Developmental trajectory of depressive symptoms among left-behind adolescents: The effects of parent-adolescent separation and parent-adolescent cohesion.

INTRODUCTION: Left-behind adolescents are vulnerable to depressive symptoms under the context of parent-adolescent separation. However, limited knowledge is available regarding left-behind adolescents' depression trajectory and the protective resources against it. The aim of this longitudinal study was to investigate the depression trajectory and its association with parent-adolescent separation (left-behind status, age of separation and duration of separation) and parent-adolescent cohesion (father-adolescent cohesion, mother-adolescent cohesion) among left-behind adolescents. METHODS: The participants were 1,107 left-behind adolescents (Mage = 13.23 ± 0.86 years at T1; 45.17% girls; 38.48% both-parent migrant adolescents, 61.52% father-only migrant adolescents) from two rural areas of Shandong Province in China, who were participated in assessment at three time points with 6 months apart from November 2014 to November 2015. RESULTS: The results indicated that the trajectory of left-behind adolescents' depression symptoms showed a decreasing trend. Both-parent migrant adolescents reported a higher initial level of depressive symptoms than father-only migrant adolescents. Duration of separation positively predicted the initial level of left-behind adolescents' depressive symptoms. Mother-adolescent cohesion negatively predicted the initial level and positively predicted the change rate of left-behind adolescents' depressive symptoms. Moreover, mother-adolescent and father-adolescent cohesion buffered the negative effect of parent-adolescent separation on the initial level of left-behind adolescents' depressive symptoms. CONCLUSIONS: These findings highlight the protective role of parent-adolescent cohesion for left-behind adolescents, having important implications for interventions targeted toward mitigating the detrimental influence of parent-adolescent separation on left-behind adolescents' depression trajectory.

Does Parasympathetic Nervous System Activity Exacerbate Depressive Symptoms in College Students Who Experienced Parent-Child Separation? A Longitudinal Examination.

Childhood separation caused by parental migration increases the risk of suffering depressive symptoms among college students. However, most studies in this field have focused on environmental factors and largely ignored the role of physiological reactivity to stress (e.g., parasympathetic nervous system activity) in this process. The present study examined the long-term effects of the parent-child separation experience on depressive symptoms in college students, and explored the moderating role of parasympathetic nervous system (PNS) activity in these relationships. The participants were 242 college students (Mage = 18.74 years, SD = 0.79; 32.2% male), including 149 college students who experienced parent-child separation and 93 college students without this experience. Using a three-wave longitudinal design, participants completed the measures of the parent-child separation experience, PNS activity (measured via respiratory sinus arrhythmia, RSA), and depressive symptoms at Time 1 (T1, before the COVID-19 lockdown). Their depressive symptoms were again measured at Time 2 (T2, during the COVID-19 lockdown) and Time 3 (T3, after the COVID-19 lockdown). The results showed that the parent-child separation experience positively predicted depressive symptoms in college students at three time points. Moreover, the parent-child separation experience positively predicted depressive symptoms at T2 among males with less and average RSA suppression but positively predicted depressive symptoms at T2 among females with greater RSA suppression. These findings indicate a long-term effect of parent-child separation on depressive symptoms in college students that still exist after they entered university, and that the effect varies depending on PNS activity and gender.

Unlocking Double Redox Reaction of Metal-Organic Framework for Aqueous Zinc-Ion Battery.

Metal-organic frameworks (MOFs) show wide application as the cathode of aqueous zinc-ion batteries (AZIBs) in the future owning to their high porosity, diverse structures, abundant species, and controllable morphology. However, the low energy density and poor cycling stability hinder the feasibility in practical application. Herein, an innovative strategy of organic/inorganic double electroactive sites is proposed and demonstrated to obtain extra capacity and enhance the energy density in a manganese-based metal-organic framework (Mn-MOF-74). Simultaneously, its energy storage mechanism is systematically investigated. Moreover, profiting from the coordination effect, the Mn-MOF-74 features with stable structure in ZnSO4 electrolyte. Therefore, the Zn/Mn-MOF-74 batteries exhibit a high energy density and superior cycling stability. This work aids in the future development of MOFs in AZIBs.

Metrnl deficiency retards skin wound healing in mice by inhibiting AKT/eNOS signaling and angiogenesis.

Meteorin-like (Metrnl) is a novel secreted protein with various biological activities. In this study, we investigated whether and how Metrnl regulated skin wound healing in mice. Global Metrnl gene knockout mice (Metrnl-/-) and endothelial cell-specific Metrnl gene knockout mice (EC-Metrnl-/-) were generated. Eight-mm-diameter full-thickness excisional wound was made on the dorsum of each mouse. The skin wounds were photographed and analyzed. In C57BL/6 mice, we observed that Metrnl expression levels were markedly increased in skin wound tissues. We found that both global and endothelial cell-specific Metrnl gene knockout significantly retarded mouse skin wound healing, and endothelial Metrnl was the key factor affecting wound healing and angiogenesis. The proliferation, migration and tube formation ability of primary human umbilical vein endothelial cells (HUVECs) were inhibited by Metrnl knockdown, but significantly promoted by addition of recombinant Metrnl (10 ng/mL). Metrnl knockdown abolished the proliferation of endothelial cells stimulated by recombinant VEGFA (10 ng/mL) but not by recombinant bFGF (10 ng/mL). We further revealed that Metrnl deficiency impaired VEGFA downstream AKT/eNOS activation in vitro and in vivo. The damaged angiogenetic activity in Metrnl knockdown HUVECs was partly rescued by addition of AKT activator SC79 (10 µM). In conclusion, Metrnl deficiency retards skin wound healing in mice, which is related to impaired endothelial Metrnl-mediated angiogenesis. Metrnl deficiency impairs angiogenesis by inhibiting AKT/eNOS signaling pathway.

Kirschner wire versus external fixation in the treatment of proximal humeral fractures in older children and adolescents: a comparative study.

OBJECTIVE: The purpose of this study was to compare the therapeutic effects of Kirschner wire fixation and external fixation in the treatment of proximal humeral fractures in older children and adolescents. METHODS: A retrospective analysis was performed on the clinical data of older children and adolescents who underwent surgery at our institution for proximal humeral fractures between April 2014 and May 2022. One group (n = 28) underwent fracture reduction and Kirschner wire fixation, and the other group (n = 23) underwent external fixation. During the follow-up, the differences in shoulder joint function between the two groups were compared by analysing Quick Disabilities of the Arm, Shoulder, and Hand (Quick DASH) and Constant-Murley scores. Postoperative complications were also recorded. RESULTS: The operation time of the Kirschner wire group was shorter than that of the external fixation group (69.07 ± 11.34 min vs. 77.39 ± 15.74 min, P = 0.33). The time to remove the fixator in the external fixation group was shorter than that in the Kirschner wire group (6.74 ± 1.57 vs. 7.61 ± 1.22, P = 0.032). The Quick DASH score and Constant-Murley score of the patients in the external fixation group were significantly better than those in the Kirschner wire group at 3 months after surgery (5.63 ± 4.33 vs. 8.93 ± 6.40, P = 0.040; 93.78 ± 2.43 vs. 91.75 ± 2.15, P = 0.003). There was no significant difference in the Quick DASH score or Constant-Murley score between the patients in the external fixator group and those in the Kirschner wire group at 9 months after the operation (2.77 ± 3.14 vs. 3.17 ± 3.68, P = 0.683; 97.39 ± 1.80 vs. 96.57 ± 2.15, P = 0.152). The most common complication of the two groups was pin tract infection. The incidence rate of infection was higher in the external fixation group than that in the Kirschner wire group (9 vs. 4, P = 0.043). CONCLUSION: Both Kirschner wire fixation and external fixation of N-H III and IV proximal humeral fractures in older children and adolescents produce good outcomes. External fixation is a preferred surgical treatment option for paediatric proximal humerus fractures because early mobilization of the affected limb can be realized.

An Adaptive Multi-Mode Navigation Method with Intelligent Virtual Sensor Based on Long Short-Term Memory in GNSS Restricted Environment.

Aiming at the problem of fast divergence of pure inertial navigation system without correction under the condition of GNSS restricted environment, this paper proposes a multi-mode navigation method with an intelligent virtual sensor based on long short-term memory (LSTM). The training mode, predicting mode, and validation mode for the intelligent virtual sensor are designed. The modes are switching flexibly according to GNSS rejecting situation and the status of the LSTM network of the intelligent virtual sensor. Then the inertial navigation system (INS) is corrected, and the availability of the LSTM network is also maintained. Meanwhile, the fireworks algorithm is adopted to optimize the learning rate and the number of hidden layers of LSTM hyperparameters to improve the estimation performance. The simulation results show that the proposed method can maintain the prediction accuracy of the intelligent virtual sensor online and shorten the training time according to the performance requirements adaptively. Under small sample conditions, the training efficiency and availability ratio of the proposed intelligent virtual sensor are improved significantly more than the neural network (BP) as well as the conventional LSTM network, improving the navigation performance in GNSS restricted environment effectively and efficiently.

Additive Manufacturing of Two-Dimensional Conductive Metal-Organic Framework with Multidimensional Hybrid Architectures for High-Performance Energy Storage.

Two-dimensional conductive metal-organic frameworks (2D CMOFs) can be regarded as high-performance electrode substances owing to their rich hierarchical porous architecture and excellent electrical conductivity. However, the sluggish kinetics behavior of electrodes within the bulk structure restricts their advances in energy storage fields. Herein, a series of graphene-based mixed-dimensional composite aerogels are achieved by incorporating the 2D M-tetrahydroxy-1,4-quinone (M-THQ) (M = Cu, Cu/Co, or Cu/Ni) into CNTs@rGO aerogel electrodes using a 3D-printing direct ink writing (DIW) technique. Benefiting from the high capacity of M-THQ and abundant porosity of the 3D-printed microlattice electrodes, an excellent capacitive performance of the M-THQ@CNTs@rGO cathodes is achieved based on the fast electron/ion transport. Furthermore, the 3D-printed lithium-ion hybrid supercapacitor (LIHCs) device assembled with Cu/Co-THQ@CNTs@rGO cathode and C60@VNNWs@rGO anode delivers a remarkable electrochemical performance. More importantly, this work manifests the practicability of printing 2D CMOFs electrodes, which provides a substantial research basis for 3D printing energy storage.

Parent-Child Cohesion and College Students' Positive/Negative Affect: The Moderating Roles of Sympathetic Nervous System Activity and Parent-Child Separation Experience.

Parent-child separation caused by parental migration could have adverse effects on individuals' emotional adaptation. However, research on this topic is limited in its focus on childhood or adolescence samples and solely environmental factors, and less is known about how positive environmental factors, biological factors and parent-child separation experience interact to influence emotional adaptation in emerging adulthood. The present study addressed these issues by investigating the relationships between parent-child cohesion and positive/negative affect, and examining the moderating roles of sympathetic nervous system activity (measured by skin conductance level reactivity, SCLR) and parent-child separation experience in the relationships. Data from 248 college students (Mage = 18.91 years, SD = 0.70; 32.3% males), including 158 college students with parent-child separation experience and 90 college students without parent-child separation experience. The results showed that parent-child cohesion predicted college students' positive/negative affect. Moreover, the moderating role of SCLR on the relationship between father-child cohesion and negative affect varied with parent-child separation experience. Specifically, father-child cohesion negatively predicted negative affect when SCLR was lower for college students with parent-child separation experience, while negatively predicted negative affect when SCLR was higher for college students without parent-child separation experience. These results indicate that the interaction pattern of Biological × Environmental predicting college students' positive/negative affect varies across parent-child separation status in childhood or adolescence.

Copper Hexacyanoferrate Solid-State Electrolyte Protection Layer on Zn Metal Anode for High-Performance Aqueous Zinc-Ion Batteries.

Zinc (Zn) metal possesses broad prospects as an anode for aqueous zinc-ion batteries (AZIBs) due to its considerable theoretical capacity of 820 mAh g-1 . However, the Zn anode suffers from dendrite growth and side reactions during Zn stripping/plating. Herein, a Prussian blue analog of copper hexacyanoferrate (CuHCF) with a 3D open structure and rich polar groups (CN) is coated on Zn foil as a solid-state electrolyte (SSE) protection layer to protect the Zn anode. The CuHCF protection layer possesses low activation energy of 26.49 kJ mol-1 , the high ionic conductivity of 7.6 mS cm-1 , and a large Zn2+ transference number of 0.74. Hence, the Zn@CuHCF||Zn@CuHCF symmetric cell delivers high cycling stability over 1800 h at 5 mA cm-2 , an excellent depth of discharge of 51.3%, and the accumulative discharge capacity over 3000 mAh cm-2 . In addition, the Zn//Ti@CuHCF asymmetric cell achieves the coulombic efficiency (CE) of 99.87% after 2000 cycles. More importantly, the Zn@CuHCF//V2 O5 full cell presents outstanding capacity retention of 87.6% at 10 A g-1 after 3000 cycles. This work develops a type of material to form an artificial protection layer for high-performance AZIBs.

CoQ10 enhances the efficacy of airway basal stem cell transplantation on bleomycin-induced idiopathic pulmonary fibrosis in mice.

BACKGROUND: Recent studies have demonstrated that airway basal stem cells (BCs) transplantation can ameliorate bleomycin-induced idiopathic pulmonary fibrosis (IPF) through lung regeneration promotion. However, BCs under oxidative stress in the alveolar microenvironment are poor in survival, causing unsatisfied efficacy of BCs transplantation. In this study, we investigated whether Coenzyme Q10(CoQ10) counteracts oxidative stress in the alveolar microenvironment, thus improved the efficacy of BCs transplantation for IPF treatment. METHODS: The protective effects of CoQ10 on H2O2-induced BCs apoptosis and cytoplasmic reactive oxygen species (ROS) level were tested by flow cytometry in vitro. The therapeutic effects of BCs combined with CoQ10 were compared to a single BCs transplantation protocol in IPF treatment after 2 weeks and were evaluated by parameters including changes of body weight and survival rate, as well as various levels of pulmonary inflammation, α-SMA expression and hydroxyproline (HYP) in IPF mouse lung tissues. RESULTS: CoQ10 preincubation with BCs (10 mM, 24 h) significantly reduced the late apoptosis of BCs and the number of oxidative stressful BCs as a result of H2O2 stimulation (1 mM, 6 h) in vitro. IPF mouse model was constructed through bleomycin (5 mg/kg) intratracheal instillation. Bleomycin-induced IPF mice showed weight loss continuously and mortality increased progressively during modeling. Serious pulmonary inflammatory cell infiltration, collagen fiber proliferation, and collagen protein deposition were observed in lung tissues of IPF mice. Though BCs transplantation alone improved indicators above in bleomycin-induced IPF mice to some extent, the combination with CoQ10 improved the transplantation efficacy and obtained better therapeutic effects. CONCLUSION: CoQ10 blocked H2O2-induced apoptosis of BCs and ROS production in vitro, and enhanced the efficacy of BCs transplantation against bleomycin-induced IPF in mice.

Effects of less invasive surfactant administration versus intubation-surfactant-extubation on bronchopulmonary dysplasia in preterm infants with respiratory distress syndrome: a single-center, retrospective study from China.

BACKGROUND: This study evaluated the effects of less invasive surfactant administration (LISA) and intubation-surfactant-extubation (InSurE) on bronchopulmonary dysplasia (BPD) in preterm infants with respiratory distress syndrome (RDS). METHODS: Neonates with respiratory distress syndrome requiring surfactant, with gestational age < 32 weeks and birth weight < 1500 g admitted to our neonatal intensive care unit from January 2018 to December 2019, were retrospectively analyzed. LISA and InSurE were used independently. The incidence of BPD at 36 weeks postmenstrual age, pre-discharge mortality, and need for mechanical ventilation (MV) within 72 h of birth were compared between LISA and InSurE group. Secondary outcomes including necrotizing enterocolitis requiring surgery, retinopathy of prematurity ≥ stage 3, patent ductus arteriosus requiring medical therapy or surgery, and length of hospitalization were analyzed. RESULTS: Among the 148 included neonates, there were 46 and 102 infants in LISA group and InSurE group, respectively. There were no significant differences in BPD incidence, the severity of BPD at 36 weeks postmenstrual age, and the rate of MV within the first 72 h after birth between the two groups (P > 0.05, respectively). The incidences of necrotizing enterocolitis requiring surgery, retinopathy of prematurity ≥ stage 3, patent ductus arteriosus requiring medical therapy or surgery, and length of hospitalization did not differ significantly between the two groups (P > 0.05, respectively). CONCLUSIONS: For surfactant administration among preterm infants with respiratory distress syndrome, LISA did not decrease bronchopulmonary dysplasia and severity of BPD at 36 weeks postmenstrual age. The benefits of LISA would require further evaluations.

Path-Guided Hierarchical Surface Relief Gratings on Azo-Films Induced by Polarized Light Illumination through Surface-Wrinkling Phase Mask.

Surface relief gratings (SRGs) with hierarchical microstructures are highly needed owing to their diverse applications in various fields. Here, we introduce surface-wrinkling templates as novel nonlithographic phase masks to direct the generation of hierarchical well-prescribed SRGs on nonconformally contacted azo-films by a simple single-beam illumination. The light-induced SRGs have controlled microstructures including single/double/triple wavelengths and single/double orientations as well as their organizations. These microstructures can be well tailored by the wavelength of the surface-wrinkling phase masks and the polarization direction of incident light relative to the wrinkling patterns in the phase masks. Interestingly, we find that the larger wavelength is induced prior to the smaller ones, offering another new strategy to tailor the microstructures of SRGs through simple manipulation of the illumination duration. In particular, path-guided SRGs with unprecedented well-organized hierarchical microstructures have been available in the case of controlled moving of the light illumination through the surface-wrinkling phase mask. As demonstrated, the obtained hierarchical SRGs with the capability of multiple optical inscription/erasure have great application potentials in fields such as confidential information (or pattern) records and encryption/decryption.

The longitudinal associations among perceived discrimination, social initiative, and depressive symptoms in Chinese rural left-behind adolescents.

INTRODUCTION: Perceived discrimination is a significant stressor in the lives of Chinese rural left-behind adolescents. Although some research has examined the effects of perceived discrimination on left-behind adolescents' psychosocial functioning, the majority of existing research is cross-sectional, which limits the understanding of the underlying mechanism of these effects. The current study used a longitudinal design to explore how perceived discrimination is associated with psychosocial functioning (i.e., depressive symptoms and social initiative) over time in Chinese rural left-behind adolescents. METHODS: A total of 1011 rural left-behind adolescents (54% boys) were involved in an ongoing longitudinal study. At Time 1 (Mage = 12.93, SD = 0.86), adolescents completed measures of perceived discrimination, depressive symptoms, and social initiative. At Time 2 (one year later), adolescents again reported on their depressive symptoms and social initiative. RESULTS: Perceived discrimination was concurrently and longitudinally associated with left-behind adolescents' depressive symptoms and social initiative. The effect of perceived discrimination on depressive symptoms was partially mediated by social initiative, while the effect of perceived discrimination on social initiative was fully mediated by depressive symptoms. The associations applied equally to adolescents with two migrant parents and adolescents with only a migrant father. CONCLUSIONS: These findings suggest the harmful impact of perceived discrimination on rural left-behind adolescents' social initiative and depressive symptoms and underscore the importance of eliminating discrimination in the rural left-behind adolescents' intervention program.

Longitudinal relations between future planning and adolescents' academic achievement in China.

INTRODUCTION: Planning for the future is important for adolescents' development and academic adaptation. Most prior research has focused primarily on the effects of future planning on adolescents' academic achievement, and there is a dearth of literature examining the effects of adolescents' academic achievement on their future planning. The current study examined the longitudinal reciprocal relations between adolescents' future planning and academic achievement in China. METHODS: The study sample consisted of 775 Chinese junior high school students (391 boys, 384 girls; Mage = 13.38 years, SD = 0.89). Future planning and academic achievement were measured at three time points that were equally spaced by a 6-month lag. Path analyses with cross-lagged effects were used to examine the longitudinal reciprocal relations between adolescents' future planning and academic achievement. RESULTS: The associations between future educational planning and academic achievement were reciprocal. Future occupational commitment predicted adolescents' academic achievement, and academic achievement predicted adolescents' affects concerning future occupation. However, there was no significant association between future occupational exploration and academic achievement. Moreover, these patterns of longitudinal relations applied equally to boys and girls, and younger and older adolescents. CONCLUSIONS: The reciprocal relations between future planning processes and academic achievement differed across domains (e.g., educational and occupational domains). These findings suggest that future planning may be a protective factor for improving adolescents' academic achievement, and high academic achievement may also be beneficial for Chinese adolescents' future planning.

Latent Profile Analysis of Left-behind Adolescents' Psychosocial Adaptation in Rural China.

Parental absence, a consequence of parents' rural-to-urban migration, exerts negative influences on their left-behind adolescents in rural China. Existing studies are limited by their focus on the isolated developmental outcomes of left-behind adolescents and by a dearth of work focused on naturally occurring patterns of their developmental outcomes. The present study used a person-centered approach to identify adolescents' adaptation profiles based on internalizing indicators (i.e., depressive symptoms, loneliness, subjective happiness, life satisfaction), externalizing indicators (i.e., rule-breaking behavior, aggressive behavior, prosocial behavior) and academic achievement and to relate these profiles to left-behind status, characteristics of parent-adolescent separation and gender. The study included 2102 adolescents (Mage = 13.48 ± 1.10 years, 46.8% girls) in junior high schools in rural China. A latent profile analysis identified 3 profiles: an adequate adaptation profile, an internalizing problem profile and an externalizing problem profile. These profiles were linked to left-behind status, to characteristics of parent-adolescent separation (i.e., separation duration, interval of long-distance communication and face-to-face communication) and to gender. These findings provide significant implications for future research and the development of interventions.

Design of retinal-projection-based near-eye display with contact lens.

We propose a design of a retinal-projection-based near-eye display for achieving ultra-large field of view, vision correction, and occlusion. Our solution is highlighted by a contact lens combo, a transparent organic light-emitting diode panel, and a twisted nematic liquid crystal panel. Its design rules are set forth in detail, followed by the results and discussion regarding the field of view, angular resolution, modulation transfer function, contrast ratio, distortion, and simulated imaging.

Determinative Surface-Wrinkling Microstructures on Polypyrrole Films by Laser Writing.

We report a simple and efficient laser-writing strategy to fabricate hierarchical nested wrinkling microstructures on conductive polypyrrole (PPy) films, which enables us to develop advanced functional surfaces with diverse applications. The present strategy adopts the photothermal effect of PPy films to mimick the formation of hierarchical nested wrinkles observed in nature and design controlled microscale wrinkling patterns. Here, the PPy film is grown on a poly(dimethylsiloxane) (PDMS) substrate via oxidation polymerization of pyrrole in an acidic solution, accompanied by in situ self-wrinkling with wavelengths of two different scales (i.e., λ1 and λ2). Subsequent laser exposure of the PPy/PDMS bilayer induces a new surface wrinkling with a larger wavelength (i.e., λ3). Owing to the retention of the initial λ1 wrinkles, we obtain hierarchical nested wrinkles with the smaller λ1 wrinkles nested in the larger λ3 ones. Importantly, we realize the large-scale path-determinative fabrication of complex oriented wrinkling microstructures by controlling the relative motion between the bilayer and the laser. Combined with the induced changes in surface color, surface-wrinkling microstructures, and conductivity in the PPy films, the laser-writing strategy can find broad applications, for example, in modulation of surface wetting properties and fabrication of microcircuits, as demonstrated in this work.

Left-behind adolescents' hopes and fears for the future in rural China.

The present study examined the contents of future hopes and fears among Chinese adolescents left behind by one or both of their rural-to-urban migrant parents compared to those from rural and urban nonmigrant families. Data from 1083 participants (50.2% boys; Mage = 13.50 years; SD = 1.06) indicated that adolescents reported future hopes and fears in a variety of life domains, including future education, academics, occupation, marriage and family, parents' and relatives' wellbeing, interpersonal relationships, leisure activities, wealth and self-related issues. Adolescents from both-parent-migrant families reported more hopes and fears for interpersonal relationships and more fears for parents' and relatives' wellbeing than other adolescents. Moreover, boys from migrant families reported more hopes for occupation and fewer hopes for interpersonal relationships than girls from migrant families, whereas no gender differences were found among adolescents from nonmigrant families. These results suggest the important roles of parental migration in adolescents' future thinking.

Constructing Ultrahigh-Capacity Zinc-Nickel-Cobalt Oxide@Ni(OH)2 Core-Shell Nanowire Arrays for High-Performance Coaxial Fiber-Shaped Asymmetric Supercapacitors.

Increased efforts have recently been devoted to developing high-energy-density flexible supercapacitors for their practical applications in portable and wearable electronics. Although high operating voltages have been achieved in fiber-shaped asymmetric supercapacitors (FASCs), low specific capacitance still restricts the further enhancement of their energy density. This article specifies a facile and cost-effective method to directly grow three-dimensionally well-aligned zinc-nickel-cobalt oxide (ZNCO)@Ni(OH)2 nanowire arrays (NWAs) on a carbon nanotube fiber (CNTF) with an ultrahigh specific capacitance of 2847.5 F/cm3 (10.678 F/cm2) at a current density of 1 mA/cm2, These levels are approximately five times higher than those of ZNCO NWAs/CNTF electrodes (2.10 F/cm2) and four times higher than Ni(OH)2/CNTF electrodes (2.55 F/cm2). Benefiting from their unique features, we successfully fabricated a prototype coaxial FASC (CFASC) with a maximum operating voltage of 1.6 V, which was assembled by adopting ZNCO@Ni(OH)2 NWAs/CNTF as the core electrode and a thin layer of carbon coated vanadium nitride (VN@C) NWAs on a carbon nanotube strip (CNTS) as the outer electrode with KOH poly(vinyl alcohol) (PVA) as the gel electrolyte. A high specific capacitance of 94.67 F/cm3 (573.75 mF/cm2) and an exceptional energy density of 33.66 mWh/cm3 (204.02 µWh/cm2) were achieved for our CFASC device, which represent the highest levels of fiber-shaped supercapacitors to date. More importantly, the fiber-shaped ZnO-based photodetector is powered by the integrated CFASC, and it demonstrates excellent sensitivity in detecting UV light. Thus, this work paves the way to the construction of ultrahigh-capacity electrode materials for next-generation wearable energy-storage devices.

Wrapping Aligned Carbon Nanotube Composite Sheets around Vanadium Nitride Nanowire Arrays for Asymmetric Coaxial Fiber-Shaped Supercapacitors with Ultrahigh Energy Density.

The emergence of fiber-shaped supercapacitors (FSSs) has led to a revolution in portable and wearable electronic devices. However, obtaining high energy density FSSs for practical applications is still a key challenge. This article exhibits a facile and effective approach to directly grow well-aligned three-dimensional vanadium nitride (VN) nanowire arrays (NWAs) on carbon nanotube (CNT) fiber with an ultrahigh specific capacitance of 715 mF/cm2 in a three-electrode system. Benefiting from their intriguing structural features, we successfully fabricated a prototype asymmetric coaxial FSS (ACFSS) with a maximum operating voltage of 1.8 V. From core to shell, this ACFSS consists of a CNT fiber core coated with VN@C NWAs as the negative electrode, Na2SO4 poly(vinyl alcohol) (PVA) as the solid electrolyte, and MnO2/conducting polymer/CNT sheets as the positive electrode. The novel coaxial architecture not only fully enables utilization of the effective surface area and decreases the contact resistance between the two electrodes but also, more importantly, provides a short pathway for the ultrafast transport of axial electrons and ions. The electrochemical results show that the optimized ACFSS exhibits a remarkable specific capacitance of 213.5 mF/cm2 and an exceptional energy density of 96.07 µWh/cm2, the highest areal capacitance and areal energy density yet reported in FSSs. Furthermore, the device possesses excellent flexibility in that its capacitance retention reaches 96.8% after bending 5000 times, which further allows it to be woven into flexible electronic clothes with conventional weaving techniques. Therefore, the asymmetric coaxial architectural design allows new opportunities to fabricate high-performance flexible FSSs for future portable and wearable electronic devices.