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In only a few decades, lithium-ion batteries have revolutionized technologies, enabling the proliferation of portable devices and electric vehicles1, with substantial benefits for society. However, the rapid growth in technology has highlighted the ethical and environmental challenges of mining lithium, cobalt and other mineral ore resources, and the issues associated with the safe usage and non-hazardous disposal of batteries2. Only a small fraction of lithium-ion batteries are recycled, further exacerbating global material supply of strategic elements3-5. A potential alternative is to use organic-based redox-active materials6-8 to develop rechargeable batteries that originate from ethically sourced, sustainable materials and enable on-demand deconstruction and reconstruction. Making such batteries is challenging because the active materials must be stable during operation but degradable at end of life. Further, the degradation products should be either environmentally benign or recyclable for reconstruction into a new battery. Here we demonstrate a metal-free, polypeptide-based battery, in which viologens and nitroxide radicals are incorporated as redox-active groups along polypeptide backbones to function as anode and cathode materials, respectively. These redox-active polypeptides perform as active materials that are stable during battery operation and subsequently degrade on demand in acidic conditions to generate amino acids, other building blocks and degradation products. Such a polypeptide-based battery is a first step to addressing the need for alternative chemistries for green and sustainable batteries in a future circular economy.
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Fontes de Energia Elétrica , Eletroquímica , Peptídeos/química , Animais , Bovinos , Linhagem Celular , Sobrevivência Celular , Óxidos N-Cíclicos/química , Camundongos , Osteoblastos/citologia , Oxirredução , Peptídeos/síntese química , Desenvolvimento Sustentável , Viologênios/químicaRESUMO
Polyvinyl polymers bearing pendant hole transport functionalities have been extensively explored for solution-processed hole transport layer (HTL) technologies, yet there are only rare examples of high anisotropic packing of the HT moieties of these polymers into substrate-parallel orientations within HTL films. For small molecules, substrate-parallel alignment of HT moieties is a well-established approach to improve overall device performance. To address the longstanding challenge of extension from vapor-deposited small molecules to solution-processable polymer systems, a fundamental chemistry tactic is reported here, involving the positioning of HT side chains within macromolecular frameworks by the construction of HT polymers having bottlebrush topologies. Applying state-of-the-art polymer synthetic techniques, various functional subunits, including triphenylamine (TPA) for hole transport and adhesion to the substrate, and perfluoro alkyl-substituted benzyloxy styrene for migration to the air interface, were organized with exquisite control over the composition and placement throughout the bottlebrush topology. Upon assembling the HT bottlebrush (HTB) polymers into monolayered HTL films on various substrates through spin-casting and thermal annealing, the backbones of HTBs were vertically aligned while the grafts with pendant TPAs were extended parallel to the substrate. The overall design realized high TPA π-stacking along the out-of-plane direction of the substrate in the HTLs, which doubled the efficiency of organic light-emitting diodes compared with linear poly(vinyl triphenylamine)s.
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It is known that grafting one polymer onto another polymer backbone is a powerful strategy capable of combining dual benefits from each parent polymer. Thus amphiphilic graft copolymer precursors (poly(vinylidene difluoride)-graft-poly(tert-butylacrylate) (PVDF-g-PtBA)) have been developed via atom transfer radical polymerization, and demonstrated its outstanding properties as a promising binder for high-performance lithium-ion battery (LIB) by using in situ pyrolytic transformation of PtBA to poly(acrylic acid) segments. In addition to its superior mechanical properties and accommodation capability of volume expansion, the Si anode with PVDF-g-PtBA exhibits the excellent charge and discharge capacities of 2672 and 2958 mAh g(-1) with the capacity retention of 84% after 50 cycles. More meaningfully, the graft copolymer binder shows good operating characteristics in both LiN0.5 M1.5 O4 cathode and neural graphite anode, respectively. By containing such diverse features, a graft copolymer-loaded LiN0.5 M1.5 O4 /Si-NG full cell has been successfully achieved, which delivers energy density as high as 546 Wh kg(-1) with cycle retention of ≈70% after 50 cycles (1 C). For the first time, this work sheds new light on the unique nature of the graft copolymer binders in LIB application, which will provide a practical solution for volume expansion and low efficiency problems, leading to a high-energy-density lithium-ion chemistry.
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To expand the single-dose duration over which noninvasive clinical and preclinical cancer imaging can be conducted with high sensitivity, and well-defined spatial and temporal resolutions, a facile strategy to prepare ultrasmall nanoparticulate X-ray contrast media (nano-XRCM) as dual-modality imaging agents for positron emission tomography (PET) and computed tomography (CT) has been established. Synthesized from controlled copolymerization of triiodobenzoyl ethyl acrylate and oligo(ethylene oxide) acrylate monomers, the amphiphilic statistical iodocopolymers (ICPs) could directly dissolve in water to afford thermodynamically stable solutions with high aqueous iodine concentrations (>140 mg iodine/mL water) and comparable viscosities to conventional small molecule XRCM. The formation of ultrasmall iodinated nanoparticles with hydrodynamic diameters of ca. 10 nm in water was confirmed by dynamic and static light scattering techniques. In a breast cancer mouse model, in vivo biodistribution studies revealed that the 64Cu-chelator-functionalized iodinated nano-XRCM exhibited extended blood residency and higher tumor accumulation compared to typical small molecule imaging agents. PET/CT imaging of tumor over 3 days showed good correlation between PET and CT signals, while CT imaging allowed continuous observation of tumor retention even after 10 days post-injection, enabling longitudinal monitoring of tumor retention for imaging or potentially therapeutic effect after a single administration of nano-XRCM.
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This study aimed to investigate the association between galectin-3 concentration and estimated glomerular filtration rate (eGFR) in patients with type 2 diabetes mellitus (T2DM) with and without albuminuria. In this cross-sectional study, we examined 334 patients with T2DM. The eGFR was calculated using a creatinine-based formula (eGFRcrea) and a combined creatinine-cystatin C equation (eGFRcrea-cyst). The participants were categorized into two groups based on the urinary albumin-to-creatinine ratio (UACR): patients without albuminuria (UACR < 30 mg/g) and those with albuminuria (UACR ≥ 30 mg/g). Greater concentrations of plasma galectin-3 were associated with lower eGFRcrea-cyst and eGFRcrea levels in patients with and without albuminuria. Plasma galectin-3 concentrations were negatively correlated with eGFRcrea-cyst in patients with normoalbuminuria and albuminuria (γ = - 0.405, P < 0.001; γ = - 0.525, P < 0.001, respectively). Galectin-3 concentrations were significantly associated with eGFRcrea-cyst after adjusting for sex, age, and other confounding factors, including UACR as a categorical or continuous variable in multiple regression analyses (ß = - 0.294, 95% CI - 70.804 to - 41.768, P < 0.001; ß = - 0.265, 95% CI - 65.192 to - 36.550, P < 0.001, respectively). Likewise, when eGFRcrea-cyst was treated in place of eGFRcrea, this result was replicated in the correlation and regression analyses. Galectin-3 concentration was negatively associated with eGFR in patients with T2DM, independent of albuminuria status.
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Cistos , Diabetes Mellitus Tipo 2 , Albuminas , Albuminúria , Creatinina , Estudos Transversais , Cistatina C , Diabetes Mellitus Tipo 2/complicações , Galectina 3 , Taxa de Filtração Glomerular , HumanosRESUMO
The development of hemostatic technologies that suit a diverse range of emergency scenarios is a critical initiative, and there is an increasing interest in the development of absorbable dressings that can be left in the injury site and degrade to reduce the duration of interventional procedures. In the current study, ß-cyclodextrin polyester (CDPE) hydrogels serve as sacrificial macroporous carriers, capable of degradation under physiological conditions. The CDPE template enables the assembly of imprinted chitosan honeycomb-like monolithic mats, containing highly entangled nanofibers with diameters of 9.2 ± 3.7 nm, thereby achieving an increase in the surface area of chitosan to improve hemostatic efficiency. In vivo, chitosan-loaded cyclodextrin (CDPE-Cs) hydrogels yield significantly lower amounts of blood loss and shorter times to hemostasis compared with commercially available absorbable hemostatic dressings, and are highly biocompatible. The designed hydrogels demonstrate promising hemostatic efficiency, as a physiologically-benign approach to mitigating blood loss in tissue-injury scenarios.
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Bandagens , Hemorragia/terapia , Hemostáticos/química , Hidrogéis/química , Animais , Materiais Biocompatíveis/química , Quitosana/química , Ciclodextrinas/química , Modelos Animais de Doenças , Feminino , Hemorragia/etiologia , Técnicas Hemostáticas , Humanos , Masculino , Nanofibras/química , Coelhos , Ratos , Ratos Sprague-Dawley , Sus scrofa , Resultado do TratamentoRESUMO
OBJECTIVES: This study investigated the effect of social skills training (SST) on facial emotion recognition and discrimination in children with attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). METHODS: Twenty-three children aged 7 to 10 years participated in our SST. They included 15 children diagnosed with ADHD and 8 with ASD. The participants' parents completed the Korean version of the Child Behavior Checklist (K-CBCL), the ADHD Rating Scale, and Conner's Scale at baseline and post-treatment. The participants completed the Korean Wechsler Intelligence Scale for Children-IV (K-WISC-IV) and the Advanced Test of Attention at baseline and the Penn Emotion Recognition and Discrimination Task at baseline and post-treatment. RESULTS: No significant changes in facial emotion recognition and discrimination occurred in either group before and after SST. However, when controlling for the processing speed of K-WISC and the social subscale of K-CBCL, the ADHD group showed more improvement in total (p=0.049), female (p=0.039), sad (p=0.002), mild (p=0.015), female extreme (p=0.005), male mild (p=0.038), and Caucasian (p=0.004) facial expressions than did the ASD group. CONCLUSION: SST improved facial expression recognition for children with ADHD more effectively than it did for children with ASD, in whom additional training to help emotion recognition and discrimination is needed.
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Camptothecin (CPT) is a promising anticancer drug, yet its therapeutic potential has been limited by poor water solubility and facile hydrolysis of the lactone form into an inactive carboxylate form at neutral pH. In this work, a fundamental synthetic methodology was advanced to allow for the preparation of well-defined functional polyphosphoramidate (PPA)-based block copolymers that coassembled with CPT into nanoparticles, which underwent coincident acid-triggered polymer backbone degradation, nanoparticle disassembly, and CPT release. Encapsulation of CPT by the PPA polymer inhibited premature hydrolysis of CPT at pH 7.4 and enabled accelerated CPT release at pH 5.0 (ca. 4× faster than at pH 7.4). Two degradable oxazaphospholidine monomers, with one carrying an alkyne group, were synthesized to access well-defined block PPAs (dispersity, D<1.2) via sequential organobase-catalyzed ring-opening polymerizations (ROP). The resulting amphiphilic block copolymers (PEOMP-b-PBYOMP) were physically loaded with CPT to achieve well-dispersed nanotherapeutics, which allowed the aqueous suspension of CPT at concentrations up to 3.2 mg/mL, significantly exceeding the aqueous solubility of the drug (<2.0 µg/mL at 37 °C). Cytotoxicity studies revealed enhanced efficacy of the CPT-loaded nanoparticles over free CPT in cancer cells and similar toxicity in normal cells.
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We fabricate nanotubular ZnO with wall thickness of 45, 92, 123 nm using nanoporous gold (np-Au) with ligament diameter at necks of 1.43 µm as sacrificial template. Through micro-tensile and micro-compressive testing of nanotubular ZnO structures, we find that the exponent m in [Formula: see text], where [Formula: see text] is the relative strength and [Formula: see text] is the relative density, for tension is 1.09 and for compression is 0.63. Both exponents are lower than the value of 1.5 in the Gibson-Ashby model that describes the relation between relative strength and relative density where the strength of constituent material is independent of external size, which indicates that strength of constituent ZnO increases as wall thickness decreases. We find, based on hole-nanoindentation and glazing incidence X-ray diffraction, that this wall-thickness-dependent strength of nanotubular ZnO is not caused by strengthening of constituent ZnO by size reduction at the nanoscale. Finite element analysis suggests that the wall-thickness-dependent strength of nanotubular ZnO originates from nanotubular structures formed on ligaments of np-Au.
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Molecular structures of polysaccharide binders determining mechanical properties were correlated to electrochemical performances of silicon anodes for lithium-ion batteries. Glycosidic linkages (α and ß) and side chains (-COOH and -OH) were selected and proven as the major factors of the molecular structures. Three different single-component polysaccharides were compared: pectin for α-linkages versus carboxylic methyl cellulose (CMC) for ß-linkages from the linkage's standpoint, and pectin as a COOH-containing polymer and amylose as its non-COOH counterpart from the side chain's standpoint. Pectin was remarkably superior to CMC and amylose in cyclability and rate capability of battery cells based on silicon anodes. The pectin binder allowed volume expansion of silicon electrodes with keeping high porosity during lithiation due to the elastic nature caused by the chair-to-boat conformation in α-linkages of its backbone. Physical integrity of pectin-based electrodes was not challenged during repeated lithiation/delithiation cycles without crack development that was observed in rigid CMC-based electrodes. Covalent bonds formed between carboxylic side chains of pectin and silicon surface oxide prevented active silicon mass from being detached away from electric pathways. However, hydrogen bonds between hydroxyl side chains of amylose and silicon surface oxide were not strong enough to keep the silicon mass electrochemically active after cyclability tests.
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Técnicas Eletroquímicas , Lítio/química , Polissacarídeos/química , Silício/química , Configuração de CarboidratosRESUMO
Silicon anode materials have been developed to achieve high capacity lithium ion batteries for operating smart phones and driving electric vehicles for longer time. Serious volume expansion induced by lithiation, which is the main drawback of silicon, has been challenged by multi-faceted approaches. Mechanically rigid and stiff polymers (e.g. alginate and carboxymethyl cellulose) were considered as the good choices of binders for silicon because they grab silicon particles in a tight and rigid way so that pulverization and then break-away of the active mass from electric pathways are suppressed. Contrary to the public wisdom, in this work, we demonstrate that electrochemical performances are secured better by letting silicon electrodes breathe in and out lithium ions with volume change rather than by fixing their dimensions. The breathing electrodes were achieved by using a polysaccharide (pullulan), the conformation of which is modulated from chair to boat during elongation. The conformational transition of pullulan was originated from its α glycosidic linkages while the conventional rigid polysaccharide binders have ß linkages.
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Módulo de Elasticidade/fisiologia , Fontes de Energia Elétrica , Eletrodos , Lítio/química , Silício/química , Condutividade Elétrica , Técnicas Eletroquímicas , Glucanos/química , Dureza/fisiologia , Conformação Molecular , NanotecnologiaRESUMO
Hydrophobic sponge structure-based triboelectric nanogenerators using an inverse opal structured film for sustainable energy harvesting over a wide range of humid atmosphere have been successfully demonstrated. The output voltage and current density reach a record value of 130 V and 0.10 mA cm(-2) , respectively, giving over 10-fold power enhancement, compared with the flat film-based triboelectric nanogenerator.
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Fontes de Energia Elétrica , Interações Hidrofóbicas e Hidrofílicas , Fenômenos Mecânicos , Nanotecnologia/instrumentação , Alumínio/química , Dimetilpolisiloxanos/química , Condutividade Elétrica , Eletricidade EstáticaRESUMO
OBJECTIVE: To investigate the prevalence of dementia and its correlates among people with poor socioeconomic status, poor social support systems, and poor performance on the Korean version of the Mini-Mental Status Exam (MMSE-KC). METHODS: We used 2006-2009 data of the National Early Dementia Detection Program (NEDDP) conducted on Jeju Island. This program included all residents >65 years old who were receiving financial assistance. We examined those who performed poorly (standard deviation from the norm of <-1.5) on the MMSE-KC administered as part of the NEDDP, using age-, gender-, and education-adjusted norms for Korean elders. A total of 1708 people were included in this category. RESULTS: The prevalence of dementia in this group was 20.5%. Multivariate logistic regression analysis revealed that the following factors were statistically significantly associated with dementia: age of 80 or older, no education, nursing home residence, and depression. CONCLUSION: The prevalence of dementia is very high among those with lower MMSE-KC scores, and significant correlates include older age, no education, living in a nursing home, and depression. Enhancing lifetime education to improve individuals' cognitive reserves by providing intellectually challenging activities, encouraging living at home rather than in a nursing home, and preventing and treating depression in its early phase could reduce the prevalence of dementia in this population.
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Tardive dyskinesia is characterized by choreiform movements, or rhythmic abnormal involuntary movements of the face, mouth, tongue, trunk, and limbs. It is frequently associated with the use of neuroleptic medications. The choreiform movements are irreversible in some patients, even after the drug is withdrawn. Although no reliable treatment for tardive dyskinesia exists, atypical antipsychotics are associated with a significantly lower incidence of tardive dyskinesia than typical antipsychotics. Moreover, recent reports suggest that atypical antipsychotics may have a beneficial effect on tardive dyskinesia remission. Until recently, evidence for the effectiveness of aripiprazole on tardive dyskinesia has been mixed. Aripiprazole has a unique mechanism of action and has various effects in tardive dyskinesia. The drug acts as a partial D(2) receptor agonist that can stabilize D(2) up-regulation, and as a partial 5-HT(1A) receptor agonist and a 5-HT(2A) receptor antagonist, and can increase the release of dopamine in the striatum.