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1.
J Colloid Interface Sci ; 667: 291-302, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38640649

RESUMO

Single atom metal-nitrogen-carbon materials have emerged as remarkably potent catalysts, demonstrating unprecedented potential for the photo-driven reduction of CO2. Herein, a unique Cu@g-C3N5 catalyst obtained by cooperation of single atom Cu and nitrogen-rich g-C3N5 is proposed. The particular CuN diatomic active sites (DAS) in Cu@g-C3N5 contribute to the formation of highly stable CuOCN adsorption, a key configuration for CO2 activation and CC coupling. The synergistic diatomic active sites interaction is found responsible for the efficient photoreduction of CO2 to C2H4 which has been demonstrated in our Gibbs free energy calculation and COHP analysis. The CO2 activation mechanism was studied, the charge density difference and DOS analysis show that the low oxidation state Cu atom significantly affects the electronic structure of g-C3N5 and then enhance the catalytic activity of CO2 hydrogenation.

2.
Phys Chem Chem Phys ; 26(9): 7731-7737, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38372286

RESUMO

Successful conversion of CO2 into C2 products requires the development of new catalysts that overcome the difficulties in efficient light harvesting and CO-CO coupling. Herein, density functional theory (DFT) is used to assess the photoreduction properties of nitrogen-doped black phosphorus. The geometric structure, redox potential, first step of hydrogenation activation, CO desorption, and CO-CO coupling are systematically calculated, based on which the diatomic nitrogen-doped black phosphorus (N2@BPV) stands out. The calculated results of the CO2RR pathway demonstrate that N2@BPV has excellent selectivity and high activity for CH3CH2OH production. The results of the time-dependent ab initio nonadiabatic molecular dynamics simulation show that the diatomic N active sites of N2@BPV facilitate charge separation and inhibit electron-hole recombination. In addition, the activation mechanism of CO2 is studied. The main reason for CO2 activation is attributed to the imbalance in electron transfer that destroys the symmetry of CO2. We expect that our study will offer some theoretical guidance in CO2 conversion.

3.
Polymers (Basel) ; 15(20)2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37896414

RESUMO

Vat photopolymerization-based additive manufacturing (AM) is critical in improving solutions for wearable sensors. The ability to add nanoparticles to increase the polymer resin's mechanical, electrical, and chemical properties creates a strong proposition for investigating custom nanocomposites for the medical field. This work uses a low-cost biocompatible polymer resin enhanced with multi-walled carbon nanotubes (MWCNTs), and a digital light processing-based AM system to develop accurate strain sensors. These sensors demonstrate the ability to carry a 244% maximum strain while lasting hundreds of cycles without degradation at lower strain ranges. In addition, the printing process allows for detailed prints to be accomplished at a sub-30 micron spatial resolution while also assisting alignment of the MWCNTs in the printing plane. Moreover, high-magnification imagery demonstrates uniform MWCNT dispersion by utilizing planetary shear mixing and identifying MWCNT pullout at fracture locations. Finally, the proposed nanocomposite is used to print customized and wearable strain sensors for finger motion monitoring and can detect different amounts of flexion and extension. The 3D printed nanocomposite sensors demonstrate characteristics that make it a strong candidate for the applications of human kinematics monitoring and sensing.

4.
Neurosurg Rev ; 46(1): 234, 2023 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-37682426

RESUMO

Dual-lumen angioplasty balloon microcatheters make it possible to perform percutaneous transluminal angioplasty (PTA), low-profile stent delivery, and intrastent dilation without the microcatheter exchange technique. This technique has shown many advantages in recent years. We reviewed the techniques and applications in different intracranial vascular diseases and summarized the outcomes and indications. Gateway dual-lumen angioplasty balloon was used for PTA and kept in situ. Stent was delivered and deployed via Gateway microcatheter. Intrastent balloon dilation was performed after stent deployment. We retrospectively reviewed the clinical and imaging data, surgical procedures, technique application, and follow-up outcomes of six patients treated from 2020 to 2023. Neurological function was assessed by the modified Rankin scale (mRS). A literature review was performed using PubMed. All seven patients (4 males, 3 females; mean age, 62.6 ± 6.9 years) underwent percutaneous transluminal angioplasty and stent deployment using a balloon microcatheter. There was one middle cerebral artery (MCA) aneurysm with parent artery stenosis, two MCA dissections, and four intracranial atherosclerotic stenoses (ICASs). The mRS score was 0 in five patients and 1 in two patients. Cerebral dissection with stenosis is the best indication, and its application in stent-assisted aneurysm coiling is inappropriate. This technique is controversial in ICAS treatment.


Assuntos
Angioplastia , Dissecação , Feminino , Masculino , Humanos , Pessoa de Meia-Idade , Idoso , Dilatação , Constrição Patológica , Estudos Retrospectivos
5.
J Chem Inf Model ; 63(15): 4708-4715, 2023 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-37537716

RESUMO

The charge transfer mechanism of the g-C3N4/MoS2 heterojunction is still disputed. Some regard it as a type I pathway, some regard it as a type II pathway, and still some regard it as a Z-scheme pathway. Especially, the results obtained by density functional theory (DFT) calculations are not totally in agreement. Here, we constructed four g-C3N4/MoS2 heterojunctions on the basis of the aperture alignment modes of g-C3N4 and MoS2. Their morphology and photocatalytic activity were investigated via first-principles and excited state dynamics simulations. By systemically comparing the interfacial binding energy and electronic structure (e.g., band structure, electrostatic potential, and band edge positions) of g-C3N4/MoS2 heterojunctions, we found that both type I and type II band alignment structures could be obtained. Moreover, the calculated lifetimes of interlayer photogenerated electrons and holes show that type II g-C3N4/MoS2 tends to favor a general type II pathway rather than a Z-scheme pathway. This study could provide a deep understanding of the photocatalytic mechanism of g-C3N4/MoS2 van der Waals heterostructures, which will be of great use for applications in photocatalysis.

6.
Front Neurol ; 14: 1200539, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37576021

RESUMO

Persistent hypoglossal artery (PHA) is a rare carotid-vertebrobasilar anastomosis in adults. Here, we report a case of mechanical thrombectomy for acute basilar artery occlusion via the PHA. A 44-year-old man was admitted to our stroke unit with an unstable gait and aphasia for 2 h. The baseline National Institutes of Health Stroke Scale (NIHSS) score was 4, but the clinical symptoms continued to worsen. Computed tomography angiography showed the absence of the basilar artery and an abnormal anastomosis between the anterior and posterior circulation. Clinical symptoms continued to worsen, and endovascular treatment was scheduled. PHA was demonstrated and basilar artery occlusion was confirmed using digital subtraction angiography. Mechanical thrombectomy with a stent retriever and aspiration was performed via the PHA, and modified thrombolysis in cerebral infarction level 3 was achieved. The patient underwent intravenous antiplatelet therapy after the operation, and follow-up neuroimaging revealed multiple small infarcts in the cerebellum and medulla oblongata. The patient was discharged after 10 days for further rehabilitation, with an NIHSS score of 25. At 10 months follow-up, the NIHSS score decreased to 18. Recognition of this rare variation is particularly important for interventional strategy determination and rapid recanalization of basilar artery occlusion.

7.
Phys Chem Chem Phys ; 25(32): 21554-21561, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37545410

RESUMO

The rational construction of photocatalysts possesses tremendous potential to solve the energy crisis and environmental pollution; however, designing a catalyst for solar-driven overall water-splitting remains a great challenge. Herein, we propose a new MoS2-based photocatalyst (Co-P@MoS2), which skillfully uses the cobalt (Co) atom to stimulate in-plane S atoms and employs the phosphorus (P) atom to stabilize the basal plane by forming the Co-P bands. Using density functional theory (DFT), it was found that oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) can occur at the P site and S2 site of the Co-P@MoS2, respectively, and the dual-active sites successfully makes a delicate balance between the adsorption and dissociation of hydrogen. Furthermore, the improved overall water-splitting performance of Co-P@MoS2 was verified by analyzing the results of the electron structure and the dynamics of photogenerated carries. It was found that the imbalance of electron transfer caused by the introduction of the Co atom was the main contributor to the catalytic activity of Co-P@MoS2. Our study broadens the idea of developing photocatalysts for the overall water-splitting.

8.
Elife ; 122023 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-37551094

RESUMO

The ability to adjust the speed of locomotion is essential for survival. In limbed animals, the frequency of locomotion is modulated primarily by changing the duration of the stance phase. The underlying neural mechanisms of this selective modulation remain an open question. Here, we report a neural circuit controlling a similarly selective adjustment of locomotion frequency in Drosophila larvae. Drosophila larvae crawl using peristaltic waves of muscle contractions. We find that larvae adjust the frequency of locomotion mostly by varying the time between consecutive contraction waves, reminiscent of limbed locomotion. A specific set of muscles, the lateral transverse (LT) muscles, co-contract in all segments during this phase, the duration of which sets the duration of the interwave phase. We identify two types of GABAergic interneurons in the LT neural network, premotor neuron A26f and its presynaptic partner A31c, which exhibit segmentally synchronized activity and control locomotor frequency by setting the amplitude and duration of LT muscle contractions. Altogether, our results reveal an inhibitory central circuit that sets the frequency of locomotion by controlling the duration of the period in between peristaltic waves. Further analysis of the descending inputs onto this circuit will help understand the higher control of this selective modulation.


Assuntos
Drosophila , Neurônios Motores , Animais , Drosophila/fisiologia , Larva/fisiologia , Neurônios Motores/fisiologia , Contração Muscular , Locomoção/fisiologia
9.
Clin Neurol Neurosurg ; 231: 107818, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37356200

RESUMO

OBJECTIVE: Complex anterior cerebral artery (ACA) aneurysms are still technically challenging to treat. Bypass surgery is needed to achieve aneurysm obliteration and ACA territory revascularization. Severe atherosclerosis of aneurysm walls can cause clip slippage, intraoperative rupture, postoperative ischemic events. How to assess the atherosclerotic changes in vascular walls by high-resolution vessel wall magnitude resonance imaging (VWI) is the key question in complex ACA aneurysm surgical management. METHODS: This retrospective single-center study included eight patients diagnosed with complex anterior cerebral arteries admitted to our hospital for bypass surgery from January 2019 to April 2022. We discussed the application of VWI in aneurysms treated with in situ bypass and reviewed previous experience of revascularization strategies for complex ACA aneurysms. RESULTS: In this study, we treated 8 cases of complex ACA aneurysms (3 communicating aneurysms/5 postcommunicating aneurysms) over the prior one year. In situ side-to-side anastomosis (1 A2-to-A2/6 A3-to-A3) was performed in seven cases, and trapping combined with excision was performed in another case. Following bypass, complete trapping was performed in 4 cases, and proximal clipping was performed in 3 cases. No surgery-related neurological dysfunctions were observed. The final modified Rankin scale was 0 in seven of the eight cases and 2 in one case. CONCLUSION: High-resolution VWI, as a favorable preoperative assessment tool, provides insight into patient-specific anatomy and microsurgical options before operations, which can help neurosurgeons develop individualized and valuable surgical plans.


Assuntos
Revascularização Cerebral , Aneurisma Intracraniano , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/cirurgia , Revascularização Cerebral/métodos , Estudos Retrospectivos , Artéria Cerebral Anterior/diagnóstico por imagem , Artéria Cerebral Anterior/cirurgia , Procedimentos Neurocirúrgicos/métodos
10.
Bioengineering (Basel) ; 10(5)2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37237608

RESUMO

Cochlear implant (CI) surgery is one of the most utilized treatments for severe hearing loss. However, the effects of a successful scala tympani insertion on the mechanics of hearing are not yet fully understood. This paper presents a finite element (FE) model of the chinchilla inner ear for studying the interrelationship between the mechanical function and the insertion angle of a CI electrode. This FE model includes a three-chambered cochlea and full vestibular system, accomplished using µ-MRI and µ-CT scanning technologies. This model's first application found minimal loss of residual hearing due to insertion angle after CI surgery, and this indicates that it is a reliable and helpful tool for future applications in CI design, surgical planning, and stimuli setup.

11.
J Med Chem ; 66(8): 5439-5452, 2023 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-37029334

RESUMO

Cyclin-dependent kinase 8 (CDK8), as a kinase subunit of the Mediator complex, is involved in the regulation of RNA polymerase II-mediated transcription, thereby modulating multiple signaling pathways and multiple transcription factors involved in oncogenic control. CDK8 deregulation has been implicated in human diseases, particularly in acute myeloid leukemia (AML) and advanced solid tumors, where it has been reported as a putative oncogene. Here, we report the successful optimization of an azaindole series of CDK8 inhibitors that were identified and further progressed through a structure-based generative chemistry approach. In several optimization cycles, we improved in vitro microsomal stability, kinase selectivity, and in vivo pharmacokinetic profile cross-species, leading to the discovery of compound 23, which demonstrated robust tumor growth inhibition in multiple in vivo efficacy models after oral administration.


Assuntos
Quinase 8 Dependente de Ciclina , Neoplasias , Humanos , Neoplasias/genética , Complexo Mediador/metabolismo , Oncogenes , Inibidores de Proteínas Quinases/farmacologia
12.
Artigo em Inglês | MEDLINE | ID: mdl-36912907

RESUMO

Highly flexible, deformable, and ultralightweight structures are required for advanced sensing applications, such as wearable electronics and soft robotics. This study demonstrates the three-dimensional (3D) printing of highly flexible, ultralightweight, and conductive polymer nanocomposites (CPNCs) with dual-scale porosity and piezoresistive sensing functions. Macroscale pores are established by designing structural printing patterns with adjustable infill densities, while the microscale pores are developed by phase separation of the deposited polymer ink solution. A conductive polydimethylsiloxane solution is prepared by mixing polymer/carbon nanotubes with non-solvent and solvent phases. Silica nanoparticles are utilized to modify the rheological properties of the ink, making direct ink writing (DIW) feasible. 3D geometries with various structural infill densities and polymer concentrations are deposited using DIW. The solvent is evaporated during a stepping heat treatment, leading to non-solvent droplet nucleation and growth. The microscale cellular network is developed by removing the droplets and curing the polymer. Up to 83% tunable porosity is achieved by independently controlling the macro- and microscale porosity. The effect of macroscale/microscale porosity and printing nozzle sizes on the mechanical and piezoresistive behavior of the CPNC structures is explored. The electrical and mechanical tests demonstrate a durable, extremely deformable, and sensitive piezoresistive response without sacrificing mechanical performance. The flexibility and sensitivity of the CPNC structure are enhanced up to 900 and 67% with the development of dual-scale porosity. The application of the developed porous CPNCs as piezoresistive sensors for detecting human motion is also evaluated.

13.
Chem Sci ; 14(6): 1443-1452, 2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36794205

RESUMO

The application of artificial intelligence (AI) has been considered a revolutionary change in drug discovery and development. In 2020, the AlphaFold computer program predicted protein structures for the whole human genome, which has been considered a remarkable breakthrough in both AI applications and structural biology. Despite the varying confidence levels, these predicted structures could still significantly contribute to structure-based drug design of novel targets, especially the ones with no or limited structural information. In this work, we successfully applied AlphaFold to our end-to-end AI-powered drug discovery engines, including a biocomputational platform PandaOmics and a generative chemistry platform Chemistry42. A novel hit molecule against a novel target without an experimental structure was identified, starting from target selection towards hit identification, in a cost- and time-efficient manner. PandaOmics provided the protein of interest for the treatment of hepatocellular carcinoma (HCC) and Chemistry42 generated the molecules based on the structure predicted by AlphaFold, and the selected molecules were synthesized and tested in biological assays. Through this approach, we identified a small molecule hit compound for cyclin-dependent kinase 20 (CDK20) with a binding constant Kd value of 9.2 ± 0.5 µM (n = 3) within 30 days from target selection and after only synthesizing 7 compounds. Based on the available data, a second round of AI-powered compound generation was conducted and through this, a more potent hit molecule, ISM042-2-048, was discovered with an average Kd value of 566.7 ± 256.2 nM (n = 3). Compound ISM042-2-048 also showed good CDK20 inhibitory activity with an IC50 value of 33.4 ± 22.6 nM (n = 3). In addition, ISM042-2-048 demonstrated selective anti-proliferation activity in an HCC cell line with CDK20 overexpression, Huh7, with an IC50 of 208.7 ± 3.3 nM, compared to a counter screen cell line HEK293 (IC50 = 1706.7 ± 670.0 nM). This work is the first demonstration of applying AlphaFold to the hit identification process in drug discovery.

14.
Oper Neurosurg (Hagerstown) ; 24(5): 322-329, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36716013

RESUMO

BACKGROUND: The bypass technique is important for treating complex intracranial aneurysms and is infrequently performed. Intracranial-intracranial (IC-IC) bypass has shown many advantages in recent years. OBJECTIVE: To review the techniques and outcomes of bypass based on anterior cerebral artery (ACA) A1 donor anastomosis in patients with intracranial aneurysm. METHODS: We retrospectively reviewed the clinical and imaging data, surgical strategy, and follow-up outcomes of 7 patients treated from 2019 to 2022. Neurological function was assessed by the modified Rankin Scale (mRS). A literature review was performed using PubMed. RESULTS: All 7 patients (3 male patients and 4 female patients; mean age, 50.4 ± 15.5 years) underwent aneurysm trapping or clipping using interposition IC-IC bypass based on ACA-A1 donor anastomosis. There were 6 middle cerebral artery (MCA) aneurysms and 1 posterior cerebral aneurysm in the series. One IC-IC bypass failed and was changed to extracranial-intracranial bypass. Three patients with MCA M1 aneurysm showed perforator-related infarction after the operation. The modified Rankin Scale score was 0 in 4 patients, 2 in 2 patients, and 1 in 1 patient. The long-term graft patency rate was 100%. CONCLUSION: Interposition IC-IC bypass based on ACA-A1 donor anastomosis provides an effective way to achieve blood flow reconstruction in the treatment of complex aneurysms. This technique provides better caliber and volume compatibility and diminishes neck incision. Perforator-related infarction was the main complication because of involvement of the MCA M1 aneurysm location. Proximal clipping is preferred to avoid perforator-related infarction.


Assuntos
Revascularização Cerebral , Aneurisma Intracraniano , Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Artéria Cerebral Anterior/diagnóstico por imagem , Artéria Cerebral Anterior/cirurgia , Revascularização Cerebral/métodos , Estudos Retrospectivos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/cirurgia , Anastomose Cirúrgica
15.
Chin Neurosurg J ; 8(1): 41, 2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36517912

RESUMO

BACKGROUND: Dural arteriovenous fistulas (DAVF) represent almost 10-15% of intracranial malformations that cause intracranial hemorrhage and focal neurological deficits. Seldom tentorial DAVF cases present with ocular manifestations initially, which occur frequently in carotid-cavernous fistula (CCF) and cavernous sinus DAVF (CS DAVF). CASE PRESENTATION: We report an unusual falcotentorial DAVF case draining via the superior and inferior ophthalmic veins that caused left-side increased intraocular pressure. The patient's chief complaint was swelling on the left side, pain and conjunctival congestion. He received endovascular embolization via a transarterial approach, and postoperative angiography demonstrated that the falcotentorial DAVF was occluded completely. CONCLUSION: Except for CCF and CS DAVF, some specific subtypes of DAVF should be considered if the patient initially presents with ocular symptoms. Differential diagnosis and definitive treatment are mandatory to avoid a delayed diagnosis and irreversible symptoms.

16.
Front Neurol ; 13: 945961, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35959410

RESUMO

Background: Scalp arteriovenous malformations (AVM) are rare vascular malformations reported only in small case series. Scalp AVMs usually present with symptoms, including headache, tinnitus, epilepsy, cerebral ischemia, and necrosis of the scalp, which can cause functional, cosmetic, and psychological problems. There are many difficulties in the treatment of scalp AVM because of its complex characteristics of vascular anatomy, non-uniform structure, and intracranial-extracranial anastomosis. Case description: To illustrate the endovascular treatment of scalp AVM via direct percutaneous puncture while traditional arterial and venous approaches were not available. In this report, access was obtained through a direct puncture of the enlarged frontal vein. Onyx-18 was injected through a microcatheter to occlude draining veins, fistulous connection, and the feeders. An 18-gauge indwelling needle was inserted into draining veins directly. Postembolization angiography demonstrated complete sAVM occlusion immediately and no non-targeted embolization. At a 1-year follow-up, no procedure-related complications and evidence of recurrence were observed. Conclusion: The technique of endovascular embolization via direct percutaneous puncture approach is safe, rapid, and effective for specific sAVM. Treatment options should be made in terms of size, vascular anatomical characteristics of the lesions, patient's preference, cosmetic factors, and available expertise.

17.
World Neurosurg ; 166: e770-e780, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35933096

RESUMO

BACKGROUND: A cavernous sinus (CS) dural arteriovenous fistula (DAVF) is a form of abnormal arteriovenous communication that can be treated with endovascular embolization. Establishing an optimal access route should be based on vascular architecture. We reviewed 64 patients with CS-DAVF who underwent endovascular embolization and report the endovascular treatment approach selection and outcome. METHODS: Clinical data were obtained from 64 patients with CS-DAVF who had been surgically treated at the authors' hospital between 2009 and 2022. Patients' medical records, imaging data, and follow-up outcomes were retrospectively analyzed. RESULTS: All 64 patients (15 male, 49 female; mean age, 50 years) underwent CS-DAVF embolization. The most common symptoms were exophthalmos (39.1%), chemosis (35.9%), and headache (28.1%). On digital subtraction angiography images, 34.4% of the DAVFs were unilateral, and 82.8% were fed by both the external carotid artery and internal carotid artery. Of the patients' inferior petrosal sinuses (IPSs), 54.7% were nonopacified. The most common intravascular approaches included trans-IPS (37.5%) and trans-artery (28.1%) approaches. More than half of the CS-DAVFs were embolized by both coils and Onyx (62.5%). A total of 85.9% of the fistulas were completely embolized, and the follow-up rate was 76.6%. The modified Rankin Scale score was 0.9 ± 1.0. CONCLUSIONS: The vascular architecture of CS-DAVF is closely related to endovascular treatment approach selection and outcome. Combined with the modified IPS recanalization technique, the trans-IPS approach is the safest and most effective approach. Dual microcatheter and balloon assistance techniques ensure the safety and completeness of embolization.


Assuntos
Seio Cavernoso , Malformações Vasculares do Sistema Nervoso Central , Embolização Terapêutica , Procedimentos Endovasculares , Exoftalmia , Artéria Carótida Interna , Seio Cavernoso/diagnóstico por imagem , Seio Cavernoso/cirurgia , Malformações Vasculares do Sistema Nervoso Central/diagnóstico por imagem , Malformações Vasculares do Sistema Nervoso Central/cirurgia , Embolização Terapêutica/métodos , Procedimentos Endovasculares/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
18.
Polymers (Basel) ; 14(13)2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35808573

RESUMO

Devices for the endovascular embolization of intracranial aneurysms (ICAs) face limitations related to suboptimal rates of lasting complete occlusion. Incomplete occlusion frequently leads to residual flow within the aneurysm sac, which subsequently causes aneurysm recurrence needing surgical re-operation. An emerging method for improving the rates of complete occlusion both immediately after implant and in the longer run can be the fabrication of patient-specific materials for ICA embolization. Shape memory polymers (SMPs) are materials with great potential for this application, owing to their versatile and tunable shape memory properties that can be tailored to a patient's aneurysm geometry and flow condition. In this review, we first present the state-of-the-art endovascular devices and their limitations in providing long-term complete occlusion. Then, we present methods for the fabrication of SMPs, the most prominent actuation methods for their shape recovery, and the potential of SMPs as endovascular devices for ICA embolization. Although SMPs are a promising alternative for the patient-specific treatment of ICAs, there are still limitations that need to be addressed for their application as an effective coil-free endovascular therapy.

19.
BMC Biol ; 20(1): 130, 2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35701821

RESUMO

BACKGROUND: Animal locomotion requires dynamic interactions between neural circuits, the body (typically muscles), and surrounding environments. While the neural circuitry of movement has been intensively studied, how these outputs are integrated with body mechanics (neuromechanics) is less clear, in part due to the lack of understanding of the biomechanical properties of animal bodies. Here, we propose an integrated neuromechanical model of movement based on physical measurements by taking Drosophila larvae as a model of soft-bodied animals. RESULTS: We first characterized the kinematics of forward crawling in Drosophila larvae at a segmental and whole-body level. We then characterized the biomechanical parameters of fly larvae, namely the contraction forces generated by neural activity, and passive elastic and viscosity of the larval body using a stress-relaxation test. We established a mathematical neuromechanical model based on the physical measurements described above, obtaining seven kinematic values characterizing crawling locomotion. By optimizing the parameters in the neural circuit, our neuromechanical model succeeded in quantitatively reproducing the kinematics of larval locomotion that were obtained experimentally. This model could reproduce the observation of optogenetic studies reported previously. The model predicted that peristaltic locomotion could be exhibited in a low-friction condition. Analysis of floating larvae provided results consistent with this prediction. Furthermore, the model predicted a significant contribution of intersegmental connections in the central nervous system, which contrasts with a previous study. This hypothesis allowed us to make a testable prediction for the variability in intersegmental connection in sister species of the genus Drosophila. CONCLUSIONS: We generated a neurochemical model based on physical measurement to provide a new foundation to study locomotion in soft-bodied animals and soft robot engineering.


Assuntos
Drosophila , Locomoção , Animais , Fenômenos Biomecânicos , Drosophila/fisiologia , Larva/fisiologia , Locomoção/fisiologia , Músculos
20.
Am J Transl Res ; 14(5): 2861-2873, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35702105

RESUMO

OBJECTIVE: To investigate the role of lncRNA SNHG6 (SNHG6) in gastric carcinoma (GC) and its relationship with the PI3K/AKT/mTOR signaling pathway in order to provide more comprehensive and reliable reference for the diagnosis and treatment of GC. METHODS: GC patients admitted to our hospital from May 2017 to August 2018 as well as healthy individuals who underwent physical examinations during the same time period were enrolled in this study. The serum SNHG6 level was quantified. Patients were followed up for 3 years to analyze the significance of SNHG6 in the diagnosis and treatment of GC. Finally, in vitro assays were performed to determine the influences of SNHG6 and PI3K/AKT/mTOR signaling pathway on biological behaviors and autophagy ability of GC cells. RESULTS: SNHG6 showed high expression in patients with GC and its expression decreased after therapy. SNHG6 also demonstrated a favorable predictive value for the development of GC and the death of patients. The survival curve suggested that increased SNHG6 indicated a higher risk of death. Additionally, mRNA of PI3K/AKT/mTOR pathway related molecules was highly expressed in GC patients. In in vitro assays, GC cells showed stronger viability and invasion activity and weaker apoptosis and autophagy ability after targeted up-regulation of SNHG6. According to the rescue assay, the effect of up-regulating SNHG6 on GC cells could be completely reversed by suppressing the PI3K/AKT/mTOR pathway. CONCLUSION: With high expression in patients with GC, SNHG6 can promote the development of GC by activating the PI3K/AKT/mTOR signaling pathway and suppressing the autophagy of cells. Therefore, it is a potential breakthrough in the diagnosis and treatment of GC in the future.

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