Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 60
Filter
1.
Chemistry ; : e202400348, 2024 Apr 11.
Article in English | MEDLINE | ID: mdl-38602023

ABSTRACT

Utilizing photocatalytic method to produce hydrogen by splitting water is an efficient strategy to solve the hotspot issues of energy crisis and environmental pollution. Herein, we systematically investigate the corresponding properties of the reported Cu-bearing ternary compound monolayer CuP2Se by using the first-principle calculations. The monolayer CuP2Se has quite small cleavage energy of 0.51 J/m2, indicating it can be easily produced by the mechanical exfoliation method experimentally. In addition, it is an indirect bandgap semiconductor material which has a moderate value of 1.91 eV. The conduction band minimum (CBM) and valence band maximum (VBM) can perfectly straddle the redox potentials of water when a biaxial strain of -4% to 4% is applied, unveiling the high photocatalytic thermodynamic stability of monolayer CuP2Se in response to the effect of solvent tension. Remarkably, the monolayer CuP2Se also demonstrates significant sunlight capturing ability in the visible region. The outstanding electronic and optical properties suggest that the monolayer CuP2Se is undoubtedly a viable material for photocatalytic water splitting.

2.
Sensors (Basel) ; 24(5)2024 Mar 06.
Article in English | MEDLINE | ID: mdl-38475239

ABSTRACT

The effective identification and mitigation of non-line-of-sight (NLOS) ranging errors are essential for achieving high-precision positioning and navigation with ultra-wideband (UWB) technology in harsh indoor environments. In this paper, an efficient UWB ranging-error mitigation strategy that uses novel channel impulse response parameters based on the results of a two-step NLOS identification, composed of a decision tree and feedforward neural network, is proposed to realize indoor locations. NLOS ranging errors are classified into three types, and corresponding mitigation strategies and recall mechanisms are developed, which are also extended to partial line-of-sight (LOS) errors. Extensive experiments involving three obstacles (humans, walls, and glass) and two sites show an average NLOS identification accuracy of 95.05%, with LOS/NLOS recall rates of 95.72%/94.15%. The mitigated LOS errors are reduced by 50.4%, while the average improvement in the accuracy of the three types of NLOS ranging errors is 61.8%, reaching up to 76.84%. Overall, this method achieves a reduction in LOS and NLOS ranging errors of 25.19% and 69.85%, respectively, resulting in a 54.46% enhancement in positioning accuracy. This performance surpasses that of state-of-the-art techniques, such as the convolutional neural network (CNN), long short-term memory-extended Kalman filter (LSTM-EKF), least-squares-support vector machine (LS-SVM), and k-nearest neighbor (K-NN) algorithms.

3.
Plant Sci ; 341: 111999, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38307350

ABSTRACT

Extracellular vesicles (EVs) are membrane-enclosed nanoparticles that have a crucial role in mediating intercellular communication in mammals by facilitating the transport of proteins and small RNAs. However, the study of plant EVs has been limited for a long time due to insufficient isolation and detection methods. Recent research has shown that both plants and plant pathogens can release EVs, which contain various bioactive molecules like proteins, metabolites, lipids, and small RNAs. These EVs play essential roles in plant-microbe interactions by transferring these bioactive molecules across different kingdoms. Additionally, it has been discovered that EVs may contribute to symbiotic communication between plants and pathogens. This review provides a comprehensive summary of the pivotal roles played by EVs in mediating interactions between plants and microbes, including pathogenic fungi, bacteria, viruses, and symbiotic pathogens. We highlight the potential of EVs in transferring immune signals between plant cells and facilitating the exchange of active substances between different species.


Subject(s)
Extracellular Vesicles , Animals , Extracellular Vesicles/metabolism , RNA , Cell Communication , Plants , Symbiosis , Mammals
4.
Nano Lett ; 24(11): 3421-3431, 2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38377170

ABSTRACT

Natural killer (NK) cell-based adoptive immunotherapy has demonstrated encouraging therapeutic effects in clinical trials for hematological cancers. However, the effectiveness of treatment for solid tumors remains a challenge due to insufficient recruitment and infiltration of NK cells into tumor tissues. Herein, a programmed nanoremodeler (DAS@P/H/pp) is designed to remodel dense physical stromal barriers and for dysregulation of the chemokine of the tumor environment to enhance the recruitment and infiltration of NK cells in tumors. The DAS@P/H/pp is triggered by the acidic tumor environment, resulting in charge reversal and subsequent hyaluronidase (HAase) release. HAase effectively degrades the extracellular matrix, promoting the delivery of immunoregulatory molecules and chemotherapy drugs into deep tumor tissues. In mouse models of pancreatic cancer, this nanomediated strategy for the programmed remodeling of the tumor microenvironment significantly boosts the recruitment of NK92 cells and their tumor cell-killing capabilities under the supervision of multiplexed near-infrared-II fluorescence.


Subject(s)
Neoplasms , Pancreatic Neoplasms , Animals , Mice , Cell Line, Tumor , Neoplasms/pathology , Immunotherapy/methods , Immunotherapy, Adoptive/methods , Pancreatic Neoplasms/pathology , Killer Cells, Natural , Tumor Microenvironment
5.
Quant Imaging Med Surg ; 14(1): 264-272, 2024 Jan 03.
Article in English | MEDLINE | ID: mdl-38223066

ABSTRACT

Background: The pulsatility index (PI) derived from transcranial Doppler (TCD) assessment may represent the cerebral resistance and altered cerebral blood flow. The purpose of this study was to assess the performance of the TCD PI in correlation with wire-based fractional pressure ratio (FPR). Methods: This study included 33 patients with symptomatic atherosclerotic lesions of the extracranial and intracranial large arteries, specifically the internal carotid artery, middle cerebral artery (MCA), vertebral artery (VA) V4 segment, and basilar artery (BA), all of which exhibited luminal stenosis ranging from 50% to 70%. TCD was performed prior to angiography in order to determine the flow distal to the lesion. We performed cerebrovascular angiography with a pressure wire to measure the FPR of vessels with stenotic lesions. Bland-Altman analysis and ordinal least square (OLS) linear regression were used to quantify the correlation between PI and FPR. Results: A total of 42 TCD data points were analyzed. At the TCD locations distal to the lesions, the correlation coefficients were no less than 0.90%, with almost all P values <0.001, which indicated very strong positive correlations; the exception to this was the distal TCD for MCA segment lesions (r=0.897; P=0.015) and VA V4 segment (r=0.964; P=0.036). The Bland-Altman plot demonstrated a small difference (0.003) between the distal TCD PI and the FPR, with an acceptable 95% confidence interval [95% confidence interval (CI): 0.06-0.12]. Conclusions: The PI obtained through TCD assessment distal to the stenotic lesion exhibited a correlation with the FPR computed using pressure wire measurements.

6.
Phys Chem Chem Phys ; 26(6): 5589-5596, 2024 Feb 07.
Article in English | MEDLINE | ID: mdl-38284319

ABSTRACT

Two-dimensional magnetic materials are attracting widespread attention not only for their excellent applications in spintronic devices but also for their potential to regulate valley splitting, which is crucial for valleytronics. Herein, we design a monolayer Janus ferromagnetic semiconductor T-CrSH by using first-principles calculations. We reveal that monolayer T-CrSH has a magnetic moment of 3µB per unit cell, which is primarily contributed by the 3d orbitals of the Cr atom. Monte Carlo simulations suggest that the Curie temperature of T-CrSH is 193 K, and it can rise to 402 K when a 5% tensile strain is applied. Furthermore, the valley degeneracy of WS2 can be lifted when monolayer T-CrSH is used as a substrate. The obtained valley splitting in the conduction band is 13.7 meV and that in the valence band is 157.5 meV. In addition, the large valley polarization of 12.8 meV in the conduction band makes it easy to achieve an electron-doped valley Hall current and spin Hall current when performing in an in-plane electric field.

7.
J Am Chem Soc ; 2023 Nov 01.
Article in English | MEDLINE | ID: mdl-37910121

ABSTRACT

Near-infrared (NIR) quantum dot (QD) light-emitting diodes (LEDs) (NIR-QLEDs) for recognition and tracking applications underpin the future of night-vision technology. However, the performance of environmentally benign materials and devices has lagged far behind that of their Pb-containing counterparts. In this study, we demonstrate the superior performance of NIR-QLEDs based on efficient AgAuSe QDs with contact interface mediation. Consequently, we reveal that using cysteamine-treated QD film contact heterointerfaces can effectively eliminate contact defects in devices and preserve their excellent emissive properties. Additionally, the dipole moment orientation of the coordinated additives is inverse of the heterojunction potential difference, simultaneously blocking electrons and enhancing hole injection in operando, optimizing the LED charge injection balance. These devices exhibit a high external quantum efficiency (EQE) and a power conversion efficiency (PCE) of 15.8 and 12.7% at 1046 nm, respectively, a sub-band gap turn-on voltage of 0.9 V, and a low current density (over 10% of the EQE from 0.0017 to 0.31 mA cm-2). These are the highest EQE and PCE values ever reported for environmentally benign NIR-QLEDs. The results of this study can provide a general strategy for the practical application of QDs in electroluminescent devices.

8.
Nano Lett ; 23(21): 10058-10065, 2023 Nov 08.
Article in English | MEDLINE | ID: mdl-37877757

ABSTRACT

Currently, mainstream lanthanide probes with fluorescence located in the second near-infrared subwindow of 1500-1700 nm (NIR-IIb) are predominantly Er(III)-based nanoparticles (NPs). Here we report a newly developed NIR-IIb fluorescent nanoprobe, α-Tm NP (cubic-phase NaYF4@NaYF4:Tm@NaYF4), with an emission at 1630 nm. We activate the 1630 nm emission of Tm(III) in α-Tm NP through the large spread of the Stark split sublevels induced by the crystal-field effect of the α-NaYF4 host. Further, we systematically investigated the effect of crystalline structure of the host NaYF4 NP (cubic phase (α) or hexagonal phase (ß)), the type and concentrations of dopants (Yb(III), Tm(III), and Ca(II) ions) in the α-phase host, and the thicknesses of the interlayer and inert shell on the NIR-IIb fluorescence of Tm(III). The ultimate nanostructure presents a significant enhancement factor of the NIR-IIb photoluminescence intensity of Tm(III) up to ∼315. With this bright NIR-IIb fluorescent nanoprobe, we demonstrate high-spatial-resolution time-coursing imaging of breast cancer bone metastasis.

9.
Phys Chem Chem Phys ; 25(36): 24960-24967, 2023 Sep 20.
Article in English | MEDLINE | ID: mdl-37695166

ABSTRACT

Employing density functional theory (DFT) calculations, we explore the excellent performance of two-dimensional (2D) semiconductor In2Te5 in photocatalytic water splitting at the theoretical level. The calculated results illustrate that 2D In2Te5 is a direct band gap semiconductor with a moderate band gap value and an ultrahigh optical absorption coefficient in the visible light region. It was found that its conduction band edge is higher than the reduction potential of water (-4.44 eV), which proves that it can split water to produce hydrogen. Furthermore, its excellent hydrogen evolution activity can be tuned under an appropriate biaxial strain. In addition, 2D In2Te5 shows a remarkable photo-generated current, suggesting that electrons and holes can be separated efficiently. Our results offer a superior candidate material for realizing photocatalytic water splitting for hydrogen evolution.

10.
ACS Nano ; 17(18): 17873-17883, 2023 Sep 26.
Article in English | MEDLINE | ID: mdl-37682625

ABSTRACT

Two major aspects of functional colloidal nanoparticles are their colloidal stability (dispersion) and controlled assembly of nanoparticles into ordered structures. Simplifying colloidal nanoparticles as isotropically interacting spheres is unsuitable for small nanoparticles capped with hydrocarbon chain ligands in which the ligand-ligand interaction plays a prominent role in the assembly processes. However, experimentally characterizing the ligand shell structure in solution presents significant challenges, and computer simulations yield divergent results without effective validation. Moreover, the connection between detailed information regarding ligand shell structures and interparticle interactions, in relation to the diverse dynamical behaviors of colloidal nanoparticles, remains poorly understood. In this study, we reveal the relationship between the ligand shell structures, interparticle interactions, and dynamical behaviors of few-nm-sized near-spherical nanoparticles capped with hydrocarbon chain ligands immersed in nonpolar solvents. Our study shows a transformation of the interparticle interactions from anisotropic attractions to isotropic repulsions as a result of the change in the ligand shell structures from order to disorder caused by varying temperature and other factors. The interplay between anisotropic attractions from ligand bundles and isotropic repulsions from disordered ligands dictates the nanoparticle dynamical behaviors of dispersion, uncontrolled aggregation, and controlled assembly.

11.
Stroke Vasc Neurol ; 2023 Aug 23.
Article in English | MEDLINE | ID: mdl-37612055

ABSTRACT

BACKGROUND: At present, neurointerventional surgery requires angiographers to perform operations in the digital subtraction angiography (DSA) room. Ionising radiation and chronic joint damage are still unavoidable for angiographers. Therefore, we researched and developed a neurointerventional robot-assisted system, which is operated by angiographers in an operating room outside the DSA room. We have conducted a prospective, multicentre, randomised controlled trial to evaluate the safety and efficacy of a robot-assisted system in human cerebral angiography. In the future, this research will provide a platform for the research and development of an intelligent surgical system and bring revolutionary progress in neurointerventional surgery. METHODS: From December 2020 to December 2021, 260 patients were enrolled from three medical centres, who were randomly and equally divided into a robot-assisted system group and a clinical routine cerebral angiography group. The success rate of angiography, the rate of the catheter reaching the target vessel, the operation time, X-ray radiation exposure and the incidence of related adverse events were compared between the two groups. RESULTS: A total of 257 patients completed this trial; baseline characteristics of the two groups did not differ significantly. The success rate of angiography in both the control group and the experimental group was 100%. The rate of the catheter reaching the target vessel was 99.23% and 100.00% in the control and experimental groups, respectively. For the control versus experimental groups, the angiographic operation time was 48.59±25.60 min versus 47.94±27.49 min, respectively; the X-ray radiation dose was 735.01±554.77 mGy versus 821.65±705.45 mGy, respectively; and the incidence of adverse events was 23.44% versus 22.48%, respectively. No statistical differences were present between the two groups. CONCLUSION: The robot-assisted surgical system is more convenient for cerebral angiography and is as safe and effective as the traditional cerebral angiography.

12.
Heliyon ; 9(8): e19113, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37636373

ABSTRACT

Objective: The purpose of this study was to evaluate the effectiveness and safety of drip and ship (DS) for acute ischemic stroke (AIS) by comparing three treatment strategies: 1) patients seen at a primary stroke center, started on emergency intravenous thrombolysis and then transported to a comprehensive stroke center (drip and ship, DS); 2) patients immediately transferred to comprehensive stroke center without starting intravenous thrombolysis, for mechanical thrombectomy (non-drip and ship, non-DS); and 3) patients admitted directly to the comprehensive stroke center for assessment and subsequent bridging thrombolysis (mothership, MS). Methods: We retrospectively reviewed the data of patients that underwent mechanical thrombectomy for AIS from November 2020 to May 2022 at our institution. Patients were divided into three groups: DS, non-DS, and MS. Time course, multimodal CT features and clinical results were compared among the three groups. Results: The study included 62 patients, with 19, 18, and 25 patients in DS, non-DS, and MS groups, respectively. Baseline characteristics did not differ among the three groups. The DS group had a significantly longer median onset to groin time than the MS group (395 min vs 244 min; P < 0.001), a significantly shorter onset to primary stroke center time than the non-DS group (90 min vs 463 min; P < 0.001), and a longer primary stroke center to groin puncture time than the non-DS group (277 min vs 162 min; P = 0.002). The onset to needle time was longer in the MS group than the DS group (151.2 min vs 111.8 min; P = 0.041). The intravenous thrombolysis to puncture time was shorter in the MS group compared with DS (56 min vs 278 min; P < 0.001). No significant differences were present among groups in post-operative variables measured. Conclusions: DS is a safe and effective method, with no increased risk of postoperative complications or death compared to non-DS and MS methods. The study provides a reference for the selection of transport modes for AIS patients.

13.
J Chem Phys ; 159(1)2023 Jul 07.
Article in English | MEDLINE | ID: mdl-37417755

ABSTRACT

Hydrophilic semiconductor quantum dots (QDs) with emission in the second near-infrared window (NIR-II) have been widely studied in bioimaging applications. In such cases, QDs are usually dispersed in water. As is known, water has strong absorbance in the NIR-II region. However, investigations on the interaction between NIR-II emitters and water molecules are ignored in previous studies. Herein, we synthesized a series of mercaptoundecanoic acid-coated silver sulfide (Ag2S/MUA) QDs with various emissions that partially or completely overlapped with the absorbance of water at 1200 nm. By constructing a hydrophobic interface of cetyltrimethylammonium bromide (CTAB) with MUA on the Ag2S QDs surface via forming an ionic bond, significant enhancement of Ag2S QDs photoluminescence (PL) intensity was observed, as well as a prolonged lifetime. These findings suggest that there is an energy transfer between Ag2S QDs and water in addition to the classical resonance absorption. Transient absorption and fluorescence spectra results revealed that the increased PL intensities and lifetime of Ag2S QDs originated from the suppressed energy transfer from Ag2S QDs to the water due to the CTAB bridged hydrophobic interfaces. This discovery is important for a deeper understanding of the photophysical mechanisms of QDs and their applications.


Subject(s)
Quantum Dots , Quantum Dots/chemistry , Water/chemistry , Cetrimonium , Fluorescence , Energy Transfer
14.
J Endovasc Ther ; : 15266028231175605, 2023 Jun 02.
Article in English | MEDLINE | ID: mdl-37264807

ABSTRACT

PURPOSE: This study aimed to evaluate the impact of the pressure gradient on papilledema after stenting in patients with idiopathic intracranial hypertension (IIH) patients and venous sinus stenosis (VSS). MATERIALS AND METHODS: In this prospective cohort study, we examined 121 patients with IIH and VSS who underwent stenting. The papilledema Frisen grade at the 1-month follow-up was used as a grouping factor (favorable outcome: 0-1; unfavorable outcome: 2-5). We used multivariable logistic regression modeling to determine independent predictors of favorable outcome. The performance of the prediction model was evaluated using a receiver operating characteristic (ROC) analysis. RESULTS: A total of 96 patients had papilledema grades 0 to 1, and 25 patients had papilledema grades 2 to 5. Patients with the first group had significantly lower gradient pressures preoperatively (15.2 mmHg vs. 21.4 mmHg, p=0.001) and postoperatively (2 mmHg vs. 3.3 mmHg, p=0.002) relative to those in the second group. Multivariate analysis indicated that preoperative pressure gradient (odds ratio [OR] = 1.119; 95% confidence interval [CI] = 1.034-1.211]) and postoperative pressure gradient (OR = 1.498; 95% CI = 1.147-1.957) were independent predictors of favorable outcome. In the ROC analysis, the cut-off pressure gradient for the highest sensitivity (0.44) and specificity (0.874) was 22.75 mmHg, with a Youden's index of 0.314. Survival analysis demonstrated that patients with a preoperative pressure gradient <22.75 mmHg had more rapid improvement of papilledema than did those with a pressure gradient >22.75 mmHg (mean+SD: 2.639+0.382 [95% CI: 1.890-3.388] versus mean+SD: 3.882+0.884 [95% CI: 2.149-5.616]; p=0.004). CONCLUSION: A significant reduction in the pressure gradient appears to be strongly correlated with the success of VSS in patients with IIH. A higher preoperative pressure gradient may reduce stenting efficacy in patients with IIH. CLINICAL IMPACT: Venous sinus stenting has the potential to yield substantial clinical advantages in individuals diagnosed with idiopathic intracranial hypertension with venous sinus stenosis. Nevertheless, a heightened preoperative pressure gradient could lead to less favorable results. Thus, the early adoption of venous sinus stenting is advised to avert additional irreversible clinical deterioration among idiopathic intracranial hypertension patients with venous sinus stenosis.

15.
J Neurointerv Surg ; 2023 Jun 24.
Article in English | MEDLINE | ID: mdl-37355254

ABSTRACT

BACKGROUND: In this study, we analyzed the characteristics of different stenosis types in idiopathic intracranial hypertension (IIH) patients with venous sinus stenosis (VSS) using intravascular ultrasound (IVUS). METHODS: We retrospectively reviewed data from patients who underwent IVUS evaluation during venography or stenting procedures between January 2014 and February 2022. RESULTS: Among the 80 patients with intrinsic lesions, 47 cases were identified, including 41 single lesions and 6 multiple lesions. Single lesions consisted of 36 cases of AG, 3 cases of brain herniation, and 2 cases of septation. Multiple intrinsic lesions were found in 6 patients, with AG observed in the transverse sinus and sigmoid sinus. IVUS features varied depending on the anatomical variations of intrinsic stenosis. Additionally, among the 33 cases of extrinsic stenosis, two types were observed: unilateral compression (22 cases) and bilateral compression (11 cases), primarily affecting the transverse sinus. CONCLUSION: IVUS effectively differentiated intrinsic and extrinsic types of stenosis and identified intraluminal and mural components of intrinsic stenosis.

16.
Heliyon ; 9(4): e14504, 2023 Apr.
Article in English | MEDLINE | ID: mdl-37025769

ABSTRACT

Objectives: Glycoprotein (GP) IIb/IIIa receptor antagonists (Tirofiban) are often used as antiplatelet agents in patients undergoing interventional therapy due to acute coronary syndrome and cerebrovascular diseases. Thrombocytopenia is a common complication of GP IIb/IIIa receptor antagonist, with an incidence of 1%-5%, whereas acute profound thrombocytopenia (platelet count<20 × 109/L) is extremely rare. We reported a case of acute profound thrombocytopenia due to tirofiban treatment to inhibit platelet aggregation during and after surgery in a patient who underwent stent-assisted embolization for ruptured intracranial aneurysm. Case presentation: A 59-year-old female patient, who visited the Emergency Department of our hospital due to sudden headache, vomiting, and unconsciousness for 2 hours. Neurological examination: the patient was unconscious, the pupils on both sides had the same roundness, and the reflection on light was slow. The Hunt-Hess grade was IV. Head CT showed subarachnoid hemorrhage and Fisher's score was 3. We immediately implemented LVIS stent-assisted embolization, intraoperative heparinization, and intraoperative jailing technology to perform dense embolism on aneurysms. The patient was treated with mild hypothermia and Tirofiban 5mL/h intravenous pump. Since then, the patient had developed acute profound thrombocytopenia. Conclusion: We reported a case of acute profound thrombocytopenia due to tirofiban treatment during and after interventional therapy. For patients after unilateral nephrectomy, we should pay more attention to avoid the occurrence of thrombocytopenia caused by abnormal metabolism of tirofiban, although the Laboratory examination showed normal results.

17.
ACS Nano ; 17(5): 5033-5046, 2023 03 14.
Article in English | MEDLINE | ID: mdl-36867454

ABSTRACT

Effective drug delivery in the central nervous system (CNS) needs to have long blood-circulation half-lives, to pass through the blood-brain barrier (BBB), and subsequently to be taken up by target cells. Herein, a traceable CNS delivery nanoformulation (RVG-NV-NPs) is developed by encapsulating bexarotene (Bex) and AgAuSe quantum dots (QDs) within Lamp2b-RVG-overexpressed neural stem cell (NSC) membranes. The high-fidelity near-infrared-II imaging by AgAuSe QDs offers a possibility of in vivo monitoring the multiscale delivery process of the nanoformulation from the whole-body to the single-cell scale. It was revealed the synergy of acetylcholine receptor-targeting of RVG and the natural brain-homing and low immunogenicity of NSC membranes prolong the blood circulation, facilitate BBB crossing and nerve cell targeting of RVG-NV-NPs. Thus, in Alzheimer's disease (AD) mice, the intravenous delivery of as low as 0.5% of oral dose Bex showed highly effective up-regulation of the apolipoprotein E expression, resulting rapid alleviation of ∼40% ß-amyloid (Aß) level in the brain interstitial fluid after a single dose administration. The pathological progression of Aß in AD mice is completely suppressed during a 1 month treatment, thus effectively protecting neurons from Aß-induced apoptosis and maintaining the cognitive abilities of AD mice.


Subject(s)
Alzheimer Disease , Mice , Animals , Alzheimer Disease/diagnostic imaging , Alzheimer Disease/drug therapy , Brain/metabolism , Blood-Brain Barrier/metabolism , Amyloid beta-Peptides/metabolism , Cell Membrane/metabolism
18.
Brain Behav ; 13(4): e2932, 2023 04.
Article in English | MEDLINE | ID: mdl-36917737

ABSTRACT

OBJECTIVE: The contribution of large vessel stenosis to the development of white matter hyperintensities (WMHs) has not been fully elucidated. This study aims to explore the correlation between ipsilateral white matter hyperintensities (WMHs) and the severity of large vessel stenosis in the anterior circulation and cerebral perfusion level, as well as analyze the factors influencing WMHs. METHODS: A cross-sectional study of 150 patients with unilateral anterior circulation large vessel stenosis of ≥50% was conducted. The severity of ipsilateral WMHs was assessed by Fazekas scale on T2-weighted image and/or fluid-attenuated inversion recovery MR imaging, vascular stenosis severity was evaluated on computed tomography angiography images, and the level of cerebral perfusion was rated according to a staging system for abnormal cerebral perfusion based on CTP results. The relationships between the stenosis severity, cerebral perfusion level and ipsilateral WMHs severity were analyzed. A multivariate logistic regression analysis was performed to determine the factors independently influencing WMHs. RESULTS: Among 150 patients (mean age, 63.12 ± 10.55 years), there was a statistically significant positive correlation between cerebral perfusion level and the severity of DWMHs and PWMHs (Gamma = 0.561, p < .001; Gamma = 0.600, p < .001), and a positive correlation between cerebral perfusion level and the severity of vascular stenosis (Gamma = 0.495, p < .001).While, there was no statistically significant correlation between the severity of vascular stenosis and the severity of DWMHs and PWMHs (Gamma = 0.188, p = .08; Gamma = 0.196, p = .06). The multivariate logistic regression analysis results demonstrated that age (OR = 1.047, 95% CI 1.003-1.093; p = .035), stroke/TIA history (OR = 2.880, 95% CI 1.154-7.190; p = .023) and stage II of cerebral perfusion (OR = 2.880, 95% CI 1.154-7.190; p = .023) were independent influencing factors on ipsilateral DWMHs. Age (OR = 1.051, 95% CI 1.009-1.094; p = .018), and stage II of cerebral perfusion (OR = 12.871, 95% CI 3.576-46.322; p < .001) were factors independently influencing ipsilateral PWMHs. CONCLUSION: White matter hyperintensities may be attributed to cerebral hypoperfusion secondary to vascular stenosis but not directly to the severity of stenosis in the large vessels of anterior circulation. Moreover, longitudinal studies with sequential imaging exams may further reveal the impact of cerebral perfusion secondary to vascular stenosis on the development and progression of WMHs.


Subject(s)
White Matter , Humans , Middle Aged , Aged , White Matter/diagnostic imaging , Constriction, Pathologic , Cross-Sectional Studies , Magnetic Resonance Imaging/methods , Cerebrovascular Circulation
19.
Molecules ; 28(4)2023 Feb 15.
Article in English | MEDLINE | ID: mdl-36838803

ABSTRACT

High-resolution neutron radiography provides novel and stirring opportunities to investigate the structures of light elements encased by heavy elements. For this study, a series of Gd2O2S:Tb, F particles were prepared using a high-temperature solid phase method and then used as a scintillation screen. Upon reaching 293 nm excitation, a bright green emission originated from the Tb3+ luminescence center. The level of F doping affected the fluorescence intensity. When the F doping level was 8 mol%, the fluorescence intensity was at its highest. The absolute quantum yield of the synthesized particles reached as high as 77.21%. Gd2O2S:Tb, F particles were applied to the scintillation screen, showing a resolution on the neutron radiograph as high as 12 µm. These results suggest that the highly efficient Gd2O2S:Tb, F particles are promising scintillators for the purposes of cold neutron radiography.


Subject(s)
Metals, Rare Earth , Radiography , Gadolinium
20.
Clin Neuroradiol ; 33(2): 537-544, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36536160

ABSTRACT

PURPOSE: This study aimed to identify predictors of rapid improvement of papilledema after stenting and develop a simple preintervention scale. METHODS: A prospective cohort of idiopathic intracranial hypertension (IIH) with venous sinus stenosis (VSS) treated with stenting in a tertiary hospital from January 2014 to December 2019 was reviewed. We categorized papilledema improvement into favorable (grades 0-1) and unfavorable (grades 2-5). We employed logistic regression analysis to find the predictive factors and develop the predictive scale. We then estimated the performance of the scale using the ROC curve and Hosmer-Lemeshow test. RESULTS: There were 110 patients who underwent venous sinus stenting, with a mean age of 37.1 years and a predominance of females (77.3%). A total of 85 patients had a favorable outcome following stenting, while 25 patients had an unfavorable outcome. The results of the multivariate analysis indicate that lower preoperative pressure gradients (odds ratio, OR: 4.01; 95% confidence interval, CI: 1.27-12.68), stenosis rates (OR: 4.16; 95% CI: 1.11-15.56), and preoperative papilledema grades (OR: 2.92; 95% CI: 1.44-5.91) were independently associated with rapid improvement of papilledema following stenting treatment. The 3­item scale exhibited good discrimination with an area under the curve (AOC) of 0.81 (95% CI 0.72-0.89, p < 0.001), as well as acceptable calibration determined by the Hosmer-Lemeshow test (P = 0.42). The optimal cut-off value of the scale (range 0-6 points) was ≥ 4 points, with a sensitivity of 72%, specificity of 73%, and accuracy of 78%. CONCLUSION: The presence of lower preoperative pressure gradients, stenosis severity, and preoperative status of papilledema were identified as positive predictors of rapid improvement of the papilledema following stenting in IIH patients. The 3­item scale provides a promising preintervention predictive model for predicting rapid response following stenting treatment in IIH patients with VSS.


Subject(s)
Papilledema , Pseudotumor Cerebri , Female , Humans , Adult , Male , Pseudotumor Cerebri/complications , Pseudotumor Cerebri/surgery , Papilledema/therapy , Constriction, Pathologic , Prospective Studies , Treatment Outcome , Retrospective Studies , Stents , Cranial Sinuses
SELECTION OF CITATIONS
SEARCH DETAIL
...