Maximal Separation Research Articles

Neuron configuration enhances the synchronization dynamics in ring networks with heterogeneous firing patterns

Neuron synchronization is fundamental for brain dynamics. While several efforts have been made to understand neuron coupling between tonic and bursting neurons, the position of neurons in a neural network and its relationship with synchronization is not fully understood. This work investigates the impact of neuronal heterogeneity on firing pattern transitions and synchronization in networks comprising tonic and bursting neurons. Using the Huber-Braun model, we explore two configurations: one with neurons grouped closely and another with maximal separation. Our findings reveal that while increased coupling strength generally promotes synchronization, the specific mix of neuron types and their spatial configuration crucially modulate both synchronization and firing pattern transitions, leading to phenomena such as cluster synchronization and global phase synchrony. The results indicate that the configuration with maximal separation and with mostly bursting neurons synchronizes more quickly. Firing pattern transitions are also configuration-dependent. For example, in the network with half tonic and half bursting, the configuration grouped closely undergoes diverse complex dynamics transition in the synchronized state, while the other configuration synchronize with chaotic bursting dynamics. Behaviors like cluster synchronization are observed in this network. The study underscores the significance of considering neuronal heterogeneity in understanding network dynamics.

Quantitative analysis of therapeutic peptides by CZE using multiple sample injection in hydrodynamically closed separation system.

Therapeutic peptides have emerged as an innovative and promising class of therapeutic compounds in modern medicine. Synthetic peptide analogs triptorelin and lanreotide are known for their pronounced clinical versatility and potency. In this study, we present the development and validation of novel methods based on capillary zone electrophoresis performed in hydrodynamically closed system (HCS) and paired with ultraviolet detection and repeated injection sample introduction. To the best of our knowledge, we developed the first capillary electrophoresis-based method for the determination of lanreotide, and concurrently, the first HCS method for the determination of triptorelin. Maximal separation efficiency and signal intensity were achieved using background electrolytes composed of 50mM formic acid with the addition of 0.05% (v/v) methyl-hydroxyethyl cellulose. The proposed methods exhibit favorable performance characteristics, namely, calibration curve (r2 exceeding 0.99), low limits of detection (0.25µg/mL in a water matrix and 0.5µg/mL in synthetic urine), acceptable precision (relative standard deviation ranging from 2.2% to 9.6% for intraday repeatability and between 5.2% and 14.9% for interday reproducibility), and accuracy (relative errors falling within the 91.1%-107.8% range). The method for triptorelin determination was then used for its quantification in a commercially available drug dosage form (powder for injection) and in spiked synthetic urine samples. The developed methods were also evaluated according to the novel blue applicability grade index, revealing their superior applicability. The results collectively point out the potential of the proposed methods for both quality control and clinical investigations.

Пневмоцентробежная классификация дисперсных частиц в процессе переработки зерна в муку

Russia enjoys a stable demand for flour products, including those obtained by the dry method of starch and gluten production. This study featured pneumocentrifugal parameters of fine particles in a spiral separator that classified milled grain into fractions, separated the solid phase from air, and identified the high-protein flour fraction in the flow. 
 Pneumatically classified flour was subjected to mathematical modeling and experimental research. The analysis of movement and deposition of particles in the working area covered particle mass, density, air-flow rate, and geometry, as well as their effect on the trajectory of particle movement and deposition. The experiment also involved the effect of air-flow rate and air-mix concentration on the classification efficiency.
 Particles from various grinding and break systems demonstrated classification modes that differed in soaring rate, size, and density. At an air-flow rate of 6–8 m/s, turn 1 of the spiral separator had the ratio of the internal coil radius to the inner pipe diameter as r1/dpipe = 7.9; it was r1/dpipe = 7 on turn 2 and fell down to r1/dpipe = 6.25 on turn 3; for all subsequent turns, the ratio was r1/dpipe < 5. Under these conditions, the fraction reached 160 µm and included small high-protein flour fractions with a particle size of 17–20 µm. The percentage of product accumulated on turns 1, 2, and 3 was 80, 12, and 8%, respectively. The maximal product separation efficiency of the third drain system was as high as 98% at an input rate of 6 m/s. The maximal separation efficiency for premium flour reached 99.2% at an input rate of 4.2 m/s.
 The separator proved efficient in classifying wheat grain flour into fractions as it was able to separate high-protein fraction and dispersed particles from the air flow. The separator could be used both as an independent device and as part of a complex technological scheme at the stage of pneumatic separators and unloaders.

Experimental study on leakage characteristics of gas-liquid two-phase flow in a horizontal pipe

Oil and gas pipeline leakage accidents caused by aging and third-party damage have increased, resulting in polluting the ecological environment and jeopardizing life and property safety. A detailed and systematic investigation on the leak characteristics of oil and gas two-phase pipelines is significantly urgent. The leak experiments were performed on a horizontal tube with a diameter of 32 mm. There was a 3 mm round leakage hole at the bottom of the tube. The distance of the leakage hole from the pipe inlet was 4.8 m. Three inlet flow patterns, including stratified flow, slug flow, and annular flow via adjusting the gas superficial velocity (1.73 m/s ≤ USG ≤ 24.19 m/s) and liquid superficial velocity (0.017 m/s ≤ USL ≤ 0.415 m/s), were obtained. The conclusions point out that the type of leakage, whether it is mainly liquid or both gas and liquid, depends on the USG. The degree of phase separation in stratified flow is the greatest among the three inlet flow patterns, with a maximal phase separation efficiency (η) of 0.403. Slug flow has the least phase separation degree. Interestingly, the η is directly proportional to the inlet mass fraction only for slug flow. The harmonic frequency that appeared in the power spectral density curves for the pressure difference of leakage hole in slug flow, indicates that leakage is not a standard periodic event. The liquid velocity loss is primarily related to the gas leakage mechanism. These findings can provide new insights into two-phase pipeline leak detection and accident consequence prediction.

Novel mesh suture may resist bone cutting seen with wire-based sternal closures.

Sternal dehiscence is frequently associated with wire-based closures cutting through fragile bone, allowing sternal motion, separation, and infection. We investigated whether bone cutting could be limited by using a newly available mesh suture with improved force distribution. Five sternal models were closed using 8 interrupted single sternal wires, double sternal wires, braided poly(ethylene terephthalate) sutures, single-wrapped mesh sutures, or double-wrapped mesh sutures. To simulate chest-wall forces, closed sternal models were pulled apart using 1020N of axial force applied incrementally. Double sternal wire and double-wrapped mesh suture were further compared by closing 3 new models with each material and subjecting these models to cyclic loading cycles, simulating breathing and coughing. Image analysis of needle hole size measured "bone cutting" by each closure material and sternal distraction as a function of force. All models exhibited maximal separation at the xiphoid. During axial loading, needle hole size increased 7.2% in the double-wrapped mesh suture model and 9.2% in the double-wire model. Single-wrapped mesh suture, single wires, and braided poly(ethylene terephthalate) extended needle hole size by 6.7%, 47.0%, and 168.3% of original size, respectively. The double-wire model resisted sternal distraction best, separating 0.285cm at the xiphoid. During cyclic loading, mesh suture exhibited significantly less bone cutting (P=.02) than double wire, with comparable levels of sternal separation (P=.07). Mesh suture may resist bone cutting seen in sternal wire closure in bone models with comparable distraction to currently used sternal closure methods.

Developing multidimensional participation profiles after traumatic brain injury: a TBI model systems study

Purpose. To characterize societal participation profiles after moderate-severe traumatic brain injury (TBI) along objective (Frequency) and subjective (Satisfaction, Importance, Enfranchisement) dimensions. Materials and Methods. We conducted secondary analyses of a TBI Model Systems sub-study (N = 408). Multiaxial assessment of participation included the Participation Assessment with Recombined Tools-Objective and -Subjective questionnaires (Participation Frequency and Importance/Satisfaction, respectively) and the Enfranchisement Scale. Participants provided responses via telephone interview 1–15 years post-injury. Multidimensional participation profiles (classes) were extracted using latent profile analysis. Results. A 4-class solution was identified as providing maximal statistical separation between profiles and being clinically meaningful based on profile demographic features. One profile group (48.5% of the sample) exhibited the “best” participation profile (High Frequency, Satisfaction, Importance, and Enfranchisement) and was also the most advantaged according to socioeconomic indicators. Other profile groups showed appreciable heterogeneity across participation dimensions. Age, race/ethnicity, education level, ability to drive, and urbanicity were features that varied between profiles. Conclusions. Societal participation is a critical, but inherently complex, TBI outcome that may not be adequately captured by a single index. Our data underscore the importance of a multidimensional approach to participation assessment and interpretation using profiles. The use of participation profiles may promote precision health interventions for community integration. Implications for Rehabilitation Our study found unidimensional measures of societal participation in traumatic brain injury (TBI) populations that focus exclusively on frequency indicators may be overly simplistic and miss key subjective components of participation Taking a multidimensional perspective, we documented four meaningfully distinct participation subgroups (including both objective and subjective dimensions of societal participation) within the TBI rehabilitation population Multidimensional profiles of participation may be used to group individuals with TBI into target groups for intervention (e.g., deeper goal assessment for individuals who do not rate standard participation activities as important, but also do not participate and do not feel enfranchised).

Prefrontal NIRS signal is unaffected by forehead Doppler flux during incremental cycling exercise.

Near-infrared spectroscopy (NIRS) is used to measure tissue concentrations of oxyhemoglobin (O2 Hb) and deoxyhemoglobin (HHb). In the context of exercise, NIRS confers a higher signal-to-noise ratio than other neuroimaging techniques. However, part of the signal may be influenced by thermoregulatory hyperemia in the superficial cutaneous capillaries of the forehead. The degree to which NIRS signals during exercise reflect cerebral or extracerebral hemodynamic changes is a continuing source of controversy. However, the influence of skin blood flow may be attenuated depending on the NIRS technique (e.g., frequency domain machines with maximal optode separation distances >3.5 cm). The purpose of this study was to compare the changes in forehead skin blood flow and cerebral hemoglobin concentration during incremental exercise versus direct vasodilation of the forehead skin induced by gradual local heating. Thirty participants (12 females, 18 males; age: 20.8 ± 3.2 years; body mass index: 23.8 ± 3.7 kg·m-2 ) participated in the study. Forehead skin blood flow was quantified laser Doppler flux and absolute concentrations of cerebral O2 Hb and HHb were measured by NIRS. Local heating significantly increased the Doppler flux signal across time and these changes were significantly correlated with skin temperature. During incremental exercise, skin temperature, Doppler flux, O2 Hband HHb increased however, the only significant change that was consistently correlated with Doppler flux was skin temperature. Therefore, a significant change in forehead skin blood flow may not significantly the NIRS hemoglobin data, depending on the type of NIRS device used.

Seedless fruit in Annona squamosa L. is monogenic and conferred by INO locus deletion in multiple accessions

Key messageInheritance of the presence/absence of seeds in Annona squamosa is mediated by a single fully recessive gene and is caused by a deletion of the INNER NO OUTER (INO) locus.For some fruits, seedless varieties are desirable for consumption and processing. In the sugar apple tree (Annona squamosa L.), the seedless trait in the Thai seedless (Ts) and Brazilian seedless (Bs) accessions was associated with defective ovules and an apparent deletion of the INNER NO OUTER (INO) ovule development gene locus. Segregation analysis of F2 and backcross descendants of crosses of Bs to fertile wild-type varieties in this species with a multi-year generation time showed that seedlessness was recessive and controlled by a single locus. Comparison of whole genome sequence of a wild-type plant and a third accession, Hawaiian seedless (Hs), identified a 16 kilobase deletion including INO in this line. Ts and Bs lines were shown to have an identical deletion, indicating a common origin from a single deletion event. Analysis of microsatellite markers could not preclude the possibility that all three seedless accessions are vegetatively propagated clones. The sequence of the deletion site enabled a codominant assay for the wild-type and mutant genes allowing observation of complete cosegregation of the seedless/defective ovule phenotype with the INO deletion, showing maximal separation of less than 3.5 cM. The observed deletion is the only significant difference between the wild-type and Hs line over 587 kilobases, likely encompassing much more than 3.5 cM, showing that the deletion is the cause of seedless trait. The codominant markers and obtained progenies will be useful for introgression of the seedless trait into elite sugar apple lines and into other Annonas through interspecific crossings.

Extraction equilibrium of vanillic acid using natural solvents

Vanillic acid is a natural bioactive phenolic compound widely used in the food and pharmaceutical industries for its pleasant fragrance, but it is gaining attention due to its pharmacological activities having potential applications in the field of medicine. For a long time, conventional organic solvents have been extensively used in liquid-liquid extraction processes because of their excellent physiochemical properties, but at the same time, their toxic and hazardous nature cannot be ignored. Hence, the use of alternate green or non-toxic solvents with less environmental impact is needed. In the current study, a few non-toxic solvents like mustard oil, groundnut oil, sunflower oil, rice bran oil, and sesame oil have been investigated to study their efficiency for the extraction of vanillic acid from the aqueous phase. The performance of the process was elucidated using the terms separation efficiency (%E) and distribution coefficient (KD). The maximal separation efficiency of 57.99% and distribution coefficient of 1.38 were found for sesame oil at 0.001 mol.L−1, showing better performance than the other non-toxic solvents considered for this study. Furthermore, 90% efficiency may be achieved in a multiple stage extraction process with the advantage of the non-toxic nature of solvents.

Noisy intermediate-scale quantum computing algorithm for solving an n -vertex MaxCut problem with log( n ) qubits

Quantum computers are devices, which allow more efficient solutions of problems as compared to their classical counterparts. As the timeline to developing a quantum-error corrected computer is unclear, the quantum computing community has dedicated much attention to developing algorithms for currently available noisy intermediate-scale quantum computers (NISQ). Thus far, within NISQ, optimization problems are one of the most commonly studied and are quite often tackled with the quantum approximate optimization algorithm (QAOA). This algorithm is best known for computing graph partitions with a maximal separation of edges (MaxCut), but can easily calculate other problems related to graphs. Here, I present a novel quantum optimization algorithm, which uses exponentially less qubits as compared to the QAOA while requiring a significantly reduced number of quantum operations to solve the MaxCut problem. Such an improved performance allowed me to partition graphs with 32 nodes on publicly available 5 qubit gate-based quantum computers without any preprocessing such as division of the graph into smaller subgraphs. These results represent a 40% increase in graph size as compared to state-of-art experiments on gate-based quantum computers such as Google Sycamore. The obtained lower bound is 54.9% on the solution for actual hardware benchmarks and 77.6% on ideal simulators of quantum computers. Furthermore, large-scale optimization problems represented by graphs of a 128 nodes are tackled with simulators of quantum computers, again without any predivision into smaller subproblems and a lower solution bound of 67.9% is achieved. The study presented here paves way to using powerful genetic optimizer in synergy with quantum computers.Received 2 March 2022Accepted 20 December 2022DOI:https://doi.org/10.1103/PhysRevResearch.5.L012021Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasQuantum algorithmsQuantum Information

Impact of Layered Perovskite Oxide La0.85Yb0.15AlO3 on Structure and Transport Properties of Polyetherimide.

This study aims to improve properties of Ultem® polyetherimide (PEI) by incorporating up to 2 wt% additives of the perovskite oxide La0.85Yb0.15AlO3 (LYA). The structure of dense PEI/LYA films was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) in combination with an analysis of their elemental composition using energy-dispersive spectroscopy (EDS). The PEI/LYA films exhibit a two-layer structure. Contact angle measurements revealed hydrophilization of the membrane surface enriched with the perovskite. The transport properties were tested via gas separation and pervaporation processes. The separation selectivity of He/N2 and O2/N2 gas pairs increased with the growth of the LYA content in the membranes. Pervaporation of a methanol(MeOH)-cyclohexane(CH) mixture was effective due to the high sorption of MeOH in the PEI/LYA membranes. The maximal pervaporation separation index was found for the PEI/LYA(2%) membrane.

Enhanced ethanol pervaporative selectivity of polydimethylsiloxane membranes by incorporating with graphene oxide@silica core‐shell structure

AbstractA graphene oxide@silica core‐shell structure (GO@silica) was prepared and embedded into the polydimethylsiloxane (PDMS) to fabricate mixed matrix membranes (MMMs). Meanwhile, (3,3,3‐trifluoropropyl)triethoxysilane (TFTS) was employed to improve the compatibility between PDMS and GO@silica and create a hydrophobic membrane surface for improving the ethanol pervaporative performance. The scanning electron microscope (SEM) result showed that the resultant PDMS/GO@silica MMMs were smooth and defect‐free. Meanwhile, the increase in hydrophobicity, swelling degree, and PV performance was achieved because of the incorporation of the modified GO@silica. The maximal separation factor of 11.43 coupled with a high permeation flux of 223 g·m−2·h−1 was observed when separating a 10 wt. % ethanol/water mixture at 30°C. Moreover, the MMMs displayed a stable PV performance during a 168‐h continuous operation.

Продуктивність та якісні показники яєць курей-несучок за зміни якісного та кількісного складу протеїну корму

Egg production characterizes not only the economic efficiency of the poultry industry, but also the effect of various factors that contribute to the realization of the genetic potential in modern high-yielding breeds, crosses and lines, or suppress its processes. These factors include nutrition, which should take into account diet balancing according to certain nutrients, as well as their qualitative indicators. Nowadays on the feed market for farm animals there are the products characterized not only by a high protein content, but also by a high digestibility. Among others, a new innovative product — a sunflower concentrate “Proglot” developed by specialists of the “Potoky” Dnipro plant is noteworthy. According to the developers, in its manufacturing a unique nanotechnologies of sunflower seed processing were used — low-temperature extraction with maximal separation of the husk. Thus, “Proglot” can be more valuable for use in poultry feeding than high-protein soybean meal, due to the absence of “anti-nutrient” substances. The article presents the results of the study aimed to find out the productive qualities of laying hens fed a highly digestible protein with a high assimilation ratio into their diet. The experiment was conducted on the Lohmann brown breed laying hens. The control group received a compound feed containing soybean meal and sunflower meal (crude protein 17%), the 1st experimental group -— soybean meal and “Proglot” (high-protein concentrate crude protein 17%), and the 2nd experimental group — high-protein concentrate only (crude protein 15%). It was established that the replacement of soybean meal in the complex ration compound feed with the innovative product “Proglot” does not cause significant intergroup differences in the body weight of the hens during the experimental period. It was shown that the maximum increase in the proportion of digestible protein in the hens’ diet and the reduction of the fraction of protein that cannot be assimilated has a positive effect on the intensity of metabolic processes in the body of laying hens during the synthesis of egg components. At the same time, the poultry productivity increases: the indicators of laying hens of the 2nd research group exceeded the indicators of the analogues of the control and the 1st research groups by 2 and 4% (P<0.05), respectively, and the quality of the obtained products increases too — the absolute mass of egg protein (P<0.05) and shell strength (P<0.01).

Testing a social network approach to promote HIV self-testing and linkage to care among fishermen at Lake Victoria: study protocol for the Owete cluster randomized controlled trial

BackgroundNearly 50% of men living with HIV in many countries are unaware of their HIV status; men also have lower uptake of HIV treatment and pre-exposure prophylaxis (PrEP). In SSA, highly mobile men such as those working in fishing communities alongside Lake Victoria have low uptake of HIV testing and low rates of linkage to HIV treatment and PrEP, despite increasing availability of these services. HIV self-testing (HIVST) kits hold promise for overcoming barriers to HIV testing and linkage to services for HIV-positive and HIV-negative men. We describe here a protocol for an HIV status-neutral, social network-based approach to promote HIV testing, linkage to care and prevention, and better health outcomes, including adherence, in fishermen around Lake Victoria.MethodsUtilizing beach management unit (BMU) registries of fishermen operating in three Lake Victoria fishing communities in Siaya County, Kenya, we completed a census and social network mapping to identify close social networks of men. Network clusters identified by a socially-central lead (“promotor”) and selected to ensure maximal separation between treatment and control will be randomized. Promotors in both arms will receive basic HIV training; intervention promotors are further trained in HIVST to distribute kits to their cluster, while control promotors will distribute to their cluster vouchers for free HIVST at nearby clinics. We will test whether these promoters can enhance linkage to ART and PrEP after self-testing, thereby addressing a key limitation of HIVST. We will also measure 6- and 12-month viral load in those living with HIV and PrEP adherence among those without HIV via urine tenofovir levels as objective markers of adherence.DiscussionThis study has the potential to improve HIV health and promote HIV prevention among a hard to reach, at-risk, and highly mobile population of men in Western Kenya—a critical population in Kenya’s HIV prevention and treatment program. Further, if successful, this innovative social networks-based model could be scaled at the regional level to address HIV prevention and care among similarly at-risk populations of men in eastern Africa and inland fisheries settings across the continent.Trial registrationSelf-Test Strategies and Linkage Incentives to Improve ART and PrEP Uptake in Men, registered on February 26, 2021, registration #NCT04772469.

Acute hemodynamic impact of atrioventricular delay and left ventricular pacing vector programming in MultiPoint Pacing.

The benefits of cardiac resynchronization therapy (CRT) in heart failure patients have been shown to depend on device programming, particularly atrioventricular delay (AVD) and left ventricular (LV) pacing site selection. This study compared the hemodynamic AVD optimization for commonly used biventricular (BiV) and MultiPoint Pacing(MPP, Abbott) LV vector selection strategies. After de novo CRT-D (Abbott Quadra Assura MP) and quadripolar LV lead (Abbott Quartet) implant, acute LV pressure was measured across a range of AVDs (60-225 ms) in four pacing modes: BiV with most proximal cathode, BiV with most distal cathode, MPP using two cathodes with earliest and latest right ventricle (RV)-LV activation times, and MPP using two cathodes with maximal anatomical separation. Hemodynamic improvement was evaluated by changes in maximum LV pressure first-derivative versus RV pacing (ΔdP/dt). Twenty patients (64 years old, 68% male) completed the acute pacing protocol at six centers in China. Hemodynamic improvement versus RV pacing for BiV (proximal), BiV (Distal), MPP (electrical), and MPP (anatomical) was 22.1% ± 13.6%, 23.7% ± 13.4%, 24.5% ± 13.4%, and 25.1% ± 13.9%, respectively. The best MPP setting was marginally superior to the best BiV across all patients (25.8% ± 13.4% vs. 24.5% ± 13.1%, p = .040) and in the majority of patients (75.0% vs. 25.0%, p = .004). AVD programmed as little as 20 ms from optimum significantly reduced the ΔdP/dt benefit for all modes. The maximal hemodynamic improvement across AV delays in this population was greater with MPP than BiV. Furthermore, patient-specific AVD programming was critical in achieving the full hemodynamic response for all BiV and MPP modes.

Low rank label subspace transformation for multi-label learning with missing labels

Multi-label datasets often contain label information with missing values and recovering them is a non-trivial challenge. Several methods augment the observed label matrix by constructing auxiliary labels and learning high order label correlations. Some other techniques exploit the low rank of the label matrix to capture a mix of label correlations. Both these approaches rely on label correlations, however in different ways. In this paper, we propose a unified framework that captures the label correlations utilizing both auxiliary label matrix and the low rank constraints on estimated labels. Our model also enforces maximal separation among different label subspaces for better label differentiation. The proposed method captures local and global correlations using Low Rank label subspace transformation for Multi-label learning with Missing Labels (LRMML). The model considers an auxiliary label matrix which facilitates the missing label information recovery. Low rank on predictions ensures that local label structures are captured and the maximal inter-label subspace separation helps identify discriminatory label correlations. The proposed method builds a multi-label classification model by solving a multivariate difference of convex objective function using surrogate optimization technique and alternating minimization. Empirical results on several benchmark datasets validate the effectiveness of the proposed method against state-of-the-art multi-label learning approaches.

Relative scale separation in orbifolds of S2 and S5

In orbifold vacua containing an Sq/Γ factor, we compute the relative order of scale separation, r, defined as the ratio of the eigenvalue of the lowest-lying Γ-invariant state of the scalar Laplacian on Sq, to the eigenvalue of the lowest-lying state. For q = 2 and Γ finite subgroup of SO(3), or q = 5 and Γ finite subgroup of SU(3), the maximal relative order of scale separation that can be achieved is r = 21 or r = 12, respectively. For smooth S5 orbifolds, the maximal relative scale separation is r = 4.2. Methods from invariant theory are very efficient in constructing Γ-invariant spherical harmonics, and can be readily generalized to other orbifolds.

Recovery of rare earths in different media with novel dicarboxylate based ionic liquid and application to recycle SmCo magnets

Recovery and separation of rare earth elements was highly crucial but difficult. In this study, a well-designed new ionic liquid named as benzyltributylammonium decanedioate ([N444Bn]2[SA]) was developed to extract rare earths and separate Sm(III) from the spent SmCo magnets in acetate medium for the first time. To exhibit the superiority of acetate medium, the extraction of Nd(III) and La(III) in three different media were comparatively investigated under different conditions, including equilibrium time, initial pH of aqueous solution, rare earth concentration, extractant concentration, salting-out agent concentration and extraction temperature. The results revealed that the better extractabilities of La(III) were observed in acetate medium rather than those in chloride medium (i.e., 97.6% versus 78.6%), which may be attributed to the low-hydrated nature of acetate ions. Importantly, the back-extraction experiments indicated that 91.4% Nd(III) can be stripped from [N444Bn]2[SA] by using 1.5 mol/L HOAc, revealing the outstanding reusability of ionic liquid in the industrial separation-stripping cycles. Furthermore, the ion association mechanism was proposed to describe the extraction behavior and confirmed by the slope analysis and FT-IR characterizations in three media. In terms of the SmCoCu mixture separation, the maximal separation factor of Sm(III)/Co(II) was calculated as 3078 in simulated solution. Impressively, the recovery of Sm(III) from the actual SmCo magnets by our dicarboxylate-type ionic liquid was also successfully achieved with a recycling rate of 96.8% and a Sm(III)/Co(II) selectivity of 148, which exhibited the potential application in the separation of Sm(III) from the spent SmCo magnets.

N-Octyltrichlorosilane Modified SAPO-34/PDMS Mixed Matrix Membranes for Propane/Nitrogen Mixture Separation

In this study, zeolite molecular sieve SAPO-34/polydimethylsiloxane (PDMS) mixed matrix membranes (MMMs) were prepared to recover propane. n-Octyltrichlorosilane (OTCS) was introduced to improve compatibility between SAPO-34 and PDMS, and enhance the separation performance of the MMMs. Physicochemical properties of the MMMs were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and water contact angle (WCA). Results showed that, after modification, alkyl chains were successfully grafted onto SAPO-34 without changing its crystal structure, particles in the MMMs were evenly distributed in the base film, and the hydrophobicity of the MMMs was enhanced. Moreover, the effects of SAPO-34 filling content, operating pressure, and feed gas concentration on the separation performance was explored. This indicated that the modification with OTCS effectively enhanced the separation performance of SAPO-34/PDMS MMMs. When the filling content of modified SAPO-34 was 15%, the maximal separation factor of 22.1 was achieved, and the corresponding propane permeation rate was 101 GPU.

The dosimetric advantages of perirectal hydrogel spacer in men with localized prostate cancer undergoing stereotactic ablative radiotherapy (SABR).

To evaluate the dosimetric differences for patients receiving a perirectal hydrogel spacer (PR-HS) using SpaceOAR undergoing stereotactic ablative radiotherapy (SABR) for localized prostate cancer with the CyberKnife VSI system. Gold fiducial markers and a PR-HS was inserted in 22 consecutive patients with histologically confirmed localized prostate cancer. For planning comparison, dosimetry from the clinical plans was compared against replans based on a simulated rectum volume designed to recreate a clinically appropriate spacer-less anatomy for each patient. Both sets were planned to 36.25 Gy in 5 fractions using the treatment planning system associated with the CyberKnife VSI system. The aim was to ensure equivalent target coverage for both plans and to evaluate doses to the organs-at-risk (OARs): rectum, bladder and penile bulb. The median PR-HS implant volume was 11.2 cc (range 8.8 to 14.9 cc). The maximal median perirectal separation was 15.5 mm (10.5 to 20.7 mm). Statistically significant reductions were noted for the 3 OARs, with no statistically significant difference in planning target volumes or clinical target volume coverage. All rectal dose constraints were significantly improved in the PR-HS plans with a percentage dose difference of at least 24% (rectum V18.1Gy (%)) to 60.5% (rectum V36Gy (cc)). The bladder and penile bulb dose constraints parameters were also significantly improved: the bladder V37Gy was reduced by 17.1%, V18.1Gy was reduced by 4.2%; the penile bulb D50% was reduced by 7.7%. The use of PR-HS was able to significantly reduce planned dose to the rectum, bladder and penile bulb with SABR techniques associated with the CyberKnife VSI system.