Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 7.208
Filter
1.
Magn Reson Med ; 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38953429

ABSTRACT

PURPOSE: To assess the potential for accelerating continuous-wave (CW) T1ρ dispersion measurement with compressed sensing approach via studying the effect that the data reduction has on the ability to detect differences between intact and degenerated articular cartilage with different spin-lock amplitudes and to assess quantitative bias due to acceleration. METHODS: Osteochondral plugs (n = 27, 4 mm diameter) from femur (n = 14) and tibia (n = 13) regions from human cadaver knee joints were obtained from commercial biobank (Science Care, USA) under Ethical permission 134/2015. MRI of specimens was performed at 9.4T with magnetization prepared radial balanced SSFP (bSSFP) readout sequence, and the CWT1ρ relaxation time maps were computed from the measured data. The relaxation time maps were evaluated in the cartilage zones for different acceleration factors. For reference, Osteoarthritis Research Society International (OARSI) grading and biomechanical measurements were performed and correlated with the MRI findings. RESULTS: Four-fold acceleration of CWT1ρ dispersion measurement by compressed sensing approach was feasible without meaningful loss in the sensitivity to osteoarthritic (OA) changes within the articular cartilage. Differences were significant between intact and OA groups in the superficial and transitional zones, and CWT1ρ correlated moderately with the reference measurements (0.3 < r < 0.7). CONCLUSION: CWT1ρ was able to differentiate between intact and OA cartilage even with four-fold acceleration. This indicates that acceleration of CWT1ρ dispersion measurement by compressed sensing approach is feasible with negligible loss in the sensitivity to osteoarthritic changes in articular cartilage.

2.
Sci Rep ; 14(1): 15106, 2024 07 02.
Article in English | MEDLINE | ID: mdl-38956156

ABSTRACT

We applied computing-as-a-service to the unattended system-agnostic miscibility prediction of the pharmaceutical surfactants, Vitamin E TPGS and Tween 80, with Copovidone VA64 polymer at temperature relevant for the pharmaceutical hot melt extrusion process. The computations were performed in lieu of running exhaustive hot melt extrusion experiments to identify surfactant-polymer miscibility limits. The computing scheme involved a massively parallelized architecture for molecular dynamics and free energy perturbation from which binodal, spinodal, and mechanical mixture critical points were detected on molar Gibbs free energy profiles at 180 °C. We established tight agreement between the computed stability (miscibility) limits of 9.0 and 10.0 wt% vs. the experimental 7 and 9 wt% for the Vitamin E TPGS and Tween 80 systems, respectively, and identified different destabilizing mechanisms applicable to each system. This paradigm supports that computational stability prediction may serve as a physically meaningful, resource-efficient, and operationally sensible digital twin to experimental screening tests of pharmaceutical systems. This approach is also relevant to amorphous solid dispersion drug delivery systems, as it can identify critical stability points of active pharmaceutical ingredient/excipient mixtures.


Subject(s)
Excipients , Polysorbates , Excipients/chemistry , Polysorbates/chemistry , Vitamin E/chemistry , Surface-Active Agents/chemistry , Pyrrolidines/chemistry , Molecular Dynamics Simulation , Thermodynamics , Hot Melt Extrusion Technology/methods , Vinyl Compounds
3.
Bioresour Technol ; 406: 131071, 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38971391

ABSTRACT

The isomerization of glucose is a crucial step for biomass valorization to downstream chemicals. Herein, highly dispersed MgO doped biochar (BM-0.5@450) was prepared from rice straw via a solvent-free ball milling pretreatment and pyrolysis under nitrogen conditions. The nano-MgO doped biochar demonstrated enhanced conversion of glucose in water at low temperatures. A 31 % yield of fructose was obtained from glucose over BM-0.5@450 at 50 °C with 80.0 % selectivity. At 60 °C for 140 min, BM-0.5@450 achieved a 32.5 % yield of fructose. Compared to catalyst synthesized from conventional impregnation method (IM@450), the BM-0.5@450 catalyst shows much higher fructose yields (32.5 % vs 25.9 %), which can be attributed to smaller crystallite size of MgO (11.32 nm vs 19.58 nm) and homogenous distribution. The mechanism study shows that the activated MgOH+·OH- group by water facilitated the deprotonation process leading to the formation of key intermediate enediol.

5.
World J Diabetes ; 15(6): 1280-1290, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38983825

ABSTRACT

BACKGROUND: Peripheral vascular disease (PVD) is a common complication of type 2 diabetes mellitus (T2DM). Patients with T2DM have twice the risk of PVD as nondiabetic patients. AIM: To evaluate left ventricular (LV) systolic function by layer-specific global longitudinal strain (GLS) and peak strain dispersion (PSD) in T2DM patients with and without PVD. METHODS: Sixty-five T2DM patients without PVD, 57 T2DM patients with PVD and 63 normal controls were enrolled in the study. Layer-specific GLS [GLS of the epimyocardium (GLSepi), GLS of the middle myocardium (GLSmid) and GLS of the endocardium (GLSendo)] and PSD were calculated. Receiver operating characteristic (ROC) analysis was performed to calculate the sensitivity and specificity of LV systolic dysfunction in T2DM patients with PVD. We calculated Pearson's correlation coefficients between biochemical data, echocardiographic characteristics, and layer-specific GLS and PSD. RESULTS: There were significant differences in GLSepi, GLSmid and GLSendo between normal controls, T2DM patients without PVD and T2DM patients with PVD (P < 0.001). Trend tests revealed a ranking of normal controls > T2DM patients without PVD > T2DM patients with PVD in the absolute value of GLS (P < 0.001). PSD differed significantly between the three groups, and the trend ranking was as follows: normal controls < T2DM patients without PVD < T2DM patients with PVD (P < 0.001). ROC analysis revealed that the combination of layer-specific GLS and PSD had high diagnostic efficiency for detecting LV systolic dysfunction in T2DM patients with PVD. Low-density lipoprotein cholesterol was positively correlated with GLSepi, GLSmid and PSD (P < 0.05), while LV ejection fraction was negatively correlated with GLSepi, GLSmid and GLSendo in T2DM patients with PVD (P < 0.01). CONCLUSION: PVD may aggravate the deterioration of LV systolic dysfunction in T2DM patients. Layer-specific GLS and PSD can be used to detect LV systolic dysfunction accurately and conveniently in T2DM patients with or without PVD.

6.
World J Diabetes ; 15(6): 1272-1279, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38983828

ABSTRACT

BACKGROUND: Cardiovascular disease has been the leading cause of morbidity and mortality for type 2 diabetes mellitus (T2DM) patients over the last decade. AIM: To determine whether layer-specific global longitudinal strain (GLS) combined with peak strain dispersion (PSD) can be used to assess left ventricle (LV) myocardium systolic dysfunction in T2DM patients or without hypertension (HP). METHODS: We enrolled 97 T2DM patients, 70 T2DM + HP patients and 101 healthy subjects. Layer-specific GLS and PSD were calculated by EchoPAC software in apical three-, four- and two-chamber views. GLS of the epimyocardial, middle-layer and endomyocardial (GLSepi, GLSmid, and GLSendo) were measured and recorded. Receiver operating characteristic analysis was performed to detect LV myocardium systolic dysfunction in T2DM patients. RESULTS: There were significant differences in GLSepi, GLSmid, GLSendo, and PSD between healthy subjects, T2DM patients and T2DM patients with HP (P < 0.001). Trend tests yielded the ranking of healthy subjects > T2DM patients > T2DM with HP patients in the absolute values of GLSepi, GLSmid and GLSendo (P < 0.001), while PSD was ranked healthy subjects < T2DM < T2DM with HP (P < 0.001). Layer-specific GLS and PSD had high diagnostic efficiency for detecting LV myocardium systolic dysfunction in T2DM patients, however, the area under the curve (AUC) for layer-specific GLS and PSD combined was significantly higher than the AUCs for the individual indices (P < 0.05). CONCLUSION: Layer-specific GLS and PSD were associated with LV myocardium systolic dysfunction in T2DM patients, T2DM patients with HP. T2DM patients with HP have more severe LV myocardium systolic dysfunction than T2DM patients without HP and normal control patients. The combination of layer-specific GLS and PSD may provide additional prognostic information for T2DM patients with or without HP.

7.
Pharm Dev Technol ; : 1-7, 2024 Jul 13.
Article in English | MEDLINE | ID: mdl-38995216

ABSTRACT

The appearance of an extrudate formulation was monitored during hot-melt extrusion (HME) continuous manufacturing over 3 days. The formulation matrix consisted of a polymeric component, copovidone, and a low molecular weight surfactant, polysorbate 80. Based on studies prior to the continuous manufacturing, the desired appearance of the target extrudate is translucent. Although process parameters such as feed rate and screw speed were fixed during the continuous manufacturing, the extrudate appearance changed over time from turbid to translucent. For root-cause investigation, the extrudates were analyzed offline by differential scanning calorimetry (DSC) and advanced polymer chromatography (APC™). Although the polysorbate 80 content of both turbid and translucent extrudates was within target, the glass transition temperature of the turbid extrudate was 2 °C above expected value. The observed turbidity was traced to lot-to-lot variability of the polysorbate 80 used in the continuous manufacturing, where APC™ analysis revealed that the relative content of the low molecular weight component varied from 23% to 27% in correlation with the evolution from turbid to translucent extrudates. This work stresses the importance of taking feeding material variability into account during continuous manufacturing.

8.
Environ Pollut ; : 124475, 2024 Jun 29.
Article in English | MEDLINE | ID: mdl-38950843

ABSTRACT

Air pollution in urban environments exhibits large spatial and temporal variations due to high heterogeneous air flow and emissions. To address the complexity of local air pollutant dynamics, a comprehensive large-eddy simulation using the PALM model system v6.0 was conducted. The distribution of flow and vehicle emitted aerosol particles in a realistic urban environment in Malmö, Sweden, was studied and evaluated against on-site measurements made using portable instrumentation on a spring morning in 2021. The canyon transport mechanisms were investigated, and the convective and turbulent mass-transport rates compared to clarify their role in aerosol transport. The horizontal distribution of aerosols showed acceptable evaluation metrics for both mass and number. Flow and pollutant concentrations were more complex than those in idealized street canyon networks. Vertical turbulent mass-transport rate was found to dominate the mass transport process compared with the convective transport rate, contributing more than 70% of the pollutant transport process. Our findings highlight the necessity of examining various aerosol metric due their distinct dispersion behaviour. This study introduces a comprehensive high-resolution modelling framework that accounts for dynamic meteorological and aerosol background boundary conditions, real-time traffic emission, and detailed building features, offering a robust toll for local urban air quality assessment.

9.
Cardiovasc Diagn Ther ; 14(3): 388-401, 2024 Jun 30.
Article in English | MEDLINE | ID: mdl-38975003

ABSTRACT

Background: Previous studies have suggested that adequate myocardial reperfusion after percutaneous coronary intervention (PCI) can improve the inhomogeneity of myocardial repolarization. However, it remains unclear whether no-reflow (NR) following emergency PCI involves disadvantages related to ventricular repolarization indices. The present study aimed to determine the effect of NR on QT dispersion (QTd) in patients with ST-segment elevation myocardial infarction (STEMI) and to evaluate the prognostic value of the relative reduction of QTd on ventricular arrhythmia events (VAEs). Methods: A prospective case-control study was conducted. According to the inclusion criteria, 275 patients with STEMI who underwent primary PCI treatment at the First People's Hospital of Anqing affiliated to Anhui Medical University from January 2020 to May 2023 were enrolled. According to whether NR occurred during PCI, these patients were divided into two groups: an NR group and a non-NR group. Subsequently, the QT intervals were measured before and at 12 hours after PCI. Afterward, the QTd, corrected QTd (QTcd), and the relative reduction of QTd and QTcd 12 hours pre- and postprocedure (ΔQTd-R and ΔQTcd-R, respectively) were calculated. Finally, multivariable logistic regression analysis was performed to predict the risk of VAE occurrence. Results: In the non-NR group, there was a significant decrease from baseline in postprocedure QTd (48±17 vs. 73±22 ms; P=0.009) and QTcd (54±19 vs. 80±23 ms; P=0.01); in contrast, the NR group showed no significant difference in QTd (64±20 vs. 75±23 ms; P=0.58) or QTd (70±22 vs. 82±26 ms; P=0.45). Furthermore, the ΔQTd-R and ΔQTcd-R were both lower in the NR group than in the non-NR group (P<0.05); however, the rate of VAEs was higher in the NR group than in the non-NR group (15.2% vs. 6.2%; P=0.02). The multivariable logistic regression analysis results revealed that each increase of 12% in ΔQTcd-R was an independent predictor of VAEs (odds ratio: 0.547; 95% confidence interval: 0.228-0.976). Conclusions: The NR phenomenon following primary PCI in patients with STEMI leads to the defective recovery of QTd and QTcd. Furthermore, ΔQTcd-R can be viewed as an effective indicator for evaluating the myocardial repolarization inhomogeneity, and short-term clinical outcomes.

10.
Heliyon ; 10(12): e32389, 2024 Jun 30.
Article in English | MEDLINE | ID: mdl-38975180

ABSTRACT

Despite being an innocuous commensal of human skin and mucous membranes, Staphylococcus epidermidis, infects surgical wounds and causes infections through biofilm formation. This study evaluates, in a time-dependent experiment, the self-dispersion of S. epidermidis CIP 444 biofilm when formed on borosilicate glass (hydrophilic) and polystyrene (hydrophobic) surfaces, using physical and molecular approaches. During a seven-day period of incubation, absorbance measurement revealed a drop in biofilm optical density on both studied surfaces on day 4 (0.043-0.035 nm/cm2, polystyrene), (0.06-0.053 nm/cm2, borosilicate glass). Absorbance results were correlated with crystal violet staining that showed a clear detachment from day 4. The blue color increases again on day 7, with an increase in biofilm optical density indicating the regeneration of the biofilm. Changes in gene expression in the S. epidermidis biofilm were assessed using a real-time reverse transcription-polymerase chain reaction. High expression of agr genes was detected on days 4 and 5, confirming our supposition of dispersion in this period, autolysin genes like atlE1 and aae were upregulated from day 3 until day 6 and the genes responsible for slime production and biofilm accumulation, were upregulated on days 4, 5, and 6 (ica ADBC) and on days 5, 6 and 7 (aap), indicating a dual process taking place. These findings suggest that S. epidermidis CIP 444 biofilms disperse at day 4 and reform at day 7. Over the course of the seven-day investigation, 2-ΔΔCt results showed that some genes in the biofilm were dramatically enhanced while others were significantly decreased as compared to planktonic ones.

11.
Adv Sci (Weinh) ; : e2405378, 2024 Jul 08.
Article in English | MEDLINE | ID: mdl-38976553

ABSTRACT

A 3D bulk metamaterial (MM) containing amorphous multilayered split-ring resonators is proposed, fabricated, and evaluated. Experimentally, the effective refractive index is engineered via the 3D bulk MM, with a contrast of 0.118 across the frequency span from 0.315 to 0.366 THz and the index changing at a slope of 2.314 per THz within this frequency range. Additionally, the 3D bulk MM exhibits optical isotropy with respect to polarization. Moreover, the peak transmission and optical dispersion are tailored by adjusting the density of the split-ring resonators. Compared to reported conventional approaches for constructing bulk MMs, this approach offers advantages in terms of the potential for large-scale manufacturing, the ability to adopt any shape, optical isotropy, and rapid optical dispersion. These features hold promise for dispersive optical devices operating at THz frequencies, such as high-dispersive prisms for high-resolution spectroscopy.

12.
Brain Res ; : 149114, 2024 Jul 06.
Article in English | MEDLINE | ID: mdl-38977237

ABSTRACT

OBJECTIVES: Previous studies have shown that microstructural alterations in white matter (WM) could contribute to the symptom manifestation and support the dysconnectivity hypothesis in schizophrenia patients. These alterations were pervasive, non-specific, and reported inconsistently across the literature. This study aimed to specifically investigate the microstructure alterations of the posterior limb of the internal capsule (PLIC) in first-episode, drug-naive schizophrenia patients. Utilizing a multicompartmental biophysical model, we further explored the correlation between these alterations and syndrome scale scores. METHODS: Thirty-two individuals with first-episode, drug-naive schizophrenia (FES) and thirty demographically matched healthy controls were enrolled. High-resolution multi-shell diffusion MRI data were collected, followed by the application of a three-compartment Neurite Orientation Dispersion and Density Imaging (NODDI) model to scrutinize the alterations in white matter microstructure. Changes in sensory and motor fibers within the PLIC were specifically focused on. Additionally, the correlation between these pathological changes and scores on the Positive and Negative Syndrome Scale (PANSS) was investigated. RESULTS: The Neurite density index (NDI) in the left PLIC was significantly lower in FES patients compared to healthy individuals, and positively correlated with PANSS positive syndrome scores (r = 0.0379, p = 0.046). In the sensory component (left superior thalamic radiation within PLIC, STR_P), the NDI was significantly elevated (p < 0.0001). Conversely, the NDI in the motor component (left corticospinal tract within PLIC, CST_P) was reduced (p = 0.007) in FES patients compared to healthy individuals, and strongly correlated with PANSS positive syndrome scores (p < 0.020) and PANSS total scores (p < 0.045). Moreover, the NDI deviation of STR from total PLIC (fSTR_P) and NDI deviation in STR_P and CST_P compared to PLIC region (fPLIC) were significantly higher in FES patients than in healthy controls (p < 0.00001), with an area under the curve (AUC) of fPLIC reaching 0.872. CONCLUSION: The study's findings provided new insights into the discrepancy of white matter microstructure changes associated with the sensory and motor fibers in the PLIC region in FES patients. These results contribute to the growing body of evidence suggesting that WM microstructural alterations play a critical role in schizophrenia pathophysiology.

13.
Int J Pharm X ; 7: 100259, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38974024

ABSTRACT

Forty-eight (48) drug products (DPs) containing amorphous solid dispersions (ASDs) have been approved by the U.S. Food and Drug Administration in the 12-year period between 2012 and 2023. These DPs comprise 36 unique amorphous drugs. Ten (10) therapeutic categories are represented, with most DPs containing antiviral and antineoplastic agents. The most common ASD polymers are copovidone (49%) and hypromellose acetate succinate (30%), while spray drying (54%) and hot melt extrusion (35%) are the most utilized manufacturing processes to prepare the ASD drug product intermediate (DPI). Tablet dosage forms are the most common, with several capsule products available. Line extensions of several DPs based on flexible oral solids and powders for oral suspension have been approved which provide patient-centric dosing to pediatric and other patient populations. The trends in the use of common excipients and film coating types are discussed. Eighteen (18) DPs are fixed-dose combinations, and some contain a mixture of amorphous and crystalline drugs. The DPs have dose/unit of amorphous drug ranging from <5 mg up to 300 mg, with the majority being ≤100 mg/unit. This review details several aspects of DPI and DP formulation and manufacturing of ASDs, as well as trends related to therapeutic category, dose, and patient-centricity.

14.
Sci Total Environ ; 946: 174494, 2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38969111

ABSTRACT

Gypsum plays a prominent role in agriculture, being considered an effective alternative to alleviate subsurface acidity due to its higher solubility and containing sulfur. However, another significant aspect is which pose long-term risks of groundwater contamination due to excessive applications of salts, pesticides, and other chemicals that will be leached, or even soil chemical depletion. So far, no study has focused on understanding the impacts of the atmospheric gypsum plume originating from gibbsite mining and processing on the leaching of soil bases and chemical degradation surrounding these sites. In this study, we evaluated the behavior of chemical characteristics in soil profiles distributed along the dispersion of the atmospheric plume and in areas without interference from the industrial sector in the state of Maranhão, Northeast Brazil. Fifty-three sampling points were collected at 7 locations based on the dispersion of the dust plume through wind drift. Each sampling point was represented by three composite soil samples at depths of 0.0-0.20, 0.40-0.60, and 1.00-1.20 m, where the chemical soil characteristics were evaluated. The average levels of Ca, Mg, and K in the studied layers are classified as low, with minimum values below the method's detection limit, and they also show imbalance due to higher concentrations of Ca in the surface layer in areas affected by atmospheric dispersion. The sum and saturation of bases at all depths are classified as low. Higher aluminum saturation values were observed in the deeper soil layers. The gypsum dust altered the soil's chemical characteristics at the evaluated depths; therefore, it is necessary to seek means to mitigate gypsum dust release during gibbsite extraction and processing and ensure that the soils in areas near these enterprises maintain their natural characteristics.

15.
Neurophysiol Clin ; 54(5): 102991, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38970866

ABSTRACT

OBJECTIVE: MScanFit motor unit number estimation (MUNE) is a sensitive method for detecting motor unit loss and has demonstrated high reproducibility in various settings. In this study, our aim was to assess the outputs of this method when the nerve conduction distance is increased. METHODS: MScanFit recordings were obtained from the abductor digiti minimi muscle of 20 healthy volunteers. To evaluate the effect of nerve conduction distance, the ulnar nerve was stimulated from the wrist and elbow respectively. Reproducibility of MUNE, compound muscle action potential (CMAP), and other motor unit parameters were assessed using intraclass correlation coefficients (ICCs). RESULTS: Motor unit numbers obtained from stimulation at the wrist and elbow did not significantly differ and exhibited strong consistency in the ICC test (120.3 ± 23.7 vs. 118.5 ± 27.9, p > 0.05, ICC: 0.88). Similar repeatability values were noted for other parameters. However, the Largest Unit (%) displayed notable variability between the two regions and exhibited a negative correlation with nerve conduction distance. CONCLUSION: Our findings indicate that MScanFit can consistently calculate motor unit numbers and most of its outputs without substantial influence from nerve conduction distance. Exploring MScanFit's capabilities in various settings could enhance our understanding of its strengths and limitations for extensive use in clinical practice.

16.
Electromagn Biol Med ; 43(3): 187-203, 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38990565

ABSTRACT

To enhance our understanding of electroporation and optimize the pulses used within the frequency range of 1 kHz to 100 MHz, with the aim of minimizing side effects such as muscle contraction, we introduce a novel electrical model, structured as a 2D representation employing exclusively lumped elements. This model adeptly encapsulates the intricate dynamics of living cells' impedance variation. A distinguishing attribute of the proposed model lies in its capacity to decipher the distribution of transmembrane potential across various orientations within living cells. This aspect bears critical importance, particularly in contexts such as electroporation and cellular stimulation, where precise knowledge of potential gradients is pivotal. Furthermore, the augmentation of the proposed electrical model with the Hodgkin-Huxley (HH) model introduces an additional dimension. This integration augments the model's capabilities, specifically enabling the exploration of muscle cell stimulation and the generation of action potentials. This broader scope enhances the model's utility, facilitating comprehensive investigations into intricate cellular behaviors under the influence of external electric fields.


In our research, we've introduced an enhanced electrical model for living cells. This model simplifies cell behavior using only basic electrical components like resistors and capacitors. It's designed to mimic the real electrical properties of cells, particularly the cell membrane, which can change in response to electricity at different frequencies, ranging from 1 kHz to 100 MHz. This frequency range is essential for studying processes like electroporation, a technique used in various medical applications.Our model is represented in a two-dimensional structure, making it a handy tool for identifying transmembrane potential distributions, a critical factor in electroporation procedures. This means we can better understand how cells react to electrical impulses, which is crucial for improving electroporation techniques.Additionally, we've extended our model to include muscle cells by incorporating the Hodgkin-Huxley model, a well-established model for understanding electrical behavior in muscle cells. This allows us to study how muscles contract when exposed to different electrical pulses, a common side effect of electroporation procedures. By examining various pulse characteristics, we can determine which ones are best for minimizing muscle contractions during electroporation.In summary, our research has led to the development of a versatile electrical model for living cells. It not only helps us understand how cells respond to electricity in the context of electroporation but also provides insights into muscle contractions and how to optimize electrical pulses for medical treatments.


Subject(s)
Action Potentials , Models, Biological , Electroporation , Cell Survival/radiation effects , Electricity , Humans
17.
ACS Appl Mater Interfaces ; 16(27): 35463-35473, 2024 Jul 10.
Article in English | MEDLINE | ID: mdl-38946100

ABSTRACT

Solution-based processing of van der Waals (vdW) one- (1D) and two-dimensional (2D) materials is an effective strategy to obtain high-quality molecular chains or atomic sheets in a large area with scalability. In this work, quasi-1D vdW Ta2Pt3Se8 was exfoliated via liquid phase exfoliation (LPE) to produce a stably dispersed Ta2Pt3Se8 nanowire solution. In order to screen the optimal exfoliation solvent, nine different solvents were employed with different total surface tensions and polar/dispersive (P/D) component (P/D) ratios. The LPE behavior of Ta2Pt3Se8 was elucidated by matching the P/D ratios between Ta2Pt3Se8 and the applied solvent, resulting in N-methyl-2-pyrrolidone (NMP) as an optimal solvent owing to the well-matched total surface tension and P/D ratio. Subsequently, Ta2Pt3Se8 nanowire thin films are manufactured via vacuum filtration using a Ta2Pt3Se8/NMP dispersion. Then, gas sensing devices are fabricated onto the Ta2Pt3Se8 nanowire thin films, and gas sensing property toward NO2 is evaluated at various thin-film thicknesses. A 50 nm thick Ta2Pt3Se8 thin-film device exhibited a percent response of 25.9% at room temperature and 32.4% at 100 °C, respectively. In addition, the device showed complete recovery within 14.1 min at room temperature and 3.5 min at 100 °C, respectively.

18.
J Headache Pain ; 25(1): 110, 2024 Jul 08.
Article in English | MEDLINE | ID: mdl-38977951

ABSTRACT

BACKGROUND: New daily persistent headache (NDPH) is a rare primary headache with unclear pathogenesis. Neuroimaging studies of NDPH are limited, and controversy still exists. Diffusion tensor imaging (DTI) is commonly used to study the white matter. However, lacking specificity, the potential pathological mechanisms of white matter microstructural changes remain poorly understood. In addition, the intricacy of gray matter structures impedes the application of the DTI model. Here, we applied an advanced diffusion model of neurite orientation dispersion and density imaging (NODDI) to study the white matter and cortical gray matter microstructure in patients with NDPH. METHODS: This study assessed brain microstructure, including 27 patients with NDPH, and matched 28 healthy controls (HCs) by NODDI. The differences between the two groups were assessed by tract-based spatial statistics (TBSS) and surface-based analysis (SBA), focusing on the NODDI metrics (neurite density index (NDI), orientation dispersion index (ODI), and isotropic volume fraction (ISOVF)). Furthermore, we performed Pearson's correlation analysis between the NODDI indicators and clinical characteristics. RESULTS: Compared to HCs, patients with NDPH had a reduction of density and complexity in several fiber tracts. For robust results, the fiber tracts were defined as comprising more than 100 voxels, including bilateral inferior fronto-occipital fasciculus (IFOF), left superior longitudinal fasciculus (SLF) and inferior longitudinal fasciculus (ILF), as well as right corticospinal tract (CST). Moreover, the reduction of neurite density was uncovered in the left superior and middle frontal cortex, left precentral cortex, and right lateral orbitofrontal cortex and insula. There was no correlation between the NODDI metrics of these brain regions and clinical variables or scales of relevance after the Bonferroni correction. CONCLUSIONS: Our research indicated that neurite loss was detected in both white matter and cortical gray matter of patients with NDPH.


Subject(s)
Diffusion Tensor Imaging , Gray Matter , White Matter , Humans , White Matter/diagnostic imaging , White Matter/pathology , Female , Gray Matter/diagnostic imaging , Gray Matter/pathology , Male , Adult , Middle Aged , Cerebral Cortex/diagnostic imaging , Cerebral Cortex/pathology , Headache Disorders/diagnostic imaging , Headache Disorders/pathology , Neurites/pathology
19.
Nanomaterials (Basel) ; 14(13)2024 Jun 26.
Article in English | MEDLINE | ID: mdl-38998699

ABSTRACT

The efficient dispersion of single-walled carbon nanotubes (SWCNTs) has been the subject of extensive research over the past decade. Despite these efforts, achieving individually dispersed SWCNTs at high concentrations remains challenging. In this study, we address the limitations associated with conventional methods, such as defect formation, excessive surfactant use, and the use of corrosive solvents. Our novel dispersion method utilizes the spontaneous charging of SWCNTs in a solvated electron system created by dissolving potassium in hexamethyl phosphoramide (HMPA). The resulting charged SWCNTs (c-SWCNTs) can be directly dispersed in the charging medium using only magnetic stirring, leading to defect-free c-SWCNT dispersions with high concentrations of up to 20 mg/mL. The successful dispersion of individual c-SWCNT strands is confirmed by their liquid-crystalline behavior. Importantly, the dispersion medium for c-SWCNTs exhibits no reactivity with metals, polymers, or other organic solvents. This versatility enables a wide range of applications, including electrically conductive free-standing films produced via conventional blade coating, wet-spun fibers, membrane electrodes, thermal composites, and core-shell hybrid microparticles.

20.
Molecules ; 29(13)2024 Jun 25.
Article in English | MEDLINE | ID: mdl-38998964

ABSTRACT

The self-association mechanisms of phenol have represented long-standing challenges to quantum chemical methodologies owing to the competition between strongly directional intermolecular hydrogen bonding, weaker non-directional London dispersion forces and C-H⋯π interactions between the aromatic rings. The present work explores these subtle self-association mechanisms of relevance for biological molecular recognition processes via spectroscopic observations of large-amplitude hydrogen bond librational modes of phenol cluster molecules embedded in inert neon "quantum" matrices complemented by domain-based local pair natural orbital-coupled cluster DLPNO-CCSD(T) theory. The spectral signatures confirm a primarily intermolecular O-H⋯H hydrogen-bonded structure of the phenol dimer strengthened further by cooperative contributions from inter-ring London dispersion forces as supported by DLPNO-based local energy decomposition (LED) predictions. In the same way, the hydrogen bond librational bands observed for the trimeric cluster molecule confirm a pseudo-C3 symmetric cyclic cooperative hydrogen-bonded barrel-like potential energy minimum structure. This structure is vastly different from the sterically favored "chair" conformations observed for aliphatic alcohol cluster molecules of the same size owing to the additional stabilizing London dispersion forces and C-H⋯π interactions between the aromatic rings. The hydrogen bond librational transition observed for the phenol monohydrate finally confirms that phenol acts as a hydrogen bond donor to water in contrast to the hydrogen bond acceptor role observed for aliphatic alcohols.

SELECTION OF CITATIONS
SEARCH DETAIL
...