Bioinformatics analysis of ferroptosis in spinal cord injury.

Ferroptosis plays a key role in aggravating the progression of spinal cord injury (SCI), but the specific mechanism remains unknown. In this study, we constructed a rat model of T10 SCI using a modified Allen method. We identified 48, 44, and 27 ferroptosis genes that were differentially expressed at 1, 3, and 7 days after SCI induction. Compared with the sham group and other SCI subgroups, the subgroup at 1 day after SCI showed increased expression of the ferroptosis marker acyl-CoA synthetase long-chain family member 4 and the oxidative stress marker malondialdehyde in the injured spinal cord while glutathione in the injured spinal cord was lower. These findings with our bioinformatics results suggested that 1 day after SCI was the important period of ferroptosis progression. Bioinformatics analysis identified the following top ten hub ferroptosis genes in the subgroup at 1 day after SCI: STAT3, JUN, TLR4, ATF3, HMOX1, MAPK1, MAPK9, PTGS2, VEGFA, and RELA. Real-time polymerase chain reaction on rat spinal cord tissue confirmed that STAT3, JUN, TLR4, ATF3, HMOX1, PTGS2, and RELA mRNA levels were up-regulated and VEGFA, MAPK1 and MAPK9 mRNA levels were down-regulated. Ten potential compounds were predicted using the DSigDB database as potential drugs or molecules targeting ferroptosis to repair SCI. We also constructed a ferroptosis-related mRNA-miRNA-lncRNA network in SCI that included 66 lncRNAs, 10 miRNAs, and 12 genes. Our results help further the understanding of the mechanism underlying ferroptosis in SCI.

Antioxidant, AChE inhibitory, and anticancer effects of Verbascum thapsus extract.

Verbascum thapsus (VT) is a medicinal plant that is used in folk medicine to treat a variety of ailments. For this study, the biological functions of VT methanol extract were determined in vitro. The plant's methanol extract was created through the maceration process. The phytochemical composition of plant extracts was investigated using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The antioxidant capacity of the extract was determined using the DPPH (2,2-diphenyl-1-picrylhydrazil) and ABTS (2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) tests and its cytotoxicity was assessed using the MTT ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, a tetrazole)) assay on the Caco-2 (human colorectal adenocarcinoma cells), LNCaP (Lymph Node Carcinoma of the Prostate), and HEK293 cell lines (Human embryonic kidney 293 cells) used to model colon, prostate, and non-cancerous cells. VT extract showed low DPPH and ABTS radical scavenging activities compared to standard antioxidants at 30 mg/ml concentration. In addition, it was determined that VT extract inhibited acetylcholinesterase enzyme.

Synergistic Nanowire-Enhanced Electroporation and Electrochlorination for Highly Efficient Water Disinfection.

Conventional water disinfection methods such as chlorination typically involve the generation of harmful disinfection byproducts and intensive chemical consumption. Emerging electroporation disinfection techniques using nanowire-enhanced local electric fields inactivate microbes by damaging their outer structures without byproduct formation or chemical dosing. However, this physical-based method suffers from a limited inactivation efficiency under high water flux due to an insufficient contact time. Herein, we integrate electrochlorination with nanowire-enhanced electroporation to achieve a synergistic flow-through process for efficient water disinfection targeting bacteria and viruses. Electroporation at the cathode induces sub-lethal damages on the microbial outer structures. Subsequently, electrogenerated active chlorine at the anode aggravates these electroporation-induced injuries to the level of lethal damage. This sequential flow-through disinfection system achieves complete disinfection (>6.0-log) under a very high water flux of 2.4 × 104 L/(m2 h) with an applied voltage of 2.0 V. This disinfection efficiency is 8 times faster than that of electroporation alone. Further, the specific energy consumption for the disinfection by this novel process is extremely low (8 × 10-4 kW h/m3). Our results demonstrate a promising method for rapid and energy-efficient water disinfection by coupling electroporation with electrochlorination to meet vital needs for pathogen elimination.

Recent progress and challenges in solution blow spinning.

In the past 30 years, researchers have worked towards reducing the size of ordinary three-dimensional (3D) materials into 1D or 2D materials in order to obtain new properties and applications of these low-dimensional systems. Among them, functional nanofibers with large surface area and high porosity have been widely studied and paid attention to. Because of the interesting properties of nanofibers, they find extensive application in filtration, wound dressings, composites, sensors, capacitors, nanogenerators, etc. Recently, a variety of nanofiber preparation methods such as melt blowing, electrospinning (e-spinning), centrifugal spinning and solution blow spinning (SBS) have been proposed. This paper includes a brief review of the fundamental principles of the preparation of nanofibers for solution jet spinning, the influence of experimental parameters, and the properties and potential applications of the solution-blown fibers. And the industrialization and challenges of SBS are also included.

High output achieved by sliding electrification of an electrospun nano-grating.

The rapid development of flexible and wearable electronics has proposed a trend towards miniaturization, mobility, versatility and artificial intelligence. Triboelectric nanogenerators (TENGs) can make use of micro/nano multi-functional materials to harvest and store energy from the surrounding environment efficiently, which can drive smart portable electronics operating continuously and steadily. The increase in the output power density of the triboelectric nanogenerator requires new designs. In this work, a new grating TENG was proposed, and the two friction layers were fabricated by near-field electrospinning and conventional electrospinning with two parallel electrodes as a collector, respectively. The basic model of the simulation was simplified according to the highly ordered structure and the repeatability of the TENG grating structure. The effect of the effective contact area on the output of the TENG was further proved by fitting the calculation regularity of the two models with the experimental results. At the same time, the effect of the redundant electrode on the output of the TENG was verified by experiments. We found that this nanogenerator can achieve a very high output of 1800 W m-2 due to a more refined grating structure combined with modification of the contact area. The TENG can also be used as a selfpowered sensor to detect mechanical signals, which requires no additional power source to drive it. Meanwhile, the anisotropic nature of the TENG can also be utilized to sense angles, lock devices or encrypt information. This output control technology provides a more effective idea for future output power improvement, that is, a new generation of high-output TENGs can be designed by effectively adjusting the corresponding contact area and electrode area.

A novel diagnostic method for distinguishing between Fe(IV) and •OH by using atrazine as a probe: Clarifying the nature of reactive intermediates formed by nitrilotriacetic acid assisted Fenton-like reaction.

In this work, we found that the distribution of two specific atrazine (ATZ) oxidation products (desethyl-atrazine (DEA) and desisopropyl-atrazine (DIA)) was different in oxidation processes involving aqueous ferryl ion (Fe(IV)) species and •OH. Specifically, the molar ratio of produced DEA to DIA (i.e., [DEA]/[DIA]) increased from 7.5 to 13 with increasing pH from 3 to 6 when ATZ was oxidized by Fe(IV), while the treatment of ATZ by •OH led to the [DEA]/[DIA] value of 2 which was independent of pH. Moreover, ATZ showed high reactivity towards Fe(IV) over a wide pH range, especially at near-neutral pH, at which ATZ oxidation in Fe(II)/peroxydisulfate system was even much faster than another well-defined Fe(IV) scavenger, the sulfoxides. By using this approach, it was obtained that the [DEA]/[DIA] value remained at 2 during ATZ transformation by the nitrilotriacetic acid (NTA) assisted Fenton-like (Fe(III)/H2O2) system, which was independent of solution pH and reactants dosage. This result clarified that •OH was the primary reactive intermediate formed in the NTA assisted Fe(III)/H2O2 system. This study not only developed a novel sensitive diagnostic tool for distinguishing Fe(IV) from •OH, but also provided more credible evidence to the nature of reactive intermediate in a commonly controversial system.

Enhancement of Cr(VI) removal efficiency via adsorption/photocatalysis synergy using electrospun chitosan/g-C3N4/TiO2 nanofibers.

Chitosan/g-C3N4/TiO2 (CS/CNT) nanofibers were fabricated by electrospinning technique for Cr(VI) removal through the adsorption and photocatalytic processes. The effects of crucial factors in the adsorption process including contact time (0-1440 min), pH (1-7), initial concentration of Cr(VI) (20-800 mg/L) were investigated. The photocatalytic experiment was executed in a photochemical reactor with an 800 W xenon lamp to simulate visible light. In adsorption process, at pH = 2, the adsorption capacities of chitosan (CS) nanofibers, CS/CNT10:1 (CS : g-C3N4/TiO2 = 10:1) nanofibers and CS/CNT5:1 nanofibers were 20.8, 165.3 and 68.9 mg/g, respectively, suggesting the addition of g-C3N4/TiO2 (CNT) could notably enhance the acid resistance of CS and widen its practical application. Under visible-light irradiation, the removal efficiency of Cr(VI) using CS/CNT nanofibers was appreciably improved, which was about 50 % higher than that of pure adsorption, indicating that the CS/CNT nanofibers exhibited the effective synergistic effect of adsorption and photocatalysis.

An acid and alkali-resistant triboelectric nanogenerator.

With the development of technology, environmental problems have become more and more acute and the use of electronic devices in harsh environments has gradually attracted attention. For example, the friction layer of triboelectric nanogenerators (TENGs) may be contaminated and corroded in harsh environments (such as acidic, alkaline or oily environments), resulting in damage or destruction of the TENGs. In this study, we use electrospinning followed by a sintering process to prepare a super-hydrophobic sintered polyvinyl alcohol-polytetrafluoroethylene (S-PVA-PTFE) composite membrane and general industrial oil-absorbing paper to construct a TENG. The maximum power density of the TENG is 261 mW m-2, it can light up 100 blue LEDs, and can power a variety of small electronic devices. Moreover, after 72 h of soaking the friction layer in a strong acid solution followed by a strong alkali solution, the performance of the TENG has no obvious change. The TENG can work stably in an oily working environment. The TENG provides a novel approach for self-powered sensors that work in harsh environments.

Stretchable Strain Sensor for Human Motion Monitoring Based on an Intertwined-Coil Configuration.

Wearable electronics, such as sensors, actuators, and supercapacitors, have attracted broad interest owing to their promising applications. Nevertheless, practical problems involving their sensitivity and stretchability remain as challenges. In this work, efforts were devoted to fabricating a highly stretchable and sensitive strain sensor based on dip-coating of graphene onto an electrospun thermoplastic polyurethane (TPU) nanofibrous membrane, followed by spinning of the TPU/graphene nanomembrane into an intertwined-coil configuration. Owing to the intertwined-coil configuration and the synergy of the two structures (nanoscale fiber gap and microscale twisting of the fiber gap), the conductive strain sensor showed a stretchability of 1100%. The self-inter-locking of the sensor prevents the coils from uncoiling. Thanks to the intertwined-coil configuration, most of the fibers were wrapped into the coils in the configuration, thus avoiding the falling off of graphene. This special configuration also endowed our strain sensor with an ability of recovery under a strain of 400%, which is higher than the stretching limit of knees and elbows in human motion. The strain sensor detected not only subtle movements (such as perceiving a pulse and identifying spoken words), but also large movements (such as recognizing the motion of fingers, wrists, knees, etc.), showing promising application potential to perform as flexible strain sensors.

Anisotropic Triboelectric Nanogenerator Based on Ordered Electrospinning.

As a new type of energy harvesting and conversion device, nanogenerator can collect various energies from daily life environment and convert it into electrical energy; it has great flexibility and can provide power for small independent systems. The triboelectric nanogenerator (TENG) is widely concerned because of their high output energy density. However, in the case of an open circuit, there will be static charge accumulation on the friction surface. The high voltage generated by the accumulation of charge on the surface will bring the risk of electrostatic discharge (ESD) to nearby circuits. To solve this problem, we have used the ordered polymer nanofibers obtained by electrospinning technology to form an anisotropic triboelectric nanogenerator with better tensile properties and mechanical strength than disordered electrospinning TENG. By adjusting the effective contact area, the voltage output in the longitudinal direction is one order of magnitude higher than the voltage output in the lateral direction. When not in use, the nanogenerator can be rotated 90°, so static charge accumulation and circuit burnout can be avoided, providing an easy method of preventing ESD in a wearable environment.

Assessment and mechanisms of microalgae growth inhibition by phosphonates: Effects of intrinsic toxicity and complexation.

The effects of phosphonates, the heavily-used antiscalants in reverse osmosis systems, on microalgae are controversial, although they are harmless to most aquatic organisms. Herein, we assessed the inhibitory effects of etidronic acid (HEDP) and diethylenetriamine penta(methylene phosphonic acid) (DTPMP) on algal growth and revealed the mechanisms involved in both intrinsic toxicity and complexation. The phosphonates showed weak influences on Scenedesmus sp. LX1 in the first 4 d of cultivation. In contrast, a significant growth inhibition was observed subsequently with half maximal effective concentrations of 57.6 and 35.7 mg/L for HEDP and DTPMP, respectively, at 10 d. The phosphonates had little effect on cellular energy transfer and oxidative stress, quantified by adenosine triphosphate level and superoxide dismutase activity, respectively, demonstrating weak intrinsic toxicities to algal cells. Phosphonates blocked the algal assimilation of iron ions through complexation. Severe iron deficiency limited photosynthetic activity and caused chlorophyll decline, resulting in a functional loss of the photosystem followed by complete algal growth inhibition at the late cultivation stage. Our findings point to a potential ecological impact wherein harmful algal blooms are induced by the natural degradation of phosphonates due to the release of both iron and phosphate ions that stimulate algal regrowth after disinhibition.

Self-powered portable melt electrospinning for in situ wound dressing.

BACKGROUND: Electrospun (e-spun) nanofibers for wound dressing have attracted wide attention due to its large specific surface area, large porosity and breathability. Compared with solution electrospinning (e-spinning), melt e-spinning is more bio-friendly without toxic solvent participation, which provides the possibility of in situ e-spinning on wounds directly. However, previously reported melt e-spinning devices were usually bulky and cumbersome due to their necessary heating unit, and different components were separated to avoid electrostatic interference. RESULTS: In this article, we report on a self-powered hand-held melt e-spinning gun which can work without any external power supply (outdoors). The problem of electrostatic interference for this integrated device was solved by using a special high heat transfer insulation unit. The apparatus is easy and safe to operate by a single hand due to its small volume (24 × 6 × 13 cm3) and light weight (about 450 g). Some biodegradable polymers, for example, polycaprolactone (PCL) fibers were successful e-spun onto wounds directly by using this dressing gun. CONCLUSIONS: PCL fibrous membrane has good biocompatibility and can be in situ electrospun to wound surface as a wound dressing by the portable melt e-spinning gun. Besides wound dressing, this hand-held melt e-spinning gun may be used in 3D printing and experimental teaching demonstration aids.

Magnetic-Electrospinning Synthesis of γ-Fe2O3 Nanoparticle-Embedded Flexible Nanofibrous Films for Electromagnetic Shielding.

The exploration of a new family of flexible and high-performance electromagnetic shielding materials is of great significance to the next generation of intelligent electronic products. In this paper, we report a simple magnetic-electrospinning (MES) method for the preparation of a magnetic flexible film, γ-Fe2O3 nanoparticle-embedded polymeric nanofibers. By introducing the extra magnetic field force on γ-Fe2O3 nanoparticles within composite fibers, the critical voltage for spinning has been reduced, along with decreased fiber diameters. The MES fibers showed increased strength for the magnetic field alignment of the micro magnets, and the attraction between them assisted the increase in fiber strength. The MES fibers show modifications of the magnetic properties and electrical conductivity, thus leading to better electromagnetic shielding performance.

Enhanced simultaneous removal of nitrogen, phosphorous, hardness, and methylisothiazolinone from reverse osmosis concentrate by suspended-solid phase cultivation of Scenedesmus sp. LX1.

The disposal of reverse osmosis (RO) concentrate (ROC) is a critical challenge impeding the application of RO-based wastewater reclamation. Herein, we proposed an enhanced biotreatment approach for the simultaneous removal of nitrogen, phosphorous, hardness, and methylisothiazolinone (MIT) from ROC by suspended-solid phase cultivation of Scenedesmus sp. LX1. Repeated carrier addition, guided by the developed optimal carrier addition model, efficiently enhanced algal growth and contaminant removal through dynamically controlling the suspended algal density by cell attachment. The maximum algal growth rate (212.2 mg/(L∙d)) increased by 41% compared with the control, and the time needed for reaching the maximum algal biomass (906.7 mg/L) was shortened by 1 d, attributing to the mitigation of density restriction. 91.8% of nitrogen (30.2 mg/L) was removed with 5.5 mg/(L∙d) accelerating removal rate, and phosphate (3.7 mg/L) was completely removed within 1 d. Hardness precursors calcium and inorganic carbon were also removed in large amounts, 268.4 and 128.2 mg/L, respectively. Moreover, suspended-solid phase cultivation significantly mitigated the growth inhibition caused by MIT toxicity, enabled the algae to completely biodegrade MIT of extremely high concentrations (4.7 mg/L and 11.4 mg/L) in a short time. Our results demonstrate the feasibility of suspended-solid phase algal cultivation for simultaneously and effectively removing multiple main contaminants from ROC.

In situ melt electrospun polycaprolactone/Fe3O4 nanofibers for magnetic hyperthermia.

Magnetic fibrous membrane used to generate heat under the alternating magnetic field (AMF) has attracted wide attention due to their application in magnetic hyperthermia. However, there is not magnetic fibrous membrane prepared by melt electrospinning (e-spinning) which is a solvent-free, bio-friendly technology. In this work, polycaprolactone (PCL)/Fe3O4 fiber membrane was prepared by melt e-spinning and using homemade self-powered portable melt e-spinning apparatus. The hand-held melt e-spinning apparatus has a weight of about 450 g and a precise size of 24 cm in length, 6 cm in thickness and 13 cm in height, which is more portable for widely using in the medical field. The PCL/Fe3O4 composite fibers with diameters of 4-17 µm, are very uniform. In addition, the magnetic composite fiber membrane has excellent heating efficiency and thermal cycling characteristics. The results indicated that self-powered portable melt e-spinning apparatus and PCL/Fe3O4 fiber membrane may provide an attractive way for hyperthermia therapy.

Facile Preparation of Highly Stretchable TPU/Ag Nanowire Strain Sensor with Spring-Like Configuration.

Stretchable nano-fibers have attracted dramatic attention for the utility in wearable and flexible electronics. In the present case, Ag nanowires (AgNWs)-intertwined thermoplastic polyurethanes (TPU) unwoven nano-membrane is fabricated by an electrospinning method and dip coating technique. Then a strain sensor with a spring-like configuration is fabricated by a twisted method. The sensor exhibits superior electrical conductivity up to 3990 S cm-1 due to the high weight percentage of the Ag nanowires. Additionally, thanks to the free-standing spring-like configuration that consists of uniform neat loops, the strain sensor can detect a superior strain up to 900% at the point the sensor ruptures. On the other hand, the configuration can mostly protect the AgNWs from falling off. Furthermore, major human motion detection, like movement of a human forefinger, and minor human motion detection, such as a wrist pulse, show the possible application of the sensor in the field of flexible electronics.

Wireless Single-Electrode Self-Powered Piezoelectric Sensor for Monitoring.

In complex environments, there are often toxic and harmful conditions, and so self-powered sensors that use wireless access have a huge advantage. However, there is still a risk of short circuit for self-powered sensors in harsh environments. A single-electrode self-powered sensor was designed, which can be used to monitor body movements such as walking and running, as well as monitoring the motion of some mechanical devices, such as peristaltic pumps, door, and window switches. By using a threshold delay algorithm, this self-powered sensor can be connected to the phone to warn the phone user to check for theft or illegal intrusion when the door and window are opened. Further research shows that the single-electrode configuration can avoid the short-circuit behavior caused by device damage so that the self-powered sensor can still work even if it is pierced. Therefore, the wireless single-electrode self-powered sensor system has better reliability and is more applicable to harsh environments.

Mechanism and kinetics of methylisothiazolinone removal by cultivation of Scenedesmus sp. LX1.

Methylisothiazolinone (MIT) is a widely used non-oxidizing biocide for membrane biofouling control in reverse osmosis (RO) systems usually with high dosages. However, few investigations have focused on MIT removal through bio-processes, since it is highly bio-toxic. This study proposed a novel biotreatment approach for efficient MIT degradation by Scenedesmus sp. LX1, a microalga with strong resistance capability against extreme MIT toxicity. Results showed that MIT (3 mg/L) could be completely removed within 4 days' cultivation with a half-life of only 0.79 d. Biodegradation was the primary removal mechanism and this metabolic process did not rely on bacterial consortia, soluble algal products secretion or algal growth. The main pathway was proposed as ring cleavage followed by methylation and carboxylation through the identification of MIT transformation products. MIT biodegradation followed the pseudo-first-order kinetics under growth control. A new kinetic model was presented to depict the MIT removal considering algal growth, and this model could be used for generally describing non-nutritive contaminants biodegradation. The algal biodegradation capability was independent of the initial biocide concentration, and MIT removal could be enhanced by increasing the initial algal density. Our results highlight the potential application of algal cultivation for MIT-containing wastewater biotreatment, such as RO concentrate.

Transparent Polyurethane Nanofiber Air Filter for High-Efficiency PM2.5 Capture.

Fine particulate matter (PM) has seriously affected human life, such as affecting human health, climate, and ecological environment. Recently, many researchers use electrospinning to prepare nanofiber air filters for effective removal of fine particle matter. However, electrospinning of the polymer fibers onto the window screen uniformly is only achieved in the laboratory, and the realization of industrialization is still very challenging. Here, we report an electrospinning method using a rotating bead spinneret for large-scale electrospinning of thermoplastic polyurethane (TPU) onto conductive mesh with high productivity of 1000 m2/day. By changing the concentration of TPU in the polymer solution, PM2.5 removal efficiency of nanofiber-based air filter can be up to 99.654% with good optical transparency of 60%, and the contact angle and the ventilation rate of the nanofiber-based air filter is 128.5° and 3480 mm/s, respectively. After 10 times of filtration, the removal efficiency is only reduced by 1.6%. This transparent air filter based on TPU nanofibers has excellent filtration efficiency and ventilation rate, which can effectively ensure indoor air quality of the residential buildings.

Recent Advances in Hemostasis at the Nanoscale.

Rapid and effective hemostatic materials have received wide attention not only in the battlefield but also in hospitals and clinics. Traditional hemostasis relies on materials with little designability which has many limitations. Nanohemostasis has been proposed since the use of peptides in hemostasis. Nanomaterials exhibit excellent adhesion, versatility, and designability compared to traditional materials, laying a good foundation for future hemostatic materials. This review first summarizes current hemostatic methods and materials, and then introduces several cutting-edge designs and applications of nanohemostatic materials such as polypeptide assembly, electrospinning of cyanoacrylate, and nanochitosan. Particularly, their advantages and working mechanisms are introduced. Finally, the challenges and prospects of nanohemostasis are discussed.