SMEDDS. All the formulations exhibited quick drug release characteristics and almost complete drug release in 15-20 minutes. In contrast, the pure drug exhibited only a maximum of 39.63% release in 60 min duration.

Ultrasonic intensification of flocculation filtration for kaolinite: Unraveling mechanisms and performance gains

The mining industry produces substantial tailings, which present environmental challenges. This necessitates the adoption of efficient solid–liquid separation technologies to convert these tailings into a dewatered and environmentally manageable dry stack form. This work aims to investigate the transformative potential of ultrasonic treatment in the context of flocculation filtration for kaolinite dewatering and to elucidate the underlying mechanism. Through Uniform Design optimization, we determined the optimal conditions: 40 W ultrasound power, 12 min duration, and 40 kHz frequency. Experimental validation emphasized the effectiveness of these parameters, revealing a 2.02 % reduction in filter cake water content alongside a significant 2.5-fold enhancement in filtration rate. Furthermore, this combined treatment surpassed the performance of flocculation alone, resulting in the formation of smaller, more desirable flocs. The 3D structural analysis of the filter cake using micro-CT revealed that the synergistic application of ultrasound and flocculation led to a notable decrease in overall porosity. More significantly, there was a substantial reduction of isolated pores (down to 9.32 %). This phenomenon remarkably improved pore connectivity, enlarged pore and channel radii, and effectively mitigated capillary resistance during water transport. Additionally, the filter cake subjected to ultrasound and flocculation treatment showcased a uniform distribution of pore space, indicative of a promising trend towards homogenization across different sections. Ultrasound plays a role in refining flocs and suppressing segregation during tailings flocculation and filtration processes, primarily attributed to the cavitation and acoustic streaming effects of ultrasound. This comprehensive investigation sheds light on the transformative role of ultrasonic treatment in advancing the efficiency and performance of kaolinite dewatering processes.

Large scale study on influence of biopolymer to mitigate wind induced sand erosion with durability analysis

The desertification is a serious threat that affects the sustainable agriculture, ecosystem, and economic progress of society. There is an urgent need for an environment friendly, cost-effective, durable, and practical approach to mitigate wind induced erosion. The present study introduces a novel approach through large scale testing using biopolymer, including durability analysis. The research investigates the influence of biopolymer namely Acacia gum (AG) to mitigate wind induced sand erosion. For the experimental setup, rectangular trays (180 cm × 60 cm × 15 cm) containing 11 erosion pins (three rows along the length, in a staggered way at equal spacing) have been filled with desert sand. Solutions have been prepared using biopolymer concentrations (1%, 2%, and 3%) mixed with water. The prepared solution was sprayed onto specimens and the treated samples were then left for air drying (7 and 28 days curing period). The study has been performed on summer days with an average temperature of 40 °C. After biotreatment, the specimens were examined in a wind tunnel at variable wind speeds of 6, 10, and 15 m/s to measure sand loss rate (SLR) for different wind intervals (i.e., 1, 2, 3, 4, and 5 min). Surface strengths were assessed using a pocket penetrometer. To check the durability of biotreated sand samples, 28 days curing period samples, with all biopolymer percentages have gone through 5 wetting and drying cycles (WDC). After the last WDC, samples were left again for 28 days and then experienced all tests. The minimum and maximum SLR for desert sand ranged from 17 kg/m² at 6 m/s and 1 min duration to 123 kg/m² at 15 m/s and 5 min duration respectively. Instead biotreated sand samples presented negligible SLR. Surface strength increased with increasing biopolymer concentration and a curing period. The maximum surface strength was 334.47 kPa recorded at 3% concentration during the curing period of 28 days. Further analysis involving SEM, EDX, and PXRD, confirmed sand particle bonding. For surface strength, 3% biopolymer concentration consistently produced positive outcomes, even after undergoing 5 WDC.

Outback Quit Pack: Feasibility trial of outreach smoking cessation for people in rural, regional, and remote Australia.

Tobacco smoking rates are higher in rural, regional, and remote (RRR) areas in Australia, and strategies to improve access to quit supports are required. This pilot study examined the feasibility of a smoking cessation intervention for people in RRR areas who smoke with the intention of using this data to design a powered effectiveness trial. A randomised controlled trial (RCT) of the feasibility of a 12-week 'Outback Quit Pack' intervention consisting of mailout combination nicotine replacement therapy (NRT) and a proactive referral to Quitline, compared with a minimal support control (1-page smoking cessation support information mailout) was conducted between January and October 2021. Participants recruited via mailed invitation or Facebook advertising, were adults who smoked tobacco (≥10 cigarettes/day) and resided in RRR areas of New South Wales, Australia. Participants completed baseline and 12-week follow-up telephone surveys. Outcomes were feasibility of trial procedures (recruitment method; retention; biochemical verification) and acceptability of intervention (engagement with Quitline; uptake and use of NRT). Facebook advertising accounted for 97% of participant expressions of interest in the study (N = 100). Retention was similarly high among intervention (39/51) and control (36/49) participants. The intervention was highly acceptable: 80% of the intervention group had ≥1 completed call with Quitline, whilst Quitline made 3.7 outbound calls/participant (mean 14:05 mins duration). Most of the intervention group requested NRT refills (78%). No differences between groups in self-reported cessation outcomes. Biochemical verification using expired air breath testing was not feasible in this study. The Outback Quit Pack intervention was feasible and acceptable. Alternative methods for remote biochemical verification need further study. SO WHAT?: A powered RCT to test the effectiveness of the intervention to improve access to evidence-based smoking cessation support to people residing in RRR areas is warranted.

From seed to sprout: Unveiling the potential of non-thermal plasma for optimizing cucumber growth

Background and aimsNumerous strategies for enhancing seed germination and growth have been employed over the decades. Despite these advancements, there continues to be a demand for more effective techniques, driven by the growing global population. Recently, various forms of non-thermal atmospheric pressure plasma have garnered attention as environmentally friendly, safe, and cost-effective methods to enhance the agricultural and food sectors. This study explores the remarkable impact of non-thermal plasma (NTP) treatment on cucumber (Cucumis sativus L.) seed germination. MethodsA cost-effective, custom-designed power supply operating at line frequency was used for treating seeds, with exposure times ranging from 1 to 7 min. Various germination parameters, including water contact angle measurements, mass loss, water imbibition rate, and seedling length, were evaluated to assess the impact of plasma treatment on seed germination. ResultsCucumber seeds exposed to NTP treatment for 3 min and 5 min durations showed significant germination improvements, notably a 57.9 ± 4.25 % higher final germination percentage, 14.5 ± 3.75 % reduced mean germination time, and a remarkable 90.6 ± 4.64 % increase in germination index compared to the control. These results suggest that NTP treatment enhanced seed coat permeability, triggered essential biochemical processes, and expedited water absorption and nutrient assimilation, ultimately fostering faster and more synchronized germination. ConclusionsOur findings underscore the potential of NTP as an innovative approach to improving seed germination in agricultural practices.

Synergistic effect on silicon surface under low energy he ion irradiation at elevated temperatures

One of the major challenges in nuclear fusion, nanolithography, and various industries is the effect of low energy ion irradiation on the surface morphology of materials. For example, the effect of low energy irradiation on plasma-facing materials' lifetime in fusion reactors, the effect on the optical systems in nanolithography laser produced plasma devices, and the effect on mass production of effective and flexible anti-reflecting coatings in photovoltaic (PV) industry. Silicon and carbides in particular, showed interest in nuclear fusion as potential wall materials, as in mirror designs for nanolithography devices, and as coatings in PV system components. Recently innovative novel Si nanostructures such as nanocones (NCs) demonstrated great feasibility in several areas including the next generation PV cells, batteries, supercapacitors, nano-optoelectronics, photonics, and energy storage devices. Their unique electronic properties and significantly higher absorption over a wide broadband range, offer paramount potential in various fields including microelectronics, optoelectronics, photonics, photovoltaics, biology, sensors, templet for selective growth (on nanostructured substrates), fast electronic devices, and even in high- density data storage. We tailor Si NCs using simultaneous low energy helium (He) ion irradiation on planar Si (111) and (100) and Ta metal masks. In a series of successive experiments, three key parameters, temperature, flux, and presence of Ta metal impurity, were tuned to study the progression of nanostructure development, as well as the effect of these nanostructures on key material properties. Before performing He ion sputtering experiments, 100 eV Ar+ ion irradiations, for 10 min duration, were also performed in-situ in each case for removing any preexisting SiO2 form planer Si substrates. Clear and distinctive progressions of NC development were found during the tuning of each parameter. During the temperature dependent studies, we clearly observed a sequential progression from thicker and less dense cones (773 K) to finer and more densely packed NCs (1073 K). On the other hand, during the case of flux dependent studies, it was found that increasing flux increases the size of the NCs, with low flux resulting in sparsely placed nanodots, and high fluxes resulting in large conglomerates. Finally, the effect of Ta impurity shows an increased propensity for NCs development. In addition, using optical-reflectivity studies we clearly observed a significant reduction (from ∼65 to almost zero) in optical reflectivity.

Effects of physical exercise interventions on cognitive function in Parkinson's disease: An updated systematic review and meta-analysis of randomized controlled trials

ObjectiveTo determine whether physical exercise interventions can improve cognitive function, including overall performance and specific domains, in patients with Parkinson's disease (PD) and to provide potential evidence on how cognitive benefits can be optimized by exercise prescriptions. MethodsUsing PubMed, Web of Science, and Cochrane Library (from inception to August 2022), four independent reviewers screened the search results and extracted data from randomized controlled trials of physical exercise interventions in patients with PD with an outcome measure of cognitive function. Random-effects meta-analysis models were used to report standardized mean differences (SMDs) with 95 % confidence intervals (CIs). ResultsTwenty-one randomized controlled trials including 761 patients with PD were eligible for inclusion. Physical exercise interventions led to significant improvements in global cognitive function (SMD = 0.69; 95 % CI = 0.31 to 1.06; P < 0.001). With respect to cognitive domains, the significant effect of exercise was found on executive function (SMD = 0.94; 95 % CI = 0.05 to 1.83; P = 0.039), but not on attention/working memory, language, memory, and visuospatial function. In moderator variable analyses, the effect on global cognition was observed in combined exercise programs (SMD = 0.79; 95 % CI = 0.46 to 1.12; P < 0.001), whereas there were no significant positive effects in aerobic exercise programs, strength exercise programs, and flexibility exercise programs. In addition, exercise interventions of light-to-moderate intensity with at least 60 min in duration, and of any frequency or period, were beneficial to the global cognitive function. ConclusionThis updated systematic review and meta-analysis suggests that physical exercise interventions are effective in improving global cognitive function and, to a lesser extent, executive function in patients with PD. At least 60 min a day of combined exercise programs on as many days of the week as feasible may be recommended as the non-pharmacological therapeutic option to improve cognitive function.

Transcutaneous auricular vagus nerve stimulation attenuates inflammatory bowel disease in children: a proof-of-concept clinical trial

BackgroundVagus nerve stimulation is an investigational anti-inflammatory therapy targeting the nervous system to modulate immune activity. This study evaluated the efficacy and safety of transcutaneous auricular VNS (ta-VNS) in patients with pediatric-onset Crohn’s disease (CD) or ulcerative colitis (UC).MethodsParticipants were 10–21 years of age with mild/moderate CD or UC and fecal calprotectin (FC) > 200 ug/g within 4 weeks of study entry. Subjects were randomized to receive either ta-VNS targeting the cymba conchae of the external left ear, or sham stimulation, of 5 min duration once daily for a 2-week period, followed by a cross over to the alternative stimulation for an additional 2 weeks. At week 4, all subjects received ta-VNS of 5 min duration twice daily until week 16. Primary study endpoints were clinical remission, and a ≥ 50% reduction in FC level from baseline to week 16. Heart rate variability measurements and patient-reported outcome questionnaires were completed during interval and week 16 assessments.ResultsTwenty-two subjects were enrolled and analyzed (10 CD, 12 UC). Six of 10 with CD had a wPCDAI > 12.5 and 6/12 with UC had a PUCAI > 10 at baseline, correlating to mild to moderate symptom activity. Among the 12 subjects with active symptomatic disease indices at baseline, clinical remission was achieved in 3/6 (50%) with CD and 2/6 (33%) with UC at week 16. Despite all subjects having FC levels ≥ 200 within 4 weeks of enrollment, five subjects (4 UC, 1 CD) had FC levels < 200 at the baseline visit and were excluded from the FC analysis. Of the remaining 17, median baseline FC was 907 µg/g (IQR 411–2,120). At week 16, 11/17 (64.7%) of those with baseline FC ≥ 200 had a ≥ 50% reduction in FC (95% CI 38.3—85.8). In the UC subjects, there was an 81% median reduction in FC vs baseline (833 µg/g; p = 0.03) while in the CD subjects, median reduction in FC at 16 weeks was 51% (357 µg/g; p = 0.09). There were no safety concerns.ConclusionNoninvasive ta-VNS attenuated signs and symptoms in a pediatric cohort with mild to moderate inflammatory bowel disease.Trial RegistrationNCT03863704—Date of registration 3/4/2019.

Duration and extent of solar X-ray flares and shortwave fadeouts likely to impact high frequency radio wave propagation based on an evaluation of absorption at 30 MHz

High frequency (HF; 3–30 MHz) radio wave propagation can be impacted by absorption that results from enhanced photoionization in the dayside D-region following a solar X-ray flare. A database of >25,000 solar X-ray flares was evaluated to characterize the relationship between flare duration and the peak of the 0.1–0.8 nm solar X-ray flux. Expressions describing the mean and 90th percentile duration were developed. Based on these models, mean durations of 13, 18, 27, and 39 min and 90th percentile durations of 30, 48, 77, and 123 min are expected for C1, M1, X1 and X10 solar X-ray flares, respectively. A probability distribution of flare durations was developed to describe the probability of flare duration lasting 0–15, 15–30, 30–45, 45–60, 60–90, >90 min. In addition to flare duration, the duration of the expected impact to HF radio waves was evaluated. By considering examples where HF radio wave propagation in the 5–15 MHz range was impacted by space weather, a 0.5 dB threshold at 30 MHz was observed in samples of riometer data. Absorption modelled at 1-min increments from 1986 to 2017 was evaluated to create a probability distribution of impact duration, defined as the length of time the modelled 30 MHz absorption exceeded 0.5 dB during a single event. Modelled absorption was further evaluated to demonstrate the geographic extent of enhanced absorption, and to determine the minimum solar X-ray flux required to exceed the 0.5 dB impact threshold at a given latitude as a function of solar zenith angle and time of year. The results of this paper provide a better understanding of the impact of solar X-ray flares on high frequency radio wave propagation and aid in the development of tools and services for mitigating space weather impacts to systems that rely on HF radio wave propagation.

Time scales of adaptation to context in horizontal sound localization.

Psychophysical experiments explored how the repeated presentation of a context, consisting of an adaptor and a target, induces plasticity in the localization of an identical target presented alone on interleaved trials. The plasticity, and its time course, was examined both in a classroom and in an anechoic chamber. Adaptors and targets were 2 ms noise clicks and listeners were tasked with localizing the targets while ignoring the adaptors (when present). The context was either simple, consisting of a single-click adaptor and a target, or complex, containing either a single-click or an eight-click adaptor that varied from trial to trial. The adaptor was presented either from a frontal or a lateral location, fixed within a run. The presence of context caused responses to the isolated targets to be displaced up to 14° away from the adaptor location. This effect was stronger and slower if the context was complex, growing over the 5 min duration of the runs. Additionally, the simple context buildup had a slower onset in the classroom. Overall, the results illustrate that sound localization is subject to slow adaptive processes that depend on the spatial and temporal structure of the context and on the level of reverberation in the environment.

Beyond small-scale transients: A closer look at the diffuse quiet solar corona

Aims. Within the quiet Sun corona imaged at 1 MK, much of the field of view consists of diffuse emission that appears to lack the spatial structuring that is so evident in coronal loops or bright points. Our aim is to determine if these diffuse regions are categorically different in terms of their intensity fluctuations and spatial configuration from the better-studied dynamic coronal features. Methods. We analyzed a time series of observations from Solar Orbiter’s High Resolution Imager in the extreme ultraviolet to quantify the characterization of the diffuse corona at high spatial and temporal resolutions. We then compared this to the dynamic features within the field of view, mainly a coronal bright point. Results. We find that the diffuse corona lacks visible structuring, such as small embedded loops, and that this is persistent over the 25 min duration of the observation. The intensity fluctuations of the diffuse corona, which are within ±5%, are significantly smaller in comparison to the coronal bright point; however, the total intensity observed in the diffuse corona is on the same order as the bright point. Conclusions. It seems inconsistent with our data that the diffuse corona is a composition of small loops or jets or that it is driven by discrete small heating events that follow a power-law-like distribution. We speculate that small-scale processes such as magnetohydrodynamic turbulence might be energizing the diffuse regions, but at this point we cannot offer a conclusive explanation for the nature of this feature.