Transition metal-free regioselective direct acylation of quinazolines for the synthesis of acylquinazoline derivatives.

An efficient, mild method for direct regioselective acylation of quinazolines under metal-free conditions was developed with bis(trifluoroacetoxy)iodobenzene and trimethylsilyl azide at ambient temperature. The acylation reaction of quinazolines with aldehydes gave the corresponding acyl quinazolines in ethyl acetate with good to excellent yields and excellent functional group tolerance and site selectivity. In addition, the mechanism of the direct acylation of quinazolinone was investigated through HPLC-HRMS (high pressure liquid chromatography-high resolution mass spectrometry) and EPR (electron paramagnetic resonance) strategies.

Thionation toward High-Contrast ACQ-DIE Probes by Reprogramming the Aqueous Segregation Behavior: Enlightenment from a Sulfur-Substituted G-Quadruplex Ligand.

Small-molecule-based fluorescent chemosensors provide powerful tools for analytical chemistry. However, their organic essence often "cursed" them for aggregation-caused quenching (ACQ) in an aqueous context. Albeit the praxis of the disaggregation-induced emission (DIE) strategy as a potential solution, it still awaited improvement due to the uncontrollability of the aggregation/segregation process. To address this issue, herein, we supposed that sulfur substitution on a molecule could serve as a promising strategy to achieve an evolved ACQ-DIE probe. To prove this concept, a precursor G-quadruplex (G4) ligand CQ was modified to get its thionation version CTQ. Strikingly, CTQ exhibited more arranged aqueous segregation behavior, as compared with CQ, and therefore enhanced fluorescence performance. Our research, in the meantime, manifested that CTQ remained to possess favorable G4 selectivity, whereby it could function as an evolved probe for more accurate in vitro G4-related assays, specifically, a classification assay for distinguishing virus variants.

DMF-Assisted Radical Cyclization of o-Isocyanodiaryl Ethers via 1,5-Aryl Migration: Construction of 2-Arylbenzoxazoles.

A novel DMF-assisted radical cyclization of o-isocyanodiaryl ethers via 1,5-aryl migration has been developed for the synthesis of a series of 2-arylbenzoxazoles by the FeCl3/TBHP/Et3N catalytic system in DMF. However, N,N-dimethylbenzo[d]thiazole-2-carboxamide and N,N-dimethylbenzo[d]selenazole-2-carboxamide were obtained from the corresponding substrate 2-isocyanophenyl p-methoxyphenyl thioether and 2-isocyanodiphenyl selenoether under the same conditions. A possible mechanism may involve aryl 1,5-migration and DMF-assisted radical cyclization of o-isocyanodiaryl ethers.

Subtle Structural Changes of Dyes Lead to Distinctly Different Fluorescent Behaviors in Cellular Context: The Role of G-Quadruplex DNA Interaction Using Coumarin-Quinazolinone Conjugates as a Case Study.

Fluorogenic organic materials have gained tremendous attention due to their unique properties. However, only a few of them are suitable for bioimaging. Their different behaviors in organic and cellular environments hinder their application in bioimaging. Thus understanding the photoluminescent behaviors of organic materials in a cellular context is particularly important for their rational design. Herein, we describe two coumarin-quinazolinone conjugates: CQ and MeCQ. The high structure similarity makes them possess similar physical and photophysical properties, including bright fluorescence ascribed to the monomer forms in organic solvents and aggregation-caused quenching (ACQ) effect due to self-assembly aggregation in aqueous solution. However, they behave quite differently in cellular context: that is, CQ exhibits bright fluorescence in living cells, while the fluorescence of MeCQ is almost undetectable. The different performance between CQ and MeCQ in living cells is attributed to their different scenario in G-quadruplex (G4) DNA interaction. CQ selectively binds with G4 DNA to recover its fluorescence via aggregation-disaggregation switching in living cells, while MeCQ remained in the aggregate form due to its poor interplay with G4 DNA. Furthermore, CQ is applied as a two-photon fluorescent dye, and its photoswitchable fluorescence capability is exploited for super-resolution imaging of the specific mitochondrial structure in living cells via the STORM technique.

Rhodium-catalyzed oxidative annulation of 1H-indazoles with alkynes for the synthesis of indazolo[3,2-a]isoquinolines via C-H bond functionalization.

A Rh(iii)-catalyzed oxidative annulation of 1H-indazoles with internal alkynes via C-C and C-N coupling for the preparation of highly functionalized indazolo[3,2-a]isoquinolines is disclosed. This reaction features the use of easily accessible starting materials, is operationally simple, has a relatively wide substrate scope, and shows good functional group tolerance. Furthermore, some of the prepared compounds exhibit bright emission in both dilute solution and in the solid state, with a Stokes shift of up to 161 nm. The derivative 3ia, bearing the strong electron-withdrawing group -NO2, exhibits remarkable solvatochromic fluorescence.

Efficacy and safety of edaravone in treatment of amyotrophic lateral sclerosis-a systematic review and meta-analysis.

BACKGROUND: Based on the results of randomized, double-blind, placebo-controlled trials, the benefit and safety of edaravone in the treatment of amyotrophic lateral sclerosis remain controversial. We performed a meta-analysis to evaluate the efficacy and safety of edaravone in the treatment of this disease. METHODS: We searched PubMed, the Cochrane Library, and Embase from the inception of electronic data to April 2018. We included randomized, double-blind, placebo-controlled trials reporting amyotrophic lateral sclerosis patients receiving 60-mg intravenous edaravone or intravenous saline placebo for 24 weeks. The primary efficacy evaluation was changed in Amyotrophic Lateral Sclerosis Functional Rating Scale score from baseline to after the trial. Measure of safety was the frequency of investigated adverse events and serious adverse events. Data synthesis and analysis and evaluation of risk of bias were performed using RevMan 5.3 software. Heterogeneity among studies was evaluated with the I2 statistic. RESULTS: A total of 367 patients were analyzed across three randomized controlled trials (183 patients receiving intravenous edaravone; 184 receiving placebo). A difference in ALSFRS-R score between groups at 24 weeks was found (mean difference [MD] = 1.63, 95% confidence interval [CI] 0.26-3.00, P = .02). No differences in the frequency of adverse events (odds ratio [OR] = 1.22, 95% CI 0.68-2.19, P = .50) or serious adverse events (OR = 0.71, 95% CI 0.43-1.19, P = .20) were found. CONCLUSION: Intravenous edaravone is efficacious in amyotrophic lateral sclerosis patients, with no severe adverse effects. Additional reliable randomized controlled trials with larger sample sizes will further assess the efficacy and safety of edaravone in amyotrophic lateral sclerosis. CLINICAL TRIAL REGISTRATION: The systematic review and meta-analysis was registered in the international prospective register of systematic reviews. (PROSPERO registration number: CRD42018096191; http://www.crd.york.ac.uk/PROSPERO .).

Asymmetric Difluoroboron Quinazolinone-Pyridine Dyes with Large Stokes Shift: High Emission Efficiencies Both in Solution and in the Solid State.

Boron difluoroquinazolinone-pyridine (BODIQPy) and substituted derivatives have been designed and synthesized. Strong emission with high fluorescence quantum yield both in solution (up to 0.99) and in solid state (up to 0.60) was achieved in these asymmetric BODIQPys. For 6-halogen substituted BODIQPys, the heavy atomic effect of bromine and iodine was suppressed in solution due to the strong electron-withdrawing ability of the BODIQPy core. As a result, 6-iodine substituted BODIQPy shows the unusual fluorescence quantum yields (>0.70) in dichloromethane and tetrahydrofuran. In the solid state, the asymmetric structure induced a unique dimeric structure, and efficient luminescence was also observed. The formation of halogen bonds between carbonyl oxygen and bromine or iodine regulated the stacking mode and enhanced intermolecular interaction, resulting in a decline in the fluorescence quantum yield. In addition, a large Stokes shift was also achieved in these asymmetric BODIQPys.

Preliminary Study on Continuous Recognition of Elbow Flexion/Extension Using sEMG Signals for Bilateral Rehabilitation.

Surface electromyography (sEMG) signals are closely related to the activation of human muscles and the motion of the human body, which can be used to estimate the dynamics of human limbs in the rehabilitation field. They also have the potential to be used in the application of bilateral rehabilitation, where hemiplegic patients can train their affected limbs following the motion of unaffected limbs via some rehabilitation devices. Traditional methods to process the sEMG focused on motion pattern recognition, namely, discrete patterns, which are not satisfactory for use in bilateral rehabilitation. In order to overcome this problem, in this paper, we built a relationship between sEMG signals and human motion in elbow flexion and extension on the sagittal plane. During the conducted experiments, four participants were required to perform elbow flexion and extension on the sagittal plane smoothly with only an inertia sensor in their hands, where forearm dynamics were not considered. In these circumstances, sEMG signals were weak compared to those with heavy loads or high acceleration. The contrastive experimental results show that continuous motion can also be obtained within an acceptable precision range.

Primary Diffuse Large B-Cell Dural Lymphoma With Bone and Subcutaneous Tissue Involvement Mimicking Meningioma.

Primary dural lymphoma (PDL), a rare subtype of primary central nervous system lymphoma (PCNSL), is usually a marginal zone B-cell lymphoma or low-grade B-cell lymphoma of mucosa-associated lymphoid tissue type. Primary dural invasion by diffuse large B-cell lymphoma is extremely rare, with only a few cases reported in the literature. The authors presented an unusual case of primary dural involvement by a high-grade diffuse large B-cell lymphoma that invaded parietal bone and subcutaneous tissue. The patient received tumor complete resection and cranioplasty as well as radiotherapy and chemotherapy as adjuvant treatment after surgery. During 12 months follow-up, no tumor recurrence was found. Primary dural lymphoma should be differentially diagnosed with meningioma. Once the diagnosis of PDL is established, tumor resection and adjuvant radiation and chemotherapy may obtain relatively good prognosis.

Synthesis of Selenium-Containing N-Quinazolinyl Acroleins via a 3,3-Radical Rearrangement Cascade Reaction.

An effective approach for the construction of 2-aryl-3-(3-oxo-1-aryl-2-(organoselanyl)prop-1-en-1-yl)quinazolin-4(3H)-ones was developed. Excellent to almost quantitative yields were obtained by the cascade reaction of propargyl quinazoline-4-yl ethers, diselenides, and 70% tert-butyl hydrogen peroxide aqueous solution under metal-free and mild conditions. The synthesized hybrids, with conglomeration of quinazolinone, organoselenium, aldehyde, and fully substituted alkene moieties in one molecule, will have the potential for applications in development of new drugs or drug candidates.

Bioinformatics analysis of the prognostic role of alternative splicing data in lung adenocarcinoma.

Background: As a post-transcriptional regulatory mechanism, alternative splicing (AS) is engaged in a variety of pathophysiological processes, and it has been widely reported in connection with the occurrence, progression, metastasis, and drug resistance of cancer. However, the research on AS in lung adenocarcinoma (LUAD) is very limited. In addition, the prognostic effect of AS event (ASE) on LUAD and its related mechanism are not clear. This study aimed to explore the role and potential prognostic value of ASE in LUAD. Methods: Relevant data and ASE datasets of the sample were acquired from The Cancer Genome Atlas (TCGA) and TCGASpliceSeq databases. We constructed a new prognostic criterion based on ASEs. Then, Cox regression and least absolute shrinkage and selection operator (LASSO) regression analysis were used to construct the model. Based on this model, the risk score of each ASE was calculated, and the reliability of this model was evaluated by Kaplan-Meier survival and receiver operating characteristic (ROC) curve analyses. Finally, these results were verified on different network platforms. Results: We identified seven types of ASEs related to survival. The prognostic risk model for ASEs was established. The Kaplan-Meier curve showed that compared to the low-risk group, the overall survival (OS) rate of LUAD patients in the high-risk group was lower. ROC curve analysis showed that the prognostic risk model of LUAD patients was well predicted, and the area under the curve (AUC) also confirmed this. Conclusions: This study screened the ASE related to the prognosis of LUAD patients, and provided a theoretical basis for further study of the correlation between ASE and the prognosis of LUAD patients. It has provided new ideas for developing new biomarkers and therapeutic targets for LUAD patients.

Endoplasmic Reticulum-Targeting Quinazolinone-Based Lipophilic Probe for Specific Photoinduced Ferroptosis and Its Induced Lipid Dynamic Regulation.

Lethal lipid peroxidation caused by reactive oxygen species occurs in different types of programmed cell death, especially in ferroptosis. Ferroptosis inducers, which serve as small-molecule probes, can provide insight into the mechanism of ferroptosis and facilitate drug discovery. The classical ferroptosis inducers indirectly lead to lipid peroxidation; thus, it is difficult to explore lipid regulation during the ferroptotic process. In this study, we designed two quinazolinone-based lipophilic probes BODIQPy-TPA and QPy-TPA, which proved to directly induce lipid peroxidation by light irradiation in vitro. The probe BODIQPy-TPA, which was mainly distributed in the endoplasmic reticulum (ER), specifically triggered ferroptosis in B16 and HepG2 cells upon light irradiation. As a comparison, the probe QPy-TPA, which was mainly distributed in lipid droplets (LDs), induced cell death by a nonferroptotic pathway. Further lipidomic analysis revealed that these two probes caused different patterns of lipid regulation and lipid peroxidation, suggesting that ferroptosis might activate distinct lipid regulation.

Implementation of human-machine synchronization control for active rehabilitation using an inertia sensor.

According to neuro-rehabilitation practice, active training is effective for mild stroke patients, which means these patients are able to recovery effective when they perform the training to overcome certain resistance by themselves. Therefore, for rehabilitation devices without backdrivability, implementation of human-machine synchronization is important and a precondition to perform active training. In this paper, a method to implement this precondition is proposed and applied in a user's performance of elbow flexions and extensions when he wore an upper limb exoskeleton rehabilitation device (ULERD), which is portable, wearable and non-backdrivable. In this method, an inertia sensor is adapted to detect the motion of the user's forearm. In order to get a smooth value of the velocity of the user's forearm, an adaptive weighted average filtering is applied. On the other hand, to obtain accurate tracking performance, a double close-loop control is proposed to realize real-time and stable tracking. Experiments have been conducted to prove that these methods are effective and feasible for active rehabilitation.

A novel soft biomimetic microrobot with two motion attitudes.

 A variety of microrobots have commonly been used in the fields of biomedical engineering and underwater operations during the last few years. Thanks to their compact structure, low driving power, and simple control systems, microrobots can complete a variety of underwater tasks, even in limited spaces. To accomplish our objectives, we previously designed several bio-inspired underwater microrobots with compact structure, flexibility, and multi-functionality, using ionic polymer metal composite (IPMC) actuators. To implement high-position precision for IPMC legs, in the present research, we proposed an electromechanical model of an IPMC actuator and analysed the deformation and actuating force of an equivalent IPMC cantilever beam, which could be used to design biomimetic legs, fingers, or fins for an underwater microrobot. We then evaluated the tip displacement of an IPMC actuator experimentally. The experimental deflections fit the theoretical values very well when the driving frequency was larger than 1 Hz. To realise the necessary multi-functionality for adapting to complex underwater environments, we introduced a walking biomimetic microrobot with two kinds of motion attitudes: a lying state and a standing state. The microrobot uses eleven IPMC actuators to move and two shape memory alloy (SMA) actuators to change its motion attitude. In the lying state, the microrobot implements stick-insect-inspired walking/rotating motion, fish-like swimming motion, horizontal grasping motion, and floating motion. In the standing state, it implements inchworm-inspired crawling motion in two horizontal directions and grasping motion in the vertical direction. We constructed a prototype of this biomimetic microrobot and evaluated its walking, rotating, and floating speeds experimentally. The experimental results indicated that the robot could attain a maximum walking speed of 3.6 mm/s, a maximum rotational speed of 9°/s, and a maximum floating speed of 7.14 mm/s. Obstacle-avoidance and swimming experiments were also carried out to demonstrate its multi-functionality.

Polymicrobial Anaerobic Meningitis Detected by Next-Generation Sequencing: Case Report and Review of the Literature.

Background: Anaerobic meningitis is a severe central nervous system infection associated with significant neurological sequelae and high mortality. However, the precise detection of causative pathogen(s) remains difficult because anaerobic bacteria are difficult to culture. Next-generation sequencing is a technology that was developed recently and has been applied in many fields. To the best of our knowledge, the use of next-generation sequencing for cerebrospinal fluid analysis in the diagnosis of anaerobic meningitis has been rarely reported. Case presentation: Here, we report a case of polymicrobial anaerobic meningitis diagnosed using next-generation sequencing of cerebrospinal fluid in a 16-year-old girl. Five species of anaerobic bacteria (Porphyromonas gingivalis, Prevotella enoeca, Campylobacter rectus, Fusobacterium uncleatum, and Actinomyces israelii) were detected by next-generation sequencing and treated with antibacterial agents (ceftriaxone, vancomycin, and metronidazole). The patient responded well to antibacterial treatment. Further inspection revealed bone destruction at the base of the skull, which further confirmed that these bacteria had originated from the oral cavity. One month later, the patient's condition improved significantly. At the same time, we performed a literature review on anaerobic meningitis using studies published in the last 20 years. Conclusions: This case emphasizes the importance of applying metagenomic next-generation sequencing to clinch the clinical diagnosis for patients with central nervous system infection. Metagenomic next-generation sequencing has been reported to be an important diagnostic modality for identifying uncommon pathogens.

A Novel Biomimetic Compliant Structural Skin Based on Composite Materials for Biorobotics Applications.

Biorobotics is increasingly attracting engineers worldwide, due to the high impact this field can have on the society. Biorobotics aims at imitating or taking inspiration from mechanisms and strategies evolved by animals, including their locomotion abilities in real scenarios, such as swimming, running, crawling, and flying. However, the development of skin-mimicking structures, allowing protection without hindering artifacts' movements, has been rarely addressed. Skin-mimicking structures play a key role for biomimetic robots that have to move in unstructured environments. Currently most of the skin used for robots in engineering adopts soft materials or bellow structures to enable both structural deformation and protection. However, the elastic nature of the former can produce support failure and increasing strain with deformation, while the humpy surface of the latter reduces the interactive performance with the environment. Herein, we designed a novel compliant structure for biorobots' skin, fabricated through a special configuration of both soft and rigid materials to reproduce attributes provided by natural epithelial structures. The presented skin has a simple fabrication process, as well as it is cost effective. The structure of this skin includes a thin conical shape where rigid iron rings are wrapped by soft polyester fabrics, allowing a theoretically zero elastic modulus when bended and stretched. The dimension of fabrics was specified to allow rigid rings having a certain range of free rotation and translation. The possibility of free bending and stretching of the structure was implemented by overcoming low sliding friction of adjacent rings. To empirically test the effectiveness of the proposed structure, a model, including 20 segments, was also fabricated. Experimental results from the bending tests, both in aerial and underwater environments, as well as from the folding tests, demonstrated the successful performance of the skin prototype in terms of low resistance and energy consumption. Finally, the proposed highly compliant structural skin was mounted and tested on a fish robot previously developed by authors, to further show its effectiveness.

A Trajectory Tracking Control Based on a Terminal Sliding Mode for a Compliant Robot with Nonlinear Stiffness Joints.

A nonlinear stiffness actuator (NSA) can achieve high torque/force resolution in the low stiffness range and high bandwidth in the high stiffness range. However, for the NSA, due to the imperfect performance of the elastic mechanical component such as friction, hysteresis, and unmeasurable energy consumption caused by former factors, it is more difficult to achieve accurate position control compared to the rigid actuator. Moreover, for a compliant robot with multiple degree of freedoms (DOFs) driven by NSAs, the influence of every NSA on the trajectory of the end effector is different and even coupled. Therefore, it is a challenge to implement precise trajectory control on a robot driven by such NSAs. In this paper, a control algorithm based on the Terminal Sliding Mode (TSM) approach is proposed to control the end effector trajectory of the compliant robot with multiple DOFs driven by NSAs. This control algorithm reduces the coupling of the driving torque, and mitigates the influence of parametric variation. The closed-loop system's finite time convergence and stability are mathematically established via the Lyapunov stability theory. Moreover, under the same experimental conditions, by the comparison between the Proportion Differentiation (PD) controller and the controller using TSM method, the algorithm's efficacy is experimentally verified on the developed compliant robot. The results show that the trajectory tracking is more accurate for the controller using the TSM method compared to the PD controller.

Highly selective suppression of melanoma cells by inducible DNA cross-linking agents: bis(catechol) derivatives.

A series of bis(catechol) quaternary ammonium derivatives were designed and synthesized. We investigated their ability to cross-link DNA induced by tyrosinase and found that the o-quinone is key intermediate in the process by using the nucleophile 3-methyl-2-benzothiazolinone hydrazone (MBTH) in the tyrosinase assay. Their cytotoxicities to B16F1, Hela, and CHO cells were tested by MTT assays. The specific and potent abilities to kill the tyrosinase-efficient melanoma cells kindled our interest in exploring the relationship between their abilities of cross-linking DNA and their selective cytotoxicities to cells. Through an integrated approach including intracellular imaging for detection of the dihydroxyphenyl groups, alkaline comet assays, and γ-H2AX immunofluorescence assays, the speculation was confirmed. The bis(catechol) quaternary ammonium derivatives showed notable cell selectivity because they displayed cytotoxicities after being oxidized by tyrosinase, and they were able to target the DNA efficiently in the tyrosinase-efficient melanoma cells, forming both alkylated and cross-linked species.

Prediction of Passive Torque on Human Shoulder Joint Based on BPANN.

In upper limb rehabilitation training by exploiting robotic devices, the qualitative or quantitative assessment of human active effort is conducive to altering the robot control parameters to offer the patients appropriate assistance, which is considered an effective rehabilitation strategy termed as assist-as-needed. Since active effort of a patient is changeable for the conscious or unconscious behavior, it is considered to be more feasible to determine the distributions of the passive resistance of the patient's joints versus the joint angle in advance, which can be adopted to assess the active behavior of patients combined with the measurement of robotic sensors. However, the overintensive measurements can impose a burden on patients. Accordingly, a prediction method of shoulder joint passive torque based on a Backpropagation neural network (BPANN) was proposed in the present study to expand the passive torque distribution of the shoulder joint of a patient with less measurement data. The experiments recruiting three adult male subjects were conducted, and the results revealed that the BPANN exhibits high prediction accurate for each direction shoulder passive torque. The results revealed that the BPANN can learn the nonlinear relationship between the passive torque and the position of the shoulder joint and can make an accurate prediction without the need to build a force distribution function in advance, making it possible to draw up an assist-as-needed strategy with high accuracy while reducing the measurement burden of patients and physiotherapists.

Efficacy and safety of sonothrombolysis in patients with acute ischemic stroke: A systematic review and meta-analysis.

BACKGROUND: Accumulating clinical evidence has indicated that sonothrombolysis can aid in the treatment of ischemic stroke; however, these findings remain controversial. The purpose of the present meta-analysis was to assess randomized clinical studies concerning the effects of sonothrombolysis on ischemic stroke to evaluate its safety and efficacy. METHODS: We systematically searched the Cochrane Library, PubMed, and EMBASE databases for literature published between the inception of electronic data and May 2019 regarding sonothrombolysis for acute ischemic stroke. Only randomized controlled trials were included. Data extraction was based on patient characteristics, ultrasound variables (any duration or frequency, without microbubble), and outcome variables (safety and efficacy). RESULTS: Five trials were included in the present study. Clinical functional recovery was evaluated at different time points (several days or 3 months), and heterogeneity was low. Sonothrombolysis did not lead to an increase in symptomatic intracranial hemorrhagic complications or death. Our results demonstrated that patients treated with sonothrombolysis had significantly higher rates of recanalization and asymptomatic intracerebral hemorrhage than patients treated with intravenous thrombolysis alone. In the subgroup of middle cerebral artery (MCA) occlusion patients, sonothrombolysis was found to greatly increase the efficacy outcomes compared to intravenous thrombolysis. CONCLUSIONS: Evidence suggests that sonothrombolysis is a technically feasible and potentially effective treatment that has beneficial effects on recanalization and increases the rate of asymptomatic intracerebral hemorrhage in stroke patients. Additionally, short- and long-term clinical outcome analyses were improved in the MCA occlusion sonothrombolysis subgroup. Larger clinical trials of MCA occlusion patients are necessary to verify these findings.