Design, Synthesis, and Performance of Photo-Responsive Liquid Crystal Polymers with Stepwise Deformation Capability.

Photo-responsive liquid crystal polymers (LCPs) have potential application value in flexible robots, artificial muscles, and microfluidic control. In recent years, significant progress has been made in the development of LCPs. However, the preparation of LCPs with continuous and controllable stepwise deformation capabilities remains a challenge. In this study, visible photo-responsive cyanostilbene monomer, UV photo-responsive azobenzene monomer, and multiple hydrogen bond crosslinker are used to prepare photo-responsive LCPs capable of achieving continuously and controllable stepwise deformation. The comprehensive investigation of the multiple light response ability and photo-induced deformation properties of these copolymers is conducted. The results reveal that in the first stage of photo-induced deformation under 470 nm blue light irradiation, the deformation angle decreases with a reduction in cyanostilbene content in the copolymer component, ranging from 40° in AZ0-CS4 to 0° in AZ4-CS0. In the second stage of photo-induced deformation under 365 nm UV irradiation, the deformation angle increases with the increase of azobenzene content, ranging from 0° of AZ0-CS4 to 89.4° of AZ4-CS0. Importantly, the deformation between these two stages occurs as a continuous process, allowing for a direct transition from the first-stage to the second-stage deformation by switching the light source from 470 to 365 nm.

Clustering-Triggered Emission Liquid Crystalline Polymer Bearing Cholesterol: Tunable Circularly Polarized Luminescence and Room-Temperature Phosphorescence.

Circularly polarized luminescence (CPL) materials with clustering-triggered emission (CTE) characteristic have gradually attracted attention for their unique photophysical properties. However, the majority of reported clusteroluminogens lack chirality and exhibit heterogeneity, making it challenging to achieve a well-defined helical structure necessary for efficient CPL with high dissymmetry factor (glum ). In this paper, chiral liquid crystals are constructed to obtain CTE-based CPL materials with high glum values. Side chain liquid crystal polymer PM6Chol bearing cholesterol clusteroluminogens are designed and synthesized. PM6Chol-coated film and PM6Chol thermal-treated film are also successfully prepared by different film-forming methods. Both the films inherit the CTE characteristic of cholesterol and show excitation wavelength-dependent luminescent behavior. However, the two polymer films exhibit different liquid crystal phase structures, with PM6Chol-coated film being a chiral bilayer smectic C phase and PM6Chol thermal-treated film being an achiral bilayer smectic A phase. Attributed to helical arrangement of cholesterol, PM6Chol-coated film emits efficient CPL with glum values up to 1.0 × 10-1 . For PM6Chol thermal-treated film, no CPL signal is detected due to the absence of helical structure. However, it shows obvious room-temperature phosphorescence with 2.0 s afterglow and 23.9 ms lifetime.

The preparation and properties of circularly polarized luminescent liquid crystal physical gels with self-supporting performance.

In recent years, great progress has been made in the preparation methods and performance regulation of host-guest doped CPL liquid crystal materials. However, there still exist some basic problems to be solved, such as complex packaging and unstable CPL properties. With the consideration of the above problems, in this study, we introduced gelators into the host-guest doped CPL liquid crystal materials to prepare CPL liquid crystal physical gels. The gelators can be assembled to form a nanofiber physical gel network, which limits the movement of the liquid crystals and enhances the stability of the CPL properties. Meanwhile, liquid crystal physical gels show self-supporting ability and the gel-sol phase transition temperature can reach 136 °C. The amplification of the glum value is achieved by self-assembly of chiral liquid crystals, and the glum value can reach -0.31. The phase structure changes with electric field and temperature, and the CPL properties can be regulated by changing the temperature and electric field. With the increasing applied voltage or the temperature, the glum value decreases. Therefore, we have successfully prepared a new type of CPL liquid crystal physical gels with self-supporting performance, stimulus response performance and large glum values.

Manipulated and Improved Photoinduced Deformation Property of Photoresponsive Liquid Crystal Elastomers by Copolymerization.

Photoresponsive liquid crystal elastomers (LCEs) have aroused much attention due to their unique structures, properties, and potential applications. However, many reported photoresponsive LCEs show small photoinduced deformation with a slow deformation speed, which limits their application to a certain extent. In this article, multiple hydrogen bond component and biphenyl component was introduced into photoresponsive LCEs bearing cyanostilbene by copolymerization, and prepared a series of LCEs CSm-BPn (CS and BP means cyanostilbene and biphenyl component, respectively; m, n means the content ratio of CS and BP). All uniaxially oriented CSm-BPn fibers show photoinduced deformation behavior under 365 nm UV light except for CS0-BP5. The introduction of hydrogen bond and the decrease of glass transition temperature realize large deformation and fast deformation speed. Besides, the properties of LCEs are successfully regulated by changing the content ratio of each component. What's more interesting is that the addition of appropriate amount of biphenyl can significantly improve and manipulate the deformation property of the CSm-BPn fibers. The maximum bending angle can reach 175° , and the whole photoinduced deformation process only takes 11 s. The photoresponsive LCEs with such large bending angle and fast deformation rate are rarely reported.

Current Status of the Application of Intracranial Venous Sinus Stenting.

The intracranial venous sinus is an important component of vascular disease. Many diseases involve the venous sinus and are accompanied by venous sinus stenosis (VSS), which leads to increased venous pressure and high intracranial pressure. Recent research has focused on stenting as a treatment for VSS related to these diseases. However, a systematic understanding of venous sinus stenting (VS-Stenting) is lacking. Herein, the literature on idiopathic intracranial hypertension (IIH), venous pulsatile tinnitus, sinus thrombosis, high draining venous pressure in dural arteriovenous fistula (AVF) and arteriovenous malformation (AVM), and tumor-caused VSS was reviewed and analyzed to summarize experiences with VS-Stenting as a treatment. The literature review showed that satisfactory therapeutic effects can be achieved through stent angioplasty. Thus, the present study suggests that selective stent release in the venous sinus can effectively treat these diseases and provide new possibilities for treating intracranial vascular disease.

Pituitary adenoma apoplexy caused by rupture of an anterior communicating artery aneurysm: case report and literature review.

BACKGROUND: Pituitary adenoma combined with intracranial aneurysm is not rare. Some aneurysms are located inside pituitary adenomas, and most do not rupture. Pituitary apoplexy caused by aneurysm rupture is rare and is easily misdiagnosed as simple pituitary adenoma apoplexy. CASE PRESENTATION: In this study, we report one case of rare pituitary adenoma apoplexy caused by the rupture of an anterior communicating artery aneurysm. The patient was a 49-year-old male who had an untreated pituitary adenoma for 3 years. The patient experienced a sudden headache; computed tomography (CT) and magnetic resonance imaging (MRI) revealed pituitary adenoma apoplexy and significant subarachnoid hemorrhage. Cranial CT angiography (CTA) showed a communicating artery aneurysm. Supratentorial intracranial aneurysm clipping and pituitary adenoma resection were performed. The aneurysm was a ruptured aneurysm located inside the pituitary adenoma. During the surgery, the aneurysm was clipped, and the majority of the tumor was resected. The patient recovered well after the surgery and received radiotherapy. CONCLUSIONS: This rare case demonstrates that when pituitary adenoma apoplexy is combined with subarachnoid hemorrhage, the possibility of a combined intrasellar aneurysm should be considered. During transsphenoidal tumor resection, aneurysm rupture should be avoided to prevent disastrous consequences.

Application of the chick embryo chorioallantoic membrane in neurosurgery disease.

The chick embryo chorioallantoic membrane (CAM) is a highly vascularized extraembryonic membrane. Because of its ease of accessibility, extensive vascularization and immunodeficient environment, the CAM has been broadly used in the oncology, biology, pharmacy, and tissue regeneration research. The present review summarizes the application of the CAM in neurosurgery disease research. We focused on the use of the CAM as an assay for the research of glioma, vascular anomalies, Moyamoya Disease, and the blood-brain barrier.

Research progress on vertebrobasilar dolichoectasia.

Vertebrobasilar dolichoectasia (VBD) is a rare disease characterized by significant expansion, elongation, and tortuosity of the vertebrobasilar arteries. Current data regarding VBD are very limited. Here we systematically review VBD incidence, etiology, characteristics, clinical manifestations, treatment strategies, and prognosis. The exact incidence rate of VBD remains unclear, but is estimated to be 1.3% of the population. The occurrence of VBD is thought to be due to the cooperation of multiple factors, including congenital factors, infections and immune status, and degenerative diseases. The VBD clinical manifestations are complex with ischemic stroke as the most common, followed by progressive compression of cranial nerves and the brain stem, cerebral hemorrhage, and hydrocephalus. Treatment of VBD remains difficult. Currently, there are no precise and effective treatments, and available treatments mainly target the complications of VBD. With the development of stent technology, however, it may become an effective treatment for VBD.

Biocompatible PEGylated Fe3O4 nanoparticles as photothermal agents for near-infrared light modulated cancer therapy.

In accordance with the World Cancer Report, cancer has become the leading cause of mortality worldwide, and various therapeutic strategies have been developed at the same time. In the present study, biocompatible magnetic nanoparticles were designed and synthesized as high-performance photothermal agents for near-infrared light mediated cancer therapy in vitro. Via a facile one-pot solvothermal method, well-defined PEGylated magnetic nanoparticles (PEG-Fe3O4) were prepared with cheap inhesion as a first step. Due to the successful coating of PEG molecules on the surface of PEG-Fe3O4, these nanoparticles exhibited excellent dispersibility and dissolvability in physiological condition. Cytotoxicity based on MTT assays indicated these nanoparticles revealed high biocompatibility and low toxicity towards both Hela cells and C6 cells. After near-infrared (NIR) laser irradiation, the viabilities of C6 cells were effectively suppressed when incubated with the NIR laser activated PEG-Fe3O4. In addition, detailed photothermal anti-cancer efficacy was evaluated via visual microscope images, demonstrating that our PEG-Fe3O4 were promising for photothermal therapy of cancer cells.

General Strategy to Prepare Nondoped Circularly Polarized Luminescent Liquid Crystal Materials with Tunable Performance.

Chiral luminescent liquid crystals have attracted widespread attention from researchers due to their unique advantages in constructing circularly polarized luminescent (CPL) materials with large luminescent asymmetry factor (glum) values. However, how to effectively prepare nondoped CPL chiral liquid crystals remains a challenge. In this article, we developed an effective and universal method to prepare nondoped CPL chiral liquid crystal materials. To achieve our strategy, we copolymerized chiral monomer M0Mt with α-cyanostilbene-based luminescent monomers MmPVPCN (m = 6, 8, 10) bearing different flexible spacer lengths to obtain a series of CPL chiral liquid crystal copolymers poly(MmPVPCN(x)-co-M0Mt(y)). Under the induction of the chiral component, the α-cyanostilbene component assembles to form chiral liquid crystals. Meanwhile, α-cyanostilbene also exhibits aggregation-induced emission enhancement characteristics. Therefore, with the help of the selective reflection effect of chiral liquid crystals, the copolymer films can emit efficient CPL. For poly(M8PVPCN(0.85)-co-M0Mt(0.15)), the glum and solid luminescence quantum yield can achieve -2.61 × 10-2 and 25.04%, respectively. In addition, by altering the chemical structure of the copolymers, the phase structure of the copolymers can be effectively controlled, thereby regulating their CPL properties.

Synthesis and Properties of Room-Temperature Phosphorescent Liquid Crystal Copolymers with Linearly Polarized Luminescence Characteristic.

Room-temperature phosphorescent (RTP) liquid crystal materials have garnered considerable attention because of their significant applications in organic light emitting diodes, polarized light emitting materials, and so forth. How to efficiently synthesize pure organic RTP liquid crystals and regulate their performance is of great significance. In this article, we propose a simple and feasible method to synthesize RTP liquid crystals and manipulate their properties through copolymerization. We constructed RTP liquid crystal copolymers by copolymerizing a phosphorescent monomer bearing biphenyl mesogen with a phosphorescent monomer bearing a dibenzofuran chromophore. All the synthesized copolymers show a liquid crystal property because of the introduction of biphenyl mesogen. Meanwhile, by changing the composition of copolymers, it is possible to regulate their RTP performance, including luminescence color and lifetime. As the content of the PMDFM0C component in copolymers increases, the phosphorescence lifetime gradually increases. For poly(MDFM0C(0.46)-co-MBi18C(0.54)), the phosphorescence lifetime can reach 463.0 ms. Moreover, the phosphorescence color of the PMDFM0C component in copolymers changes with the copolymer composition, which can induce variable room-temperature phosphorescence. In addition, when oriented, liquid crystal copolymer films can emit linearly polarized fluorescence and linearly polarized phosphorescence. The linearly polarized phosphorescence dichroic ratio and polarization ratio values of the oriented poly(MDFM0C(0.46)-co-MBi18C(0.54)) film are 3.33 and 0.50, respectively.

Safety and efficacy analysis of the off-label use of pipeline embolization devices for intracranial aneurysms: a propensity score matching study.

Background and objective: The safety and efficacy of on-label use of pipeline embolization devices (PEDs) are well established; however, there is much controversy over their off-label use. This study aimed to investigate the safety and efficacy of the off-label use of PEDs for treating intracranial aneurysms. Methods: This single-center study retrospectively included patients with digital subtraction angiography, computed tomographic angiography, or magnetic resonance angiography confirmed intracranial aneurysms treated with PEDs who were admitted to our institution between 1 January 2018 and 1 July 2022. Patients were divided into on- and off-label groups according to the Food and Drug Administration criteria published in 2021. Propensity score matching (PSM) was used to balance disparities in baseline information between the two groups. Safety outcomes included postoperative mortality and complication rates, whereas effectiveness outcomes included aneurysm occlusion rate (O'Kelly-Marotta grading system C + D grades), retreatment rate within 12 months, and postoperative functional score [modified Rankin scale (mRS) score]. The study was approved by the Ethics Committee of Scientific Research and Clinical Trial of the First Affiliated Hospital of Zhengzhou University (Ethics number: KY 2018-098-02). All patients provided informed consent. Results: A total of 242 patients with 261 aneurysms (160 on-label and 101 off-label aneurysms) were included in this study. PSM yielded 81 pairs of patients matched for baseline information. Postoperative hemorrhagic, ischemic, and procedure-related complication rates did not reach statistical significance. In addition, no statistically significant differences in the aneurysm occlusion rate, retreatment rate within 12 months, postoperative functional score (mRS score), or mRS score deterioration rate were observed between the two groups. A higher incidence of in-stent stenosis was observed in the off-label (4.9% vs. 21%, p = 0.002) group than in the on-label group; however, all patients were asymptomatic. Conclusion: Compared with on-label use, off-label use of PEDs for treating intracranial aneurysms did not increase the risk of complications, and the occlusion rates were comparable. Therefore, decisions regarding clinical management should not rely solely on on- or off-label indications.

6-Gingerol via overexpression of miR-322-5p impede lipopolysaccharide-caused inflammatory response in RAW264.7 cells.

Acute lung injury (ALI) and sepsis are complicated syndromes that are often left untreated in critically ill patients. 6-Gingerol is a phenolic phytochemical compound that is found in fresh ginger, has pharmacological effects against inflammation. This study explored the roles of 6-gingerol in a mouse model of acute lung injury caused by lipopolysaccharide (LPS) and RAW-264.7 cells inflammation. The LPS-induced animal model underwent histopathological examinations, and RAW-264.7 cells viability was determined by Cell counting Kit-8 (CCk-8) assay. Additionally, qRT-PCR, Immunofluorescence, Western blot, and ELISA were used in vivo and in vitro to identify inflammatory factors and proteins associated with NF-κB and MAPK signaling pathways. In a histological examination 6-gingerol exhibited protective effects. Moreover, 6-gingerol elevated cell viability and downregulated inflammatory factors Interlukin-1ß (IL-1ß), Interlukin-6 (IL-6) and Tumor necrosis factor-α (TNF-α) in LPS-treated RAW-264.7 cells. Furthermore, 6-gingerol decreased phosphorylation of P65, P38 and the level of JNK in NF-κB and MAPK pathways. Importantly, 6-gingerol increased transcript abundance of miR-322-5p which suppressed by LPS and miR-322-5p downregulation negated the protective functions of 6-gingerol. The protective activity of 6-gingerol was mediated by miR-322-5p up-regulation.

Evaluation of the apposition in unruptured aneurysms treated with flow diverters by optical coherence tomography: Preliminary clinical experience.

Background: The risk of perioperative stroke and the rate of occlusion of long-term aneurysms in the treatment of unruptured aneurysms with flow diverters (FDs) are affected by stent apposition. Optical coherence tomography (OCT) may be an optional technique in evaluating apposition. Purpose: To explore the feasibility of the OCT imaging technique in evaluating stent apposition in the clinical application of the FD for unruptured aneurysms. Methods: OCT and Vaso CT were used in patients with indications for surgery to treat unruptured aneurysms with the FDs, to evaluate the apposition of the FDs after fully released, and to analyze OCT images for FDs apposition and compare with corresponding Vaso CT images. Results: A total of four patients were enrolled, and OCT found malapposition after FDs placement in all four patients, and the maximum gap between the stent and vascular wall ranged from 0.68 to 1.95 mm and the length of malapposition ranged from 1.80 to 7.40 mm. However, Vaso CT found malapposition only in two of the four patients and missed malapposition near aneurysm in all three patients treated by the FD combined with coiling and could not accurately evaluate the maximum gap and the length of the malapposition. Conclusion: The optical coherence tomography technique is a possible approach to evaluate apposition after the treatment of unruptured aneurysms by the FDs.

Devastating iatrogenic internal carotid artery rupture in endoscopic endonasal surgery rescued by a covered stent.

Iatrogenic ICA injury is a life-threatening and underreported complication of EES. For selected patients, covered stent implantation is the best and only way to block the rupture spot immediately and maintain ICA blood flow.

Oxidative Stress Activated by Sorafenib Alters the Temozolomide Sensitivity of Human Glioma Cells Through Autophagy and JAK2/STAT3-AIF Axis.

The development of temozolomide (TMZ) resistance in glioma leads to poor patient prognosis. Sorafenib, a novel diaryl urea compound and multikinase inhibitor, has the ability to effectively cross the blood-brain barrier. However, the effect of sorafenib on glioma cells and the molecular mechanism underlying the ability of sorafenib to enhance the antitumor effects of TMZ remain elusive. Here, we found that sorafenib could enhance the cytotoxic effects of TMZ in glioma cells in vitro and in vivo. Mechanistically, the combination of sorafenib and TMZ induced mitochondrial depolarization and apoptosis inducing factor (AIF) translocation from mitochondria to nuclei, and this process was dependent on STAT3 inhibition. Moreover, the combination of sorafenib and TMZ inhibited JAK2/STAT3 phosphorylation and STAT3 translocation to mitochondria. Inhibition of STAT3 activation promoted the autophagy-associated apoptosis induced by the combination of sorafenib and TMZ. Furthermore, the combined sorafenib and TMZ treatment induced oxidative stress while reactive oxygen species (ROS) clearance reversed the treatment-induced inhibition of JAK2/STAT3. The results indicate that sorafenib enhanced the temozolomide sensitivity of human glioma cells by inducing oxidative stress-mediated autophagy and JAK2/STAT3-AIF axis.

Tandem stents thrombectomy as a rescue treatment for refractory large vessel occlusions.

BACKGROUND: Mechanical thrombectomy with a stent retriever (SR) and/or aspiration is the 'gold standard' for the treatment of acute ischemic stroke due to large vessel occlusion (LVO). However, sometimes clots may not be retrievable with a single SR alone or combined with aspiration. OBJECTIVE: To assess the safety and efficacy of a novel tandem stents thrombectomy (TST) technique as a rescue treatment for acute LVO that is refractory to conventional attempts. METHODS: All patients treated with the TST technique as rescue treatment after failure of conventional attempts were retrospectively reviewed. The postprocedural angiographic and clinical outcome, including modified Thrombolysis in Cerebral infarction (mTICI) grade, National Institutes of Health Stroke Scale (NIHSS) score, and modified Rankin Scale (mRS) score, was assessed. RESULTS: Nine patients (mean age, 65.2 years; median NIHSS score 18) with middle cerebral artery M1 segment (n=6) and terminal internal carotid artery (n=3) occlusions were included in the study. The TST technique was performed as a rescue treatment after unsuccessful stent thrombectomy alone (four cases) and stent thrombectomy plus aspiration (five cases). Successful recanalization (mTICI 2b/3) was achieved in all patients. No procedure-related complications occurred except reversible vasospasms were observed in three patients and one patient developed hemorrhage transformation after the procedure, but was asymptomatic. Three patients had good clinical outcome (mRS score 0-2 at 90 days). Two patients (22.2%) died. CONCLUSIONS: The TST technique seems to be a safe and effective rescue treatment for acute LVO that is refractory to conventional attempts.

Mechanical Thrombectomy with Stent Retriever 29 Days After Onset of Ischemic Stroke.

A patient presented with progressive ischemic stroke and received mechanical thrombectomy with a Solitaire FR device 29 days after stroke onset. The occluded V4 segment of the left vertebral artery showed a double rail sign on angiography, which indicated that the occlusion might have been caused by embolism instead of stenosis. The mechanical thrombectomy procedure was a 1-pass success and the patient was functionally independent with a modified Rankin Scale score of 1 at 3-month follow-up. The appearance of the vascular wall (double rail sign) of the occluded cerebral vascular segment on angiography may be a significant feature to identify the character of the occlusion even a long time after onset, which is important when planning further endovascular therapy in patients with ischemic stroke.

Dual Stimuli-Responsive High-Efficiency Circularly Polarized Luminescence from Light-Emitting Chiral Nematic Liquid Crystals.

Considerable luminescence dissymmetry factor (glum) is vital for application implementation of circularly polarized luminescence (CPL) materials. Moreover, a dual CPL switch has promising prospects in high-security encryption and sensor devices. Herein, we designed and synthesized an emissive chiral nematic liquid crystal (N*-LC) by doping a luminescent chiral additive (NO2-CS-C6-Chol) into a nematic liquid crystal (5CB). The helical assembly structure produced by inducing the formation of N*-LC endows the prepared emissive N*-LC with a larger glum value. With the increase of the doping concentration from 1 to 10 wt %, the helical pitch (P) of N*-LC gradually decreases from 25.48 to 3.92 µm. The corresponding glum value increases first, reaches the maximum value (-0.38) at 6 wt %, and then decreases slightly. Further, the prepared emissive N*-LC doped with 6 wt % NO2-CS-C6-Chol is injected into an indium-tin oxide (ITO)-coated LC cell, to which a direct current (DC) electric field is applied. The glum value can be repeatedly shuttled between the "on" and "off" state by adjusting the applied voltage. Meanwhile, owing to the inherent thermal dependence of the liquid crystal phase structure, the glum value can also be switched between the on and off state by regulating the temperature. Therefore, an electrically controlled and thermocontrolled dual CPL switching device is successfully constructed.

Advances of spontaneous emulsification and its important applications in enhanced oil recovery process.

Emulsions, including oil-in-water (O/W) and water-in-oil (W/O) emulsions, can play important roles in both controlling reservoir conformance and displacing residual oil for enhanced oil recovery (EOR) projects. However, current methods, like high-shear mixing, high-pressure homogenizing, sonicators and others, often use lots of extra energy to prepare the emulsions with high costs but very low energy efficiency. In recent decades, spontaneous emulsification methods, which allow one to create micro- and nano-droplets with very low or even no mechanical energy input, have been launched as an overall less expensive and more efficient alternatives to current high extra energy methods. Herein, we primarily review the basic concepts on spontaneous emulsification, including mechanisms, methods and influenced parameters, which are relevant for fundamental applications for industrials. The spontaneity of the emulsification process is influenced by the following variables: surfactant structure, concentration and initial location, oil phase composition, addition of co-surfactant and non-aqueous solvent, as well as salinity and temperature. Then, we focus on the description of importance for emulsions in EOR processes from advances and categories to improving oil recovery mechanisms, including both sweep efficiency and displacement efficiency aspects. Finally, we systematically address the applications and outlooks based on the use of spontaneous emulsification in the practical oil reservoirs for EOR processes, in which conventional, heavy, high-temperature, high-salinity and low-permeability oil reservoirs, as well as wastewater treatments after EOR processes are involved.