One‐Step,Room‐Temperature Synthesis of Glutathione‐Capped Iron‐Oxide Nanoparticles and their Application in In Vivo T1‐Weighted Magnetic Resonance Imaging

The room‐temperature, aqueous‐phase synthesis of iron‐oxide nanoparticles (IO NPs) with glutathione (GSH) is reported. The simple, one‐step reduction involves GSH as a capping agent and tetrakis(hydroxymethyl)phosphonium chloride (THPC) as the reducing agent; GSH is an anti‐oxidant that is abundant in the human body while THPC is commonly used in the synthesis of noble‐metal clusters. Due to their low magnetization and good water‐dispersibility, the resulting GSH‐IO NPs, which are 3.72 ± 0.12 nm in diameter, exhibit a low r₂ relaxivity (8.28 mm ^?1s^?1) and r₂/r₁ ratio (2.28)—both of which are critical for T₁ contrast agents. This, together with the excellent biocompatibility, makes these NPs an ideal candidate to be a T₁ contrast agent. Its capability in cellular imaging is illustrated by the high signal intensity in the T₁‐weighted magnetic resonance imaging (MRI) of treated HeLa cells. Surprisingly, the GSH‐IO NPs escape ingestion by the hepatic reticuloendothelial system, enabling strong vascular enhancement at the internal carotid artery and superior sagittal sinus, where detection of the thrombus is critical for diagnosing a stroke. Moreover, serial T₁‐ and T₂‐weighted time‐dependent MR images are resolved for a rat's kidneys, unveiling detailed cortical‐medullary anatomy and renal physiological functions. The newly developed GSH‐IO NPs thus open a new dimension in efforts towards high‐performance, long‐circulating MRI contrast agents that have biotargeting potential.     

On the performance of high‐order finite elements with respect to maximum principles and the nonnegative constraint for diffusion‐type equations

The main aim of this paper is to document the performance of p‐refinement with respect to maximum principles and the nonnegative constraint. The model problem is steady‐state anisotropic diffusion with decay (which is a second‐order elliptic partial differential equation). We consider the standard single‐field formulation based on the Galerkin formalism and two least squares‐based mixed formulations. We employ Lagrange polynomials with unequal‐spaced points, and polynomials of order p = 1 to p = 10 are used. It is shown that the violation of the nonnegative constraint cannot be overcome with p‐refinement alone for anisotropic diffusion. We shall illustrate the performance of p‐refinement by using several representative problems. The intended outcomes of the paper are twofold. First, this study will caution the users of high‐order approximations about their performance with respect to maximum principles and the nonnegative constraint. Second, this study will help researchers develop new methodologies for enforcing maximum principles and the nonnegative constraint under high‐order approximations. Copyright © 2012 John Wiley & Sons, Ltd.     

Variations in BOLD response latency estimated from event‐related fMRI at 3T: Comparisons between gradient‐echo and Spin‐echo

Functional magnetic resonance imaging (fMRI) commonly uses gradient‐recalled echo (GRE) signals to detect regional hemodynamic variations originating from neural activities. While the spatial localization of activation shows promising applications, indexing temporal response remains a poor mechanism for detecting the timing of neural activity. Particularly, the hemodynamic response may fail to resolve sub‐second temporal differences between brain regions because of its signal origin or noise in data, or both. This study aimed at evaluating the performance of latency estimation using different fMRI techniques, with two event‐related experiments at 3T. Experiment I evaluated latency variations within the visual cortex and their relationship with contrast‐to‐noise ratios (CNRs) for GRE, spin echo (SE), and diffusion‐weighted SE (DWSE). Experiment II used delayed visual stimuli between two hemifields (delay time = 0, 250, and 500 ms, respectively) to assess the temporal resolving power of three protocols: GRE_TR1000, GRE_TR500, and SE_TR1000. The results of experiment I showed the earliest latency with DWSE, followed by SE, and then GRE. Latency variations decreased as CNR increased. However, similar variations were found between GRE and SE, when the latter had lower CNR. In experiment II, measured stimulus delays from all conditions were significantly correlated with preset stimulus delays. Inter‐subject variation in the measured delay was found to be greatest with GRE_TR1000, followed by GRE_TR500, and the least with SE_TR1000. Conclusively, blood oxygenation level‐dependent responses obtained from GRE exhibit greater CNR but no compromised latency variations in the visual cortex. SE is potentially capable of improving the performance of latency estimation, especially for group analysis. © 2013 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 23, 215–221, 2013     

Phosphorus‐Mediated MoS2 Nanowires as a High‐Performance Electrode Material for Quasi‐Solid‐State Sodium‐Ion Intercalation Supercapacitors

Molybdenum disulfide (MoS₂) is a promising electrode material for electrochemical energy storage owing to its high theoretical specific capacity and fascinating 2D layered structure. However, its sluggish kinetics for ionic diffusion and charge transfer limits its practical applications. Here, a promising strategy is reported for enhancing the Na⁺‐ion charge storage kinetics of MoS₂ for supercapacitors. In this strategy, electrical conductivity is enhanced and the diffusion barrier of Na⁺ ion is lowered by a facile phosphorus‐doping treatment. Density functional theory results reveal that the lowest energy barrier of dilute Na‐vacancy diffusion on P‐doped MoS₂ (0.11 eV) is considerably lower than that on pure MoS₂ (0.19 eV), thereby signifying a prominent rate performance at high Na intercalation stages upon P‐doping. Moreover, the Na‐vacancy diffusion coefficient of the P‐doped MoS₂ at room temperatures can be enhanced substantially by approximately two orders of magnitude (10^?6–10^?4 cm² s^?1) compared with pure MoS₂. Finally, the quasi‐solid‐state asymmetrical supercapacitor assembled with P‐doped MoS₂ and MnO₂, as the positive and negative electrode materials, respectively, exhibits an ultrahigh energy density of 67.4 W h kg^?1 at 850 W kg^?1 and excellent cycling stability with 93.4% capacitance retention after 5000 cycles at 8 A g^?1.     

Magnetic resonance scan‐time reduction using echo prediction

A linear prediction (LP) filter derived from a complete echo with zero‐phase encoding amplitude is used for recovering anatomical details from a partially acquired echo sequence. The LP filter is shown to reconstruct missing k‐space phase and amplitude information, with errors sufficiently low so as to provide image reconstruction with a contrast‐to‐noise ratio (CNR) ≥ 3. For volume imaging using multislice acquisition, the partial‐echo sequence enables more number of slices to be acquired for a given repetition time period T_R. For such sequences, separate predictors are used for reconstruction of missing k‐space data corresponding to each individual slice in the volume. The proposed filtering scheme is shown to achieve results comparable to other partial k‐space approaches such as singularity function analysis (SFA), when the noise content is less than about 0.4%. For higher noise levels, this technique is recommended as a preprocessing step for SFA to track the singularity locations more accurately. © 2013 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 23, 1–8, 2013     

Low‐Density Lipoprotein‐Mimicking Nanoparticles for Tumor‐Targeted Theranostic Applications

This study introduces multifunctional lipid nanoparticles (LNPs), mimicking the structure and compositions of low‐density lipoproteins, for the tumor‐targeted co‐delivery of anti‐cancer drugs and superparamagnetic nanocrystals. Paclitaxel (4.7 wt%) and iron oxide nanocrystals (6.8 wt%, 11 nm in diameter) are co‐encapsulated within folate‐functionalized LNPs, which contain a cluster of nanocrystals with an overall diameter of about 170 nm and a zeta potential of about ‐40 mV. The folate‐functionalized LNPs enable the targeted detection of MCF‐7, human breast adenocarcinoma expressing folate receptors, in T₂‐weighted magnetic resonance images as well as the efficient intracellular delivery of paclitaxel. Paclitaxel‐free LNPs show no significant cytotoxicity up to 0.2 mg mL^?1, indicating the excellent biocompatibility of the LNPs for intracellular drug delivery applications. The targeted anti‐tumor activities of the LNPs in a mouse tumor model suggest that the low‐density lipoprotein‐mimetic LNPs can be an effective theranostic platform with excellent biocompatibility for the tumor‐targeted co‐delivery of various anti‐cancer agents.     

Hierarchical Composite of Rose‐Like VS2@S/N‐Doped Carbon with Expanded (001) Planes for Superior Li‐Ion Storage

In the present work, a hierarchical composite of rose‐like VS₂@S/N‐doped carbon (VS₂@SNC) with expanded (001) planes is successfully fabricated through a facile synthetic route. Notably, the d‐spacing of (001) planes is expanded to 0.92 nm, which is proved to dramatically reduce the energy barrier for Li⁺ diffusion in the composite of VS₂@SNC by density functional theory calculation. On the other hand, the S/N‐doped carbon in the composite greatly promotes the electrical conductivity and enhances the structural stability. In addition, the hierarchical structure of VS₂@SNC facilitates rapid electrolyte diffusion and increases the contact area between the electrode and electrolyte simultaneously. Benefiting from the merits mentioned above, the VS₂@SNC electrode exhibits excellent electrochemical properties, such as a large reversible capacity of 971.6 mA h g^?1 at 0.2 A g^?1, an extremely high rate capability of 772.1 mA h g^?1 at 10 A g^?1, and a remarkable cycling stability up to 600 cycles at 8 A g^?1 with a capacity of 684.5 mA h g^?1, making it a promising candidate as an anode material for lithium‐ion batteries.     

Pseudocapacitance of TiO2−x/CNT Anodes for High‐Performance Quasi‐Solid‐State Li‐Ion and Na‐Ion Capacitors

It is challenging for flexible solid‐state hybrid capacitors to achieve high‐energy‐high‐power densities in both Li‐ion and Na‐ion systems, and the kinetics discrepancy between the sluggish faradaic anode and the rapid capacitive cathode is the most critical issue needs to be addressed. To improve Li‐ion/Na‐ion diffusion kinetics, flexible oxygen‐deficient TiO_2?x/CNT composite film with ultrafast electron/ion transport network is constructed as self‐supported and light‐weight anode for a quasi‐solid‐state hybrid capacitor. It is found that the designed porous yolk–shell structure endows large surface area and provides short diffusion length, the oxygen‐deficient composite film can improve electrical conductivity, and enhance ion diffusion kinetic by introducing intercalation pseudocapacitance, therefore resulting in advance electrochemical properties. It exhibits high capacity, excellent rate performance, and long cycle life when utilized as self‐supported anodes for Li‐ion and Na‐ion batteries. When assembled with activated carbon/carbon nanotube (AC/CNT) flexible cathode, using ion conducting gel polymer as the electrolyte, high energy densities of 104 and 109 Wh kg^?1 are achieved at 250 W kg^?1 in quasi‐solid‐state Li‐ion and Na‐ion capacitors (LICs and SICs), respectively. Still, energy densities of 32 and 36 Wh kg^?1 can be maintained at high power densities of 5000 W kg^?1 in LICs and SICs.     

High‐Performance Upconversion Nanoprobes for Multimodal MR Imaging of Acute Ischemic Stroke

Multimodal magnetic resonance (MR) imaging, including MR angiography (MRA) and MR perfusion (MRP), plays a critical role in the diagnosis and surveillance of acute ischemic stroke. However, these techniques are hindered by the low T₁ relaxivity, short circulation time, and high leakage rate from vessels of clinical Magnevist. To address these problems, nontoxic polyethylene glycol (PEG)ylated upconversion nanoprobes (PEG‐UCNPs) are synthesized and first adopted for excellent MRA and MRP imaging, featuring high diagnostic sensitivity toward acute ischemic stroke in high‐resolution imaging. The investigations show that the agent possesses superior advantages over clinical Magnevist, such as much higher relaxivity, longer circulation time, and lower leakage rate, which guarantee much better imaging efficiency. Remarkably, an extremely small dosage (5 mg Gd kg^?1) of PEG‐UCNPs provides high‐resolution MRA imaging with the vascular system delineated much clearer than the Magnevist with clinical dosage as high as 108 mg Gd kg^?1. On the other hand, the long circulation time of PEG‐UCNPs enables the surveillance of the progression of ischemic stroke using MRA or MRP. Once translated, these PEG‐UCNPs are expected to be a promising candidate for substituting the clinical Magnevist in MRA and MRP, which will significantly lengthen the imaging time window and improve the overall diagnostic efficiency.     

Thiazole Imide‐Based All‐Acceptor Homopolymer: Achieving High‐Performance Unipolar Electron Transport in Organic Thin‐Film Transistors

High‐performance unipolar n‐type polymer semiconductors are critical for advancing the field of organic electronics, which relies on the design and synthesis of new electron‐deficient building blocks with good solubilizing capability, favorable geometry, and optimized electrical properties. Herein, two novel imide‐functionalized thiazoles, 5,5′‐bithiazole‐4,4′‐dicarboxyimide (BTzI) and 2,2′‐bithiazolothienyl‐4,4′,10,10′‐tetracarboxydiimide (DTzTI), are successfully synthesized. Single crystal analysis and physicochemical study reveal that DTzTI is an excellent building block for constructing all‐acceptor homopolymers, and the resulting polymer poly(2,2′‐bithiazolothienyl‐4,4′,10,10′‐tetracarboxydiimide) (PDTzTI) exhibits unipolar n‐type transport with a remarkable electron mobility (μ_e) of 1.61 cm² V^?1 s^?1, low off‐currents (I_off) of 10^?10?10^?11 A, and substantial current on/off ratios (I_on/I_off) of 10⁷?10⁸ in organic thin‐film transistors. The all‐acceptor homopolymer shows distinctive advantages over prevailing n‐type donor?acceptor copolymers, which suffer from ambipolar transport with high I_offs > 10^?8 A and small I_on/I_offs < 10⁵. The results demonstrate that the all‐acceptor approach is superior to the donor?acceptor one, which results in unipolar electron transport with more ideal transistor performance characteristics.     

Ten‐Gram‐Scale Facile Synthesis of Organogadolinium Complex Nanoparticles for Tumor Diagnosis

The market of available contrast agents for clinical magnetic resonance imaging (MRI) has been dominated by gadolinium (Gd) chelates based T₁ contrast agents for decades. However, there are growing concerns about their safety because they are retained in the body and are nephrotoxic, which necessitated a warning by the U.S. Food and Drug Administration against the use of such contrast agents. To ameliorate these problems, it is necessary to improve the MRI efficiency of such contrast agents to allow the administration of much reduced dosages. In this study, a ten‐gram‐scale facile method is developed to synthesize organogadolinium complex nanoparticles (i.e., reductive bovine serum albumin stabilized Gd‐salicylate nanoparticles, GdSalNPs‐rBSA) with high r₁ value of 19.51 mm ^?1 s^?1 and very low r₂/r₁ ratio of 1.21 (B₀ = 1.5 T) for high‐contrast T₁‐weighted MRI of tumors. The GdSalNPs‐rBSA nanoparticles possess more advantages including low synthesis cost (≈0.54 USD per g), long in vivo circulation time (t_1/2 = 6.13 h), almost no Gd³⁺ release, and excellent biosafety. Moreover, the GdSalNPs‐rBSA nanoparticles demonstrate excellent in vivo MRI contrast enhancement (signal‐to‐noise ratio (ΔSNR) ≈ 220%) for tumor diagnosis.     

Cyanine‐Anchored Silica Nanochannels for Light‐Driven Synergistic Thermo‐Chemotherapy

Smart nanoparticles are increasingly important in a variety of applications such as cancer therapy. However, it is still a major challenge to develop light‐responsive nanoparticles that can maximize the potency of synergistic thermo‐chemotherapy under light irradiation. Here, spatially confined cyanine‐anchored silica nanochannels loaded with chemotherapeutic doxorubicin (CS‐DOX‐NCs) for light‐driven synergistic cancer therapy are introduced. CS‐DOX‐NCs possess a J‐type aggregation conformation of cyanine dye within the nanochannels and encapsulate doxorubicin through the π–π interaction with cyanine dye. Under near‐infrared light irradiation, CS‐DOX‐NCs produce the enhanced photothermal conversion efficiency through the maximized nonradiative transition of J‐type Cypate aggregates, trigger the light‐driven drug release through the destabilization of temperature‐sensitive π–π interaction, and generate the effective intracellular translocation of doxorubicin from the lysosomes to cytoplasma through reactive oxygen species‐mediated lysosomal disruption, thereby causing the potent in vivo hyperthermia and intracellular trafficking of drug into cytoplasma at tumors. Moreover, CS‐DOX‐NCs possess good resistance to photobleaching and preferable tumor accumulation, facilitating severe photoinduced cell damage, and subsequent synergy between photothermal and chemotherapeutic therapy with tumor ablation. These findings provide new insights of light‐driven nanoparticles for synergistic cancer therapy.     

Low‐Dimensional Perovskites with Diammonium and Monoammonium Alternant Cations for High‐Performance Photovoltaics

Low‐dimensional Ruddlesden–Popper (LDRP) perovskites are a current theme in solar energy research as researchers attempt to fabricate stable photovoltaic devices from them. However, poor exciton dissociation and insufficiently fast charge transfer slows the charge extraction in these devices, resulting in inferior performance. 1,4‐Butanediamine (BEA)‐based low‐dimensional perovskites are designed to improve the carrier extraction efficiency in such devices. Structural characterization using single‐crystal X‐ray diffraction reveals that these layered perovskites are formed by the alternating ordering of diammonium (BEA²⁺) and monoammonium (MA⁺) cations in the interlayer space (B‐ACI) with the formula (BEA)_0.5MA_n PbnI_3n+1. Compared to the typical LDRP counterparts, these B‐ACI perovskites deliver a wider light absorption window and lower exciton binding energies with a more stable layered perovskite structure. Additionally, ultrafast transient absorption indicates that B‐ACI perovskites exhibit a narrow distribution of quantum well widths, leading to a barrier‐free and balanced carrier transport pathway with enhanced carrier diffusion (electron and hole) length over 350 nm. A perovskite solar cell incorporating BEA ligands achieves record efficiencies of 14.86% for (BEA)_0.5MA₃Pb₃I₁₀ and 17.39% for (BEA)_0.5Cs_0.15(FA_0.83MA_0.17)_2.85Pb₃(I_0.83Br_0.17)₁₀ without hysteresis. Furthermore, the triple cations B‐ACI devices can retain over 90% of their initial power conversion efficiency when stored under ambient atmospheric conditions for 2400 h and show no significant degradation under constant illumination for over 500 h.     

Multifunctional Magnetic Gd3+‐Based Coordination Polymer Nanoparticles: Combination of Magnetic Resonance and Multispectral Optoacoustic Detections for Tumor‐Targeted Imaging in vivo

To overcome traditional barriers in optical imaging and microscopy, optoacoustic‐imaging has been changed to combine the accuracy of spectroscopy with the depth resolution of ultrasound, achieving a novel modality with powerful in vivo imaging. However, magnetic resonance imaging provides better spatial and anatomical resolution. Thus, a single hybrid nanoprobe that allows for simultaneous multimodal imaging is significant not only for cutting edge research in imaging science, but also for accurate clinical diagnosis. A core‐shell‐structured coordination polymer composite microsphere has been designed for in vivo multimodality imaging. It consists of a Fe₃O₄ nanocluster core, a carbon sandwiched layer, and a carbocyanine‐Gd^III (Cy‐Gd^III) coordination polymer outer shell (Fe₃O₄@C@Cy‐Gd^III). Folic acid‐conjugated poly(ethylene glycol) chains are embedded within the coordination polymer shell to achieve extended circulation and targeted delivery of probe particles in vivo. Control of Fe₃O₄ core grain sizes results in optimal r₂ relaxivity (224.5 × 10^–3 m ⁻¹ s^‐1) for T₂‐weighted magnetic resonance imaging. Cy‐Gd^III coordination polymers are also regulated to obtain a maximum 25.1% of Cy ligands and 5.2% of Gd^III ions for near‐infrared fluorescence and T₁‐weighted magnetic resonance imaging, respectively. The results demonstrate their impressive abilities for targeted, multimodal, and reliable imaging.     

In Vivo MR Imaging of Glioma Recruitment of Adoptive T‐Cells Labeled with NaGdF4‐TAT Nanoprobes

Adoptive T lymphocyte immunotherapy is one of the most promising methods to treat residual lesions after glioma surgery. However, the fate of the adoptively transferred T‐cells in vivo is unclear, hampering the understanding of this emerging therapy. Thus, it is highly desirable to develop noninvasive and quantitative in vivo tracking of these T‐cells to glioma for better identification of the migratory fate and to provide objective evaluation of outcomes of adoptive T‐cell immunotherapy targeting glioma. In this work, ultrasmall T₁ MR‐based nanoprobes, NaGdF₄‐TAT, as molecular probes with high longitudinal relaxivity (8.93 mm ^?1 s^?1) are designed. By means of HIV‐1 transactivator (TAT) peptides, nearly 95% of the adoptive T‐cells are labeled with the NaGdF₄‐TAT nanoprobes without any measurable side effects on the labeled T‐cells, which is remarkably superior to that of the control fluorescein isothiocyanate‐NaGdF₄ concerning labeling efficacy. Labeled adoptive T‐cell clusters can be sensitively tracked in an orthotopic GL261‐glioma model 24 h after intravenous infusion of 10⁷ labeled T‐cells by T₁‐weighted MR imaging. Both in vitro and in vivo experiments show that the NaGdF₄‐TAT nanoprobes labeling of T‐cells may be a promising method to track adoptive T‐cells to improve our understanding of the pathophysiology in adoptive immunotherapy for gliomas.     

User‐friendly image sharing using polynomials with different primes

Recently, Thien and Lin proposed a user‐friendly (k, n)‐threshold scheme which employs Lagrange interpolation to produce shadow images representing a shrunken version of the original image. In this paper, we introduce a new framework which uses more (k ? 1)‐degree polynomials with different primes to enhance the functionality of the user‐friendly (k, n)‐threshold framework and obtain more effective performance for large k. Since the proposed framework significantly reduces reconstruction errors compared to the previously published user‐friendly schemes, it is suitable for modern visual communication applications where features such as distributed trust, secure transmission and storage, fault tolerance, and high‐quality image reconstruction are required. © 2007 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 17, 40–47, 2007     

A rapid simulation of nano‐particle transport in a two‐dimensional human airway using POD/Galerkin reduced‐order models

An approach is proposed for the rapid prediction of nano‐particle transport and deposition in the human airway, which requires the solution of both the Navier–Stokes and advection–diffusion equations and for which computational efficiency is a challenge. The proposed method builds low‐order models that are representative of the fully coupled equations by means of the Galerkin projection and proper orthogonal decomposition technique. The obtained reduced‐order models (ROMs) are a set of ordinary differential equations for the temporal coefficients of the basis functions. The numerical results indicate that the ROMs are highly efficient for the computation (the speedup factor is approximately 3 × 10³) and have reasonable accuracy compared with the full model (relative error of ≈7 × 10^?3). Using ROMs, the deposition of particles is studied for 1≤d_n≤100 nm, where d_n is the diameter of a nano‐particle. The effectiveness of this approach is promising for applications of health risk assessment. Copyright © 2015 John Wiley & Sons, Ltd.     

Tri‐s‐triazine‐Based Crystalline Carbon Nitride Nanosheets for an Improved Hydrogen Evolution

Tri‐s‐triazine‐based crystalline carbon nitride nanosheets (CCNNSs) have been successfully extracted via a conventional and cost‐effective sonication–centrifugation process. These CCNNSs possess a highly defined and unambiguous structure with minimal thickness, large aspect ratios, homogeneous tri‐s‐triazine‐based units, and high crystallinity. These tri‐s‐triazine‐based CCNNSs show significantly enhanced photocatalytic hydrogen generation activity under visible light than g‐C₃N₄, poly (triazine imide)/Li⁺ Cl^–, and bulk tri‐s‐triazine‐based crystalline carbon nitrides. A highly apparent quantum efficiency of 8.57% at 420 nm for hydrogen production from aqueous methanol feedstock can be achieved from tri‐s‐triazine‐based CCNNSs, exceeding most of the reported carbon nitride nanosheets. Benefiting from the inherent structure of 2D crystals, the ultrathin tri‐s‐triazine‐based CCNNSs provide a broad range of application prospects in the fields of bioimaging, and energy storage and conversion.     

Vertically Oriented Graphene Nanoribbon Fibers for High‐Volumetric Energy Density All‐Solid‐State Asymmetric Supercapacitors

Graphene fiber based micro‐supercapacitors (GF micro‐SCs) have attracted great attention for their potential applications in portable and wearable electronics. However, due to strong π–π stacking of nanosheets for graphene fibers, the limited ion accessible surface area and slow ion diffusion rate leads to low specific capacitance and poor rate performance. Here, the authors report a strategy for the synthesis of a vertically oriented graphene nanoribbon fiber with highly exposed surface area through confined‐hydrothermal treatment of interconnected graphene oxide nanoribbons and consequent laser irradiation process. As a result, the as‐obtained fiber shows high length specific capacitance of 3.2 mF cm^?1 and volumetric capacitance of 234.8 F cm^?3 at 2 mV s^?1, as well as excellent rate capability and outstanding cycling performance (96% capacitance retention after 10 000 cycles). Moreover, an all‐solid‐state asymmetric supercapacitor based on graphene nanoribbon fiber as negative electrode and MnO₂ coated graphene ribbon fiber as positive electrode, shows high volumetric capacitance and energy density of 12.8 F cm^?3 and 5.7 mWh cm^?3 (normalized to the device volume), respectively, much higher than those of previously reported GF micro‐SCs, as well as a long cycle life with 88% of capacitance retention after 10 000 cycles.