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Journal of Molecular Modeling Jul 2024In order to synthesize InN nanoparticles (NPs), we have simulated the co-implantation of indium (In) and nitrogen (N) ions on silicon (Si) and silicon oxide (SiO)...
CONTEXT
In order to synthesize InN nanoparticles (NPs), we have simulated the co-implantation of indium (In) and nitrogen (N) ions on silicon (Si) and silicon oxide (SiO) substrates with flat-top profiles. The choice of flat-top profile is to increase the possibility of creating homogeneous zone with well-distributed InN nanoparticles over the entire implanted layer. In this view and to obtain these flat-top profiles, we must do several implantations with different doses and energies optimized by our program. The simulation results performed on a silicon substrate < 111 > , give an average dose of 4.30 × 10 at./cm and the implantation energies were In (10, 46, and 180 keV) and N (13 and 35 keV). But for the SiO substrate, the total mean dose is about 5.20 × 10at./cm for each Indium and nitrogen ion. The respective implantation energies were In (23, 63, and 120 keV) and N (12 and 28 keV) in an average depth of approximately 100 nm. The implantations were performed in a 206-nm-thick (SiO) layer thermally grown on < 100 > silicon. Subsequent thermal treatments (500-900 °C) lead to the formation of nanoparticles precipitates of the compound semiconductor (InN) and to cure the oxide defects during different periods of time. To verify that indium (In) and nitrogen (N) ions were located according to flat curves, we used RBS technical and study the formation (InN) stoichiometric compound several techniques, were used such as X-ray diffraction, UV-visible-IR, and photoluminescence (PL) spectroscopy.
METHODS
The simulated profiles have been chosen with the aim that the implanted element not exceeding 5-10 at %maximum concentration for each species. We have elaborated our program to simulate these profiles using data as input values from SRIM2008 code taking into account the sputtering factor. The optimal conditions are determined, which are the expected depth impact energies (R), the standard deviation (ΔR) and the sputtering corrosion factor (F). Through these results, a simulation program has been created which allows building flat "distribution" curves for ion implantation for each element (In and N), so that each curve is obtained from three Gaussian functions whose values are carefully chosen in relation to the optimal experimental conditions.
PubMed: 38951282
DOI: 10.1007/s00894-024-06036-6 -
The Journal of Thoracic and... Jun 2024To characterize changes in ventricular morphology in patients with hypertrophic cardiomyopathy(HCM) who develop left ventricular outflow tract(LVOT) obstruction.
OBJECTIVE
To characterize changes in ventricular morphology in patients with hypertrophic cardiomyopathy(HCM) who develop left ventricular outflow tract(LVOT) obstruction.
METHODS
We reviewed HCM patients with LVOT obstruction who underwent septal myectomy from May 2012 to June 2023. Among 68 patients initially without obstruction, documented up to 7.6 years (IQR,6.3-9.4) before the operation, a comparison was made with 78 nonobstructive HCM patients over a similar period. Patients who did not develop obstruction were matched with those who did on sex, age, and maximum septal wall thickness during the initial echocardiography, identifying 41 matched pairs. Echocardiographic data, including 5 measures of angulation, were compared between the groups.
RESULTS
The median interval between echocardiographic assessments was 7.5 years (IQR,6.3-8.1) among obstructive versus 7.3 years (IQR,6.2-9.0) in nonobstructive patients. Obstructive patients were more likely to have hypertension at both times. The maximum septal wall thickness increased within both groups (both p<0.001), but the magnitude of increase was not different between groups (p=0.130). Obstructive patients exhibited a greater increase in left ventricular (LV) mass (p<0.001) compared to nonobstructive patients (p=0.004). Aortic angulation significantly increased in 4 of the 5 measurements(all p<0.001) in obstructive patients, while nonobstructive patients showed no change. Anterior and posterior mitral valve(MV) leaflet lengths and coaptation lengths remained similar in both groups over time.
CONCLUSIONS
The development of LVOT obstruction in patients with HCM was associated with progressive LVOT angulation and increased LV hypertrophy, as reflected by LV mass. Progression to obstruction was not related to changes in the MV leaflet morphology.
PubMed: 38950769
DOI: 10.1016/j.jtcvs.2024.06.022 -
Ophthalmology. Retina Jun 2024To describe the retinal and vitreous changes in eyes showing myopic macular schisis (MMS) improvement when vitrectomy was not performed and identify triggering factors.
PURPOSE
To describe the retinal and vitreous changes in eyes showing myopic macular schisis (MMS) improvement when vitrectomy was not performed and identify triggering factors.
DESIGN
Retrospective observational study.
SUBJECTS
Patients with non-operated myopic macular schisis METHODS: The records of patients with MMS who were followed without performing surgery for more than 6 months were retrospectively reviewed, and the eyes showing an anatomical improvement were included. MMS evolution was analyzed quantitatively (central foveal thickness [CFT], parafoveal thickness, maximum height) and qualitatively (presence/absence of foveal detachment, lamellar hole, epiretinal membrane, choroidal neovascularization, inner and outer retinoschisis, vitreous status) at baseline and at the final visit. An anatomical improvement was defined as a decrease in CFT by at least 50 μm.
MAIN OUTCOME MEASURE
The rate anatomical improvement of MMS without performing vitrectomy and the morphological changes observed in these cases.
RESULTS
In a cohort of 74 non-operated eyes with MMS, MMS improved in 14 eyes (19%) after a mean follow-up of 55 ± 38 months (range: 8-138). In these improved cases, the mean decrease in CFT was 153 ± 166 μm (range: 24-635, p=0.005) and a complete resolution of MMS was observed in 9 eyes (64%). In 9 eyes (64%), the improvement was associated with visible vitreous changes in the macular area on the OCT scans. The mean visual acuity, which was already good at baseline (20/50, 0.4 ± 0.2 LogMAR), increased at the last visit (20/40, 0.3 ± 0.3 LogMAR) but without reaching significance.
CONCLUSION
This long-term follow-up analysis showed that almost 20% of MMS in eyes without indication for surgery could improve over time. In most cases, the improvement was associated with an apparent resolution of vitreous tensions.
PubMed: 38950656
DOI: 10.1016/j.oret.2024.06.017 -
Optics Letters Jul 2024A silica volume Bragg grating (VBG) is used to filter the light of a mid-infrared (mid-IR) supercontinuum laser. The VBG with a 7 µm period was inscribed with 800 nm...
A silica volume Bragg grating (VBG) is used to filter the light of a mid-infrared (mid-IR) supercontinuum laser. The VBG with a 7 µm period was inscribed with 800 nm pulses with a 100 fs duration and the phase-mask technique over a glass thickness of 3 mm. Despite silica's absorption, the VBG allows obtaining a narrowband light source tunable from 2.9 to 4.2 µm with a full width at half maximum (FWHM) of 29 nm. This demonstrates the great potential of using femtosecond-written VBGs as highly tunable, yet selective, spectral filters in the mid-IR.
PubMed: 38950257
DOI: 10.1364/OL.521708 -
Frontiers in Physiology 2024The purpose of this study was to compare acute responses between manual and automated blood flow restriction (BFR) systems.
UNLABELLED
The purpose of this study was to compare acute responses between manual and automated blood flow restriction (BFR) systems.
METHODS
A total of 33 individuals completed this study. On visit 1, arterial occlusion pressure (AOP, mm Hg), cardiovascular responses, and discomfort (RPE-D) were measured with each BFR system at rest. On visit 2, unilateral bicep curls were completed [30% one-repetition maximum; 50% AOP] with one system per arm. Muscle thickness (MT, cm) and maximal force (N) were assessed before (pre), immediately (post-0), 5 min (post-5), and 10 min (post-10) post-exercise. Ratings of perceived exertion (RPE-E) and ratings of perceived discomfort (RPE-D) were assessed throughout the exercise. AOP and repetitions were compared with Bayesian paired t-tests. Other outcomes were compared with Bayesian RMANOVAs. BF represents the likelihood of the best model vs. the null. The results are presented as mean ± SD.
RESULTS
Supine cardiovascular responses and RPE-D were similar for manual and automated (all BF ≤ 0.2). Supine AOP for manual (157 ± 20) was higher than that of automated (142 ± 17; BF = 44496.0), but similar while standing (manual: 141 ± 17; automated: 141 ± 22; BF = 0.2). MT (time, BF = 6.047e + 40) increased from Pre (3.9 ± 0.7) to Post-0 (4.4 ± 0.8; BF = 2.969e + 28), with Post-0 higher than Post-5 (4.3 ± 0.8) and Post-10 (4.3 ± 0.8; both BF ≥ 275.2). Force (time, BF = 1.246e + 29) decreased from Pre (234.5 ± 79.2) to Post-0 (149.8 ± 52.3; BF = 2.720e + 22) and increased from Post-0 to Post-5 (193.3 ± 72.7; BF = 1.744e + 13), with Post-5 to Post-10 (194.0 ± 70.6; BF = 0.2) being similar. RPE-E increased over sets. RPE-D was lower for manual than automated. Repetitions per set were higher for manual (Set 1: 37 ± 18; Set 4: 9 ± 5) than automated (Set 1: 30 ± 7; Set 4: 7 ± 3; all BF ≥ 9.7).
CONCLUSION
Under the same relative pressure, responses are mostly similar between BFR systems, although a manual system led to lower exercise discomfort and more repetitions.
PubMed: 38948082
DOI: 10.3389/fphys.2024.1409702 -
Journal of Indian Prosthodontic Society Jul 2024The aim is to determine thermal conduction by heat-activated polymethylmethacrylate (PMMA) infiltrated with 1 weight% Titanium Dioxide (TiO2) and 1 weight% Zirconium...
Effect of titanium dioxide and zirconium dioxide nanoparticle incorporation on the thermal conductivity of heat-activated polymethylmethacrylate denture base resins: An in vitro experimental study.
AIM
The aim is to determine thermal conduction by heat-activated polymethylmethacrylate (PMMA) infiltrated with 1 weight% Titanium Dioxide (TiO2) and 1 weight% Zirconium Dioxide (ZrO2) nanoparticles and to compare with that of conventional PMMA.
STUDY SETTING AND DESIGN
In vitro experimental study.
MATERIALS AND METHODS
Eighteen disc shaped specimens with a thickness of 5 mm and diameter of 50 mm, were fabricated and grouped according to the material used: Group B1 (resin infiltrated with 1 weight% TiO2), Group B2 (resin infiltrated with 1 weight% ZrO2), and Control Group B3 (heat-activated conventional PMMA resin). Disc-shaped specimens were analyzed for thermal conductivity using "modified guarded hot plate apparatus" in the thermal lab of the Indian Space Research Organisation.
STATISTICAL ANALYSIS USED
One-way ANOVA followed by Tukey's post hoc test was used to compare the arithmetic means of all three groups.
RESULTS
A statistically significant difference was noted among all three groups. Group B2 had the maximum thermal conductivity, followed by Group B1. Thermal conductivity was the least for Group B3. A post hoc comparison revealed that the difference was significant between Group B2 and Group B3.
CONCLUSION
Nano ZrO2 addition in PMMA increased its thermal conductivity. There is evidence that it improves its mechanical properties as well. Hence, Nano ZrO2 addition in PMMA is highly recommended. Nano TiO2 addition in PMMA did not provide any significant advantage in terms of thermal conductivity, but its addition in PMMA is justified because of its mechanical and antimicrobial properties.
Topics: Titanium; Zirconium; Polymethyl Methacrylate; Thermal Conductivity; Nanoparticles; Hot Temperature; Denture Bases; Materials Testing; In Vitro Techniques
PubMed: 38946506
DOI: 10.4103/jips.jips_575_23 -
Journal of Nutritional Science and... 2024Alaska pollack protein (APP), has been reported as a protein source that can enhance muscle hypertrophy more than other protein sources in animal studies. This study... (Randomized Controlled Trial)
Randomized Controlled Trial
Alaska pollack protein (APP), has been reported as a protein source that can enhance muscle hypertrophy more than other protein sources in animal studies. This study aimed to examine the effects of APP ingestion on muscle quantity and quality in young adults. Fifty-five young college students were assigned to two groups: APP and placebo (whey protein: WP) groups, and instructed to ingest 4.5 g of each protein in addition to daily meals, and to maintain their usual daily physical activities for 3 mo. Twenty-one and 23 students completed the intervention and were analyzed in APP and WP groups, respectively. The maximum knee extension torque significantly increased in both groups during the intervention. The motor unit discharge rate, which is an indicator of activation, for a given force level significantly decreased in both groups during the intervention, but its decrease in the APP group was significantly greater than in the WP group. Echo intensity of the vastus lateralis evaluated by ultrasound images significantly decreased in both groups. The muscle thickness and skeletal muscle mass did not change. Small amount of additional APP intake induces greater effects on neural activation than WP, suggesting the greater neural economy of generation of force.
Topics: Humans; Young Adult; Male; Female; Muscle, Skeletal; Dietary Proteins; Adult; Adaptation, Physiological; Gadiformes; Torque; Quadriceps Muscle; Muscle Strength; Double-Blind Method
PubMed: 38945888
DOI: 10.3177/jnsv.70.228 -
Mymensingh Medical Journal : MMJ Jul 2024Burns are very common and important injuries associated with epilepsy. Epileptics are afflicted with burns when they come in contact with fire or other burning agents... (Observational Study)
Observational Study
Burns are very common and important injuries associated with epilepsy. Epileptics are afflicted with burns when they come in contact with fire or other burning agents while seizing, due to loss of consciousness. The aim of the study was to identify the causes of burn, pattern and characteristics of burn in patients with epilepsy, duration of hospital stay and pattern of treatment in these patients. This prospective observational study was conducted in the Department of Burn and Plastic Surgery, Mymensingh Medical College Hospital, Bangladesh from January 2022 to December 2023. Epileptics were found in 0.84% (n=19) of the total admission (2274) in Burn unit. Majority of the patients were females (84.2%) and the mean age was (31.42±1.32) years. Maximum patients were housewives (78.9%). Among 19 cases, 11 cases (57.89%) had history of irregularly taking antiepileptic drugs and 8 cases (42.11%) had no history of treatment for epilepsy. Two cases (10.53%) had history of previous burn injury. Flame burn was the major etiology (89.5%). Mean total burn surface area (TBSA) was (6.94±4.12%). Most patients had full thickness burns (63.2%). Regarding distribution of burn, maximum involvement was in upper limb i.e. 68.21% cases. Surgical treatment was needed in the majority of the patients (68.5%). Mean hospital stay of these patients was (5.36±2.26) weeks. Epilepsy patients whose seizures are inadequately controlled are at increased risks of injury, especially burn. For prevention of burn, epilepsy should be treated properly.
Topics: Humans; Female; Bangladesh; Male; Adult; Burns; Epilepsy; Prospective Studies; Length of Stay; Tertiary Care Centers; Young Adult; Middle Aged; Adolescent
PubMed: 38944708
DOI: No ID Found -
Design and optimization of THz coupling in zirconia MAS rotors for dynamic nuclear polarization NMR.Journal of Magnetic Resonance (San... Jun 2024We present 3D electromagnetic simulations of the coupling of a 250 GHz beam to the sample in a 380 MHz DNP NMR spectrometer. To obtain accurate results for magic angle...
We present 3D electromagnetic simulations of the coupling of a 250 GHz beam to the sample in a 380 MHz DNP NMR spectrometer. To obtain accurate results for magic angle spinning (MAS) geometries, we first measured the complex dielectric constants of zirconia, sapphire, and the sample matrix material (DNP juice) from room temperature down to cryogenic temperatures and from 220 to 325 GHz with a VNA and up to 1 THz with a THz TDS system. Simulations of the coupling to the sample were carried out with the ANSYS HFSS code as a function of the rotor wall material (zirconia or sapphire), the rotor wall thickness, and the THz beam focusing (lens or no lens). For a zirconia rotor, the B field in the sample was found to be strongly dependent on the rotor wall thickness, which is attributed to the high refractive index of zirconia. The optimum thickness of the wall is likely due to a transmission maximum but is offset from the thickness predicted by a simple calculation for a flat slab of the wall material. The B value was found to be larger for a sapphire rotor than for a zirconia rotor for all cases studied. The results found in this work provide new insights into the coupling of THz radiation to the sample and should lead to improved designs of future DNP NMR instrumentation.
PubMed: 38943993
DOI: 10.1016/j.jmr.2024.107722 -
Food Chemistry Jun 2024This study aimed to investigate the fundamental properties, solubility, mechanical properties, barrier performance, and microstructural features of films composed of...
This study aimed to investigate the fundamental properties, solubility, mechanical properties, barrier performance, and microstructural features of films composed of corn starch and glycerol. Changes in the microstructure were analyzed to understand how they relate to the physical and chemical properties of these films. Specifically, we found that increasing the gelatinization time decreased the film thickness, solubility, water vapor permeability, and maximum degradation temperature and increased the water content. A gradual increase in the water contact angle of the corn starch-glycerol films was observed with increasing gelatinization time. This trend is likely due to the disruptive effect of gelatinization on the crystalline and amorphous structures inherent in corn starch, resulting in reduced film crystallinity, degree of order (DO) and degree of double helix (DD).
PubMed: 38943954
DOI: 10.1016/j.foodchem.2024.140183