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1.
J Am Chem Soc ; 145(40): 21807-21816, 2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37770040

RESUMO

Perovskite oxides ABO3 continue to be a major focus in materials science. Of particular interest is the interplay between A and B cations as exemplified by intersite charge transfer (ICT), which causes novel phenomena including negative thermal expansion and metal-insulator transition. However, the ICT properties were achieved and optimized by cationic substitution or ordering. Here we demonstrate an anionic approach to induce ICT using an oxyhydride perovskite, EuVO2H, which has alternating layers of EuH and VO2. A bulk EuVO2H behaves as a ferromagnetic insulator with a relatively high transition temperature (TC) of 10 K. However, the application of external pressure to the EuIIVIIIO2H bulk or compressive strain from the substrate in the thin films induces ICT from the EuIIH layer to the VIIIO2 layer due to the extended empty V dxy orbital. The ICT phenomenon causes the VO2 layer to become conductive, leading to an increase in TC that is dependent on the number of carriers in the dxy orbitals (up to a factor of 4 for 10 nm thin films). In addition, a large perpendicular magnetic anisotropy appears with the ICT for the films of <100 nm, which is unprecedented in materials with orbital-free Eu2+, opening new perspectives for applications. The present results provide opportunities for the acquisition of novel functions by alternating transition metal/rare earth layers with heteroanions.

2.
Phys Rev Lett ; 130(16): 166001, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37154635

RESUMO

Recently, a superconducting (SC) transition from low-field (LF) to high-field (HF) SC states was reported in CeRh_{2}As_{2}, indicating the existence of multiple SC states. It has been theoretically noted that the existence of two Ce sites in the unit cell, the so-called sublattice degrees of freedom owing to the local inversion symmetry breaking at the Ce sites, can lead to the appearance of multiple SC phases even under an interaction inducing spin-singlet superconductivity. CeRh_{2}As_{2} is considered as the first example of multiple SC phases owing to this sublattice degree of freedom. However, microscopic information about the SC states has not yet been reported. In this study, we measured the SC spin susceptibility at two crystallographically inequivalent As sites using nuclear magnetic resonance for various magnetic fields. Our experimental results strongly indicate a spin-singlet state in both SC phases. In addition, the antiferromagnetic phase, which appears within the SC phase, only coexists with the LF SC phase; there is no sign of magnetic ordering in the HF SC phase. The present Letter reveals unique SC properties originating from the locally noncentrosymmetric characteristics.

3.
Phys Rev Lett ; 128(5): 057002, 2022 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-35179930

RESUMO

Spatial inversion symmetry in crystal structures is closely related to the superconducting (SC) and magnetic properties of materials. Recently, several theoretical proposals that predict various interesting phenomena caused by the breaking of the local inversion symmetry have been presented. However, experimental validation has not yet progressed owing to the lack of model materials. Here we present evidence for antiferromagnetic (AFM) order in CeRh_{2}As_{2} (SC transition temperature T_{SC}∼0.37 K), wherein the Ce site breaks the local inversion symmetry. The evidence is based on the observation of different extents of broadening of the nuclear quadrupole resonance spectrum at two crystallographically inequivalent As sites. This AFM ordering breaks the inversion symmetry of this system, resulting in the activation of an odd-parity magnetic multipole. Moreover, the onset of antiferromagnetism T_{N} within an SC phase, with T_{N}

4.
Infect Immun ; 88(3)2020 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-31843965

RESUMO

Interleukin-4 (IL-4) is crucial in many helminth infections, but its role in urogenital schistosomiasis, infection with Schistosoma haematobium worms, remains poorly understood due to a historical lack of animal models. The bladder pathology of urogenital schistosomiasis is caused by immune responses to eggs deposited in the bladder wall. A range of pathology occurs, including urothelial hyperplasia and cancer, but associated mechanisms and links to IL-4 are largely unknown. We modeled urogenital schistosomiasis by injecting the bladder walls of IL-4 receptor-alpha knockout (Il4ra-/- ) and wild-type mice with S. haematobium eggs. Readouts included bladder histology and ex vivo assessments of urothelial proliferation, cell cycle, and ploidy status. We also quantified the effects of exogenous IL-4 on urothelial cell proliferation in vitro, including cell cycle status and phosphorylation patterns of major downstream regulators in the IL-4 signaling pathway. There was a significant decrease in the intensity of granulomatous responses to bladder-wall-injected S. haematobium eggs in Il4ra-/- versus wild-type mice. S. haematobium egg injection triggered significant urothelial proliferation, including evidence of urothelial hyper-diploidy and cell cycle skewing in wild-type but not Il4ra-/- mice. Urothelial exposure to IL-4 in vitro led to cell cycle polarization and increased phosphorylation of AKT. Our results show that IL-4 signaling is required for key pathogenic features of urogenital schistosomiasis and that particular aspects of this signaling pathway may exert these effects directly on the urothelium. These findings point to potential mechanisms by which urogenital schistosomiasis promotes bladder carcinogenesis.


Assuntos
Interleucina-4/imunologia , Schistosoma haematobium/imunologia , Esquistossomose Urinária , Transdução de Sinais/fisiologia , Bexiga Urinária/patologia , Animais , Modelos Animais de Doenças , Camundongos , Esquistossomose Urinária/imunologia , Esquistossomose Urinária/patologia
5.
Mol Pain ; 16: 1744806920970099, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33342372

RESUMO

The transient receptor potential cation channel subfamily V member 1 (TRPV1) receptor is an important mediator of nociception and its expression is enriched in nociceptive neurons. TRPV1 signaling has been implicated in bladder pain and is a potential analgesic target. Resiniferatoxin is the most potent known agonist of TRPV1. Acute exposure of the rat bladder to resiniferatoxin has been demonstrated to result in pain-related freezing and licking behaviors that are alleviated by virally encoded IL-4. The interleukin-4-inducing principle of Schistosoma mansoni eggs (IPSE) is a powerful inducer of IL-4 secretion, and is also known to alter host cell transcription through a nuclear localization sequence-based mechanism. We previously reported that IPSE ameliorates ifosfamide-induced bladder pain in an IL-4- and nuclear localization sequence-dependent manner. We hypothesized that pre-administration of IPSE to resiniferatoxin-challenged mice would dampen pain-related behaviors. IPSE indeed lessened resiniferatoxin-triggered freezing behaviors in mice. This was a nuclear localization sequence-dependent phenomenon, since administration of a nuclear localization sequence mutant version of IPSE abrogated IPSE's analgesic effect. In contrast, IPSE's analgesic effect did not seem IL-4-dependent, since use of anti-IL-4 antibody in mice given both IPSE and resiniferatoxin did not significantly affect freezing behaviors. RNA-Seq analysis of resiniferatoxin- and IPSE-exposed bladders revealed differential expression of TNF/NF-κb-related signaling pathway genes. In vitro testing of IPSE uptake by urothelial cells and TRPV1-expressing neuronal cells showed uptake by both cell types. Thus, IPSE's nuclear localization sequence-dependent therapeutic effects on TRPV1-mediated bladder pain may act on TRPV1-expressing neurons and/or may rely upon urothelial mechanisms.


Assuntos
Diterpenos/efeitos adversos , Proteínas do Ovo/uso terapêutico , Proteínas de Helminto/uso terapêutico , Interações Hospedeiro-Parasita/imunologia , Fatores Imunológicos/uso terapêutico , Dor/tratamento farmacológico , Parasitos/química , Bexiga Urinária/patologia , Animais , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Proteínas do Ovo/farmacologia , Endocitose/efeitos dos fármacos , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Helminto/farmacologia , Humanos , Fatores Imunológicos/farmacologia , Interleucina-4/metabolismo , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Sinais de Localização Nuclear/metabolismo , Dor/genética , Análise de Componente Principal , Transporte Proteico/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo , Bexiga Urinária/efeitos dos fármacos , Urotélio/metabolismo
6.
Phys Rev Lett ; 121(15): 157004, 2018 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-30362806

RESUMO

Nuclear magnetic resonance measurements were performed on CeCu_{2}Si_{2} in the presence of a magnetic field close to the upper critical field µ_{0}H_{c2} in order to investigate its superconducting (SC) properties near pair-breaking fields. In lower fields, the Knight shift and nuclear spin-lattice relaxation rate divided by temperature 1/T_{1}T abruptly decreased below the SC transition temperature T_{c}(H), a phenomenon understood within the framework of conventional spin-singlet superconductivity. In contrast, 1/T_{1}T was enhanced just below T_{c}(H) and exhibited a broad maximum when magnetic fields close to µ_{0}H_{c2}(0) were applied parallel or perpendicular to the c axis; although the Knight shift decreased just below T_{c}(H). This enhancement of 1/T_{1}T, which was recently observed in the organic superconductor κ-(BEDT-TTF)_{2}Cu(NCS)_{2}, suggests the presence of high-density Andreev bound states in the inhomogeneous SC region, a hallmark of the Fulde-Ferrell-Larkin-Ovchinnikov phase.

7.
Phys Chem Chem Phys ; 20(33): 21262-21268, 2018 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-29952385

RESUMO

The low volatility of ionic liquids (ILs) is one of their most interesting physico-chemical properties; however, the general understanding of their evaporation dynamics under vacuum is still lagging. Here, we studied the thermodynamics of IL evaporation by employing thermogravimetry (TG) measurements under vacuum. The thermodynamic parameters of ILs, such as the evaporation onset temperatures, enthalpies, entropies, saturation vapor pressures, and boiling points were quantified by analyzing the TG data. The obtained evaporation enthalpies (110-140 kJ mol-1) were higher than those of typical molecular liquids, and the entropies (>88 J mol-1 K-1) suggested that they are exceptions of the Trouton's rule. The obtained Clausius-Clapeyron equations demonstrated that the saturation vapor pressures of ILs only depend on temperature. Further, we derived the empirical equation for estimating the upper limit temperature of the liquid phase of IL under given external pressures. Using the evaporation behaviors of referential normal alkanes and charge-transfer complex and the evaporation entropies of the ILs, the vaporized IL structure was thermodynamically modelled. The ILs were found to evaporate as ion pairs, instead of as individual ions or higher-ordered cluster structures. By comparing a series of ILs with various cations and a fixed anion, it was found that the IL evaporation dynamics under vacuum is strongly and systematically affected by their chemical structures, charge balances between the cations and the anions, molecular weights, and the higher-ordered structures including polar and non-polar regions. Our concept, measurement method, and equation can be extended to other ILs and low-volatile liquids under vacuum, and help with the design of ILs with higher thermal stabilities.

8.
Anal Chem ; 87(3): 1797-803, 2015 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-25546230

RESUMO

A high-sensitivity immunoassay system with surface plasmon field-enhanced fluorescence spectrometry (SPFS) was constructed using a plastic sensor chip and then applied to the detection of total prostate-specific antigen (total PSA) and GalNAcß1-4GlcNAc-linked prostate-specific antigen (LacdiNAc-PSA) in serum, to discriminate between prostate cancer (PC) and benign prostate hyperplasia (BPH). By using this automated SPFS immunoassay, the detection limit for total PSA in serum was as low as 0.04 pg/mL, and the dynamic range was estimated to be at least five digits. A two-step sandwich SPFS immunoassay for LacdiNAc-PSA was constructed using both the anti-PSA IgG antibody to capture PSA and Wisteria floribunda agglutinin (WFA) for the detection of LacdiNAc. The results of the LacdiNAc-PSA immunoassay with SPFS showed that the assay had a sensitivity of 20.0 pg/mL and permitted the specific distinction between PC and BPH within the PSA gray zone. These results suggested that high-sensitivity automated SPFS immunoassay systems might become a powerful tool for the diagnosis of PC and other diseases.


Assuntos
Imunoensaio/instrumentação , Lactose/análogos & derivados , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/diagnóstico , Desenho de Equipamento , Humanos , Lactose/análise , Lactose/sangue , Limite de Detecção , Masculino , Antígeno Prostático Específico/análise , Neoplasias da Próstata/sangue , Espectrometria de Fluorescência/instrumentação
9.
J Phys Ther Sci ; 27(9): 2771-4, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26504290

RESUMO

[Purpose] This study aimed to investigate the differential effects of high-intensity and low-intensity transcutaneous electrical nerve stimulation on the contralateral side on the pain threshold in healthy subjects. [Subjects and Methods] Twenty-five healthy adults, volunteers received two intensity levels (motor-level, 1.5 times the muscle motor threshold; sensory-level, sensory threshold of the common peroneal nerve), for 30 s on separate days. Pressure pain threshold was recorded on the contralateral tibialis anterior and deltoid muscle before, during, and after stimulation. [Results] Motor-level stimulation significantly increased the pressure pain threshold at both muscle sites, while effects of sensory-level stimulation on pressure pain thresholds were significant only at the deltoid site. The percent change in pressure pain thresholds at both sites was significantly higher during motor-level stimulation. [Conclusion] Motor-level stimulation, applied unilaterally to one leg, produced immediate contralateral diffuse and segmental analgesic effects. This may be of therapeutic benefit in patients for whom transcutaneous electrical nerve stimulation cannot be directly used at the painful site.

10.
Environ Health Prev Med ; 19(1): 21-9, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23868713

RESUMO

OBJECTIVES: The mechanism by which muscle weakness leads to an increased risk of death remains a subject of interest. In this context, the aim of this study is to assess the relationship between urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and muscle strength, and other risk factors contributing to poor muscle strength in older persons. METHODS: This was a cross-sectional study in which a total of 86 participants, both men and women, aged 65 years or above were screened for urinary 8-OHdG, and muscle strength as measured by handgrip strength. RESULTS: Handgrip strength was lower in participants who had history of acute or chronic disease. Urinary 8-OHdG level was negatively associated with muscle strength, and the association remained after adjusting for confounding factors. CONCLUSIONS: Urinary 8-OHdG is associated with muscle strength. These findings may be clinically relevant as there is a possibility of controlling oxidative DNA damage by healthy behaviors related to lifestyle.


Assuntos
Desoxiguanosina/análogos & derivados , Força da Mão , Força Muscular , Estresse Oxidativo , 8-Hidroxi-2'-Desoxiguanosina , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/urina , Estudos Transversais , Dano ao DNA , Desoxiguanosina/urina , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Japão , Masculino , Fatores de Risco
11.
PLoS One ; 19(3): e0298047, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38427672

RESUMO

In this study, we explored the effective capture of both cations and anions onto a single adsorbent. Acrylamide (AAm) served as the polymer backbone, onto which co-monomers sodium p-styrenesulfonate (SS) and N,N-dimethylaminopropyl acrylamide (DMAPAA) were grafted, creating ionized polymer hydrogel adsorbents. These adsorbents were engineered for the synergistic separation and recovery of heavy metal cations and anions from concentrated solutions, focusing specifically on industrially significant ions such as Ni2+-, Cu2+, Zn2+ and (Cr2O7)2-. The adsorption and desorption behaviors of the AAm terpolymer hydrogels were investigated across various pH solutions, considering the competition and concentrations of these specific metal ions. Moreover, the study delved into the effects of the internal pH environment within the hydrogel adsorbents, determining its impact on the type of metal adsorbed and the adsorption capacity. Our findings indicated that the adsorption of cations was enhanced with a higher proportion of SS relative to DMAPAA in the hydrogel. In contrast, significant anion capture occurred when the concentration of DMAPAA exceeded that of SS. However, equal ratios of SS and DMAPAA led to a noticeable reduction in the adsorption of both types of substrates, attributed to the counteractive nature of these co-monomers. To enhance the adsorption efficiency, it may be necessary to consider methods for micro-scale separation of the two types of monomers. Additionally, the adsorption capacity was observed to be directly proportional to the swelling capacity of the hydrogels. For complete desorption and separation of the cations and anions from the adsorbent, the application of concentrated NaOH solutions followed by HNO3 was found to be essential. Given the varying concentrations of cation and anion pollutants, often present in heavy metal factory effluents, it is crucial to fine-tune the ratios of DMAPAA and SS during the synthesis process. This adjustment ensures optimized efficiency in the decontamination and recovery of these significant heavy metal ions.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Hidrogéis , Acrilamida , Íons , Cátions , Ânions , Polímeros , Adsorção , Poluentes Químicos da Água/análise , Concentração de Íons de Hidrogênio , Cinética
12.
J Rural Med ; 19(1): 17-23, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38196807

RESUMO

Objectives: Approximately 17% of Japanese women have hemoglobin concentrations less than 12 g/dL. Therefore, anemia prevention and early intervention are crucial public health issues in Japan. This study aimed to identify the symptoms and characteristics of anemic individuals in the general adult population by comparing survey responses of individuals with anemia and without anemia visiting blood donation centers. Materials and Methods: This cross-sectional study used self-administered questionnaires. Individuals who visited two Japanese Red Cross Society blood donation centers in Fukushima Prefecture, Japan were included. Hemoglobin levels were measured at blood donation, and the levels of 13 g/dL for men and 12 g/dL for women were defined as anemia. Results: Of the 857 individuals analyzed, 530 were men and 327 were women, of whom 19 (3.6%) and 12 (3.7%) had low hemoglobin levels, respectively. Logistic regression analysis was performed in men, and the results showed that "lightheadedness" (odds ratio [OR]=8.4) and "depressive symptoms" (OR=3.6) were significantly associated with hemoglobin levels. None of the evaluated items were significantly associated with hemoglobin levels in women. Conclusion: Among healthy Japanese men, those who exhibit lightheadedness and depressive symptoms have an increased risk of anemia. Lightheadedness and depressive symptoms may be indicative of undiagnosed anemia in men, which necessitates greater clinical attention.

13.
Nat Mater ; 11(12): 1013-6, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23042414

RESUMO

Quasicrystals are metallic alloys that possess long-range, aperiodic structures with diffraction symmetries forbidden to conventional crystals. Since the discovery of quasicrystals by Schechtman et al. in 1984, there has been considerable progress in resolving their geometric structure. For example, it is well known that the golden ratio of mathematics and art occurs over and over again in their crystal structure. However, the characteristic properties of the electronic states--whether they are extended as in periodic crystals or localized as in amorphous materials--are still unresolved. Here we report the first observation of quantum (T = 0) critical phenomena of the Au-Al-Yb quasicrystal--the magnetic susceptibility and the electronic specific heat coefficient arising from strongly correlated 4f electrons of the Yb atoms diverge as T→0. Furthermore, we observe that this quantum critical phenomenon is robust against hydrostatic pressure. By contrast, there is no such divergence in a crystalline approximant, a phase whose composition is close to that of the quasicrystal and whose unit cell has atomic decorations (that is, icosahedral clusters of atoms) that look like the quasicrystal. These results clearly indicate that the quantum criticality is associated with the unique electronic state of the quasicrystal, that is, a spatially confined critical state. Finally we discuss the possibility that there is a general law underlying the conventional crystals and the quasicrystals.

14.
Arch Phys Med Rehabil ; 94(3): 467-73, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22975225

RESUMO

OBJECTIVE: To evaluate the diagnostic utility of the T reflexes elicited from the upper limb muscles during standardized volitional contraction monitored by a real-time integrating electromyographic analyzer. DESIGN: Prospective descriptive study. SETTING: Department of orthopedic surgery at a university hospital. PARTICIPANTS: Healthy subjects (n=80) evenly distributed across decades of age from 21 to 79 years, and 12 consecutive patients with a single cervical root lesion based on clinical and magnetic resonance imaging studies and diagnostic block. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Using a special hammer, which externally triggers the sweep on skin contact, we evoked T reflexes in the biceps (C5), brachioradialis (C6), triceps (C7), and the first dorsal interosseous muscles (C8). RESULTS: Simultaneous regression analyses yielded clinically useful upper limits of normative values for latencies, side-to-side differences, and amplitude ratios adjusted to age and arm span. Comparison of the T reflexes between the 2 sides localized the solitary root lesions with a high sensitivity (92%), specificity (81%), and accuracy (83%). T-reflex studies proved helpful to localize the lesion even in patients who solely complained of upper limb pain. CONCLUSIONS: The T reflexes with a standardized facilitation of the upper limb muscles provide a clinically useful, noninvasive measure to localize the C5 to C8 radiculopathies. This study contributes in reassessing the currently underused T reflex as an electrodiagnostic technique.


Assuntos
Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Radiculopatia/diagnóstico , Radiculopatia/fisiopatologia , Reflexo/fisiologia , Extremidade Superior/fisiologia , Adulto , Idoso , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Análise de Regressão , Sensibilidade e Especificidade
15.
Pathogens ; 12(5)2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37242360

RESUMO

Schistosome helminths infect over 200 million people across 78 countries and are responsible for nearly 300,000 deaths annually. However, our understanding of basic genetic pathways crucial for schistosome development is limited. The sex determining region Y-box 2 (Sox2) protein is a Sox B type transcriptional activator that is expressed prior to blastulation in mammals and is necessary for embryogenesis. Sox expression is associated with pluripotency and stem cells, neuronal differentiation, gut development, and cancer. Schistosomes express a Sox-like gene expressed in the schistosomula after infecting a mammalian host when schistosomes have about 900 cells. Here, we characterized and named this Sox-like gene SmSOXS1. SmSoxS1 protein is a developmentally regulated activator that localizes to the anterior and posterior ends of the schistosomula and binds to Sox-specific DNA elements. In addition to SmSoxS1, we have also identified an additional six Sox genes in schistosomes, two Sox B, one SoxC, and three Sox genes that may establish a flatworm-specific class of Sox genes with planarians. These data identify novel Sox genes in schistosomes to expand the potential functional roles for Sox2 and may provide interesting insights into early multicellular development of flatworms.

16.
Sci Adv ; 9(30): eadg2736, 2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37506206

RESUMO

Superconducting (SC) state has spin and orbital degrees of freedom, and spin-triplet superconductivity shows multiple SC phases because of the presence of these degrees of freedom. However, the observation of spin-direction rotation occurring inside the SC state (SC spin rotation) has hardly been reported. Uranium ditelluride, a recently found topological superconductor, exhibits various SC phases under pressure: SC state at ambient pressure (SC1), high-temperature SC state above 0.5 gigapascal (SC2), and low-temperature SC state above 0.5 gigapascal (SC3). We performed nuclear magnetic resonance (NMR) and ac susceptibility measurements on a single-crystal uranium ditelluride. The b axis spin susceptibility remains unchanged in SC2, unlike in SC1, and decreases below the SC2-SC3 transition with spin modulation. These unique properties in SC3 arise from the coexistence of two SC order parameters. Our NMR results confirm spin-triplet superconductivity with SC spin parallel to b axis in SC2 and unveil the remaining of spin degrees of freedom in SC uranium ditelluride.

17.
Nat Commun ; 13(1): 3517, 2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35725579

RESUMO

The preparation of air and thermally stable n-type carbon nanotubes is desirable for their further implementation in electronic and energy devices that rely on both p- and n-type material. Here, a series of guanidine and amidine bases with bicyclic-ring structures are used as n-doping reagents. Aided by their rigid alkyl functionality and stable conjugate acid structure, these organic superbases can easily reduce carbon nanotubes. n-Type nanotubes doped with guanidine bases show excellent thermal stability in air, lasting for more than 6 months at 100 °C. As an example of energy device, a thermoelectric p/n junction module is constructed with a power output of ca. 4.7 µW from a temperature difference of 40 °C.

18.
Soc Sci Med ; 306: 115142, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35716553

RESUMO

RATIONALE: Mobile technology has been widely utilized as an effective healthcare tool during the COVID-19 pandemic. Notably, over 50 countries have released contact-tracing apps to trace and contain infection chains. While earlier studies have examined obstacles to app uptake and usage, whether and how this uptake affects users' behavioral patterns is not well understood. This is crucial because uptake can theoretically increase or decrease behavior that carries infection risks. OBJECTIVE: The goal of this study is to evaluate the impact of app uptake on the time spent out of home in Japan. It tests four potential underlying mechanisms that drive the uptake effect: compliance with stay-at-home requirements, learning about infection risk, reminders, and commitment device. METHOD: We use unique nationwide survey data collected from 4,379 individuals aged between 20 and 69 in December 2020 and February 2021 in Japan. Japan has features suitable for this exercise. The Japanese government released a contact tracing app in June 2020, which sends a warning message to users who have been in close contact with an infected person. We conduct a difference-in-differences estimation strategy combined with the entropy balancing method. RESULTS: App uptake reduces the time spent out of home. Sensitivity analysis shows that it cannot be explained by unobserved confounders. Importantly, the impact is large even among users who have not received a warning message from the app, and even larger for those with poor self-control ability. Furthermore, individuals' self-control ability is negatively associated with the uptake decision, supporting our hypothesis that the apps serve as a commitment device. CONCLUSIONS: It may be beneficial to encourage citizens to uptake contact tracing apps and other forms of commitment devices. This study also contributes to the literature on mobile health (mHealth) by demonstrating its efficacy as a commitment device.


Assuntos
COVID-19 , Aplicativos Móveis , Autocontrole , Telemedicina , Adulto , Idoso , Tecnologia Biomédica , COVID-19/epidemiologia , COVID-19/prevenção & controle , Busca de Comunicante , Humanos , Japão , Pessoa de Meia-Idade , Pandemias/prevenção & controle , Tecnologia , Adulto Jovem
19.
Front Cell Infect Microbiol ; 12: 794323, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35178354

RESUMO

BACKGROUND: Polymerase chain reaction (PCR) is an important means by which to study the urine microbiome and is emerging as possible alternative to urine cultures to identify pathogens that cause urinary tract infection (UTI). However, PCR is limited by its inability to differentiate DNA originating from viable, metabolically active versus non-viable, inactive bacteria. This drawback has led to concerns that urobiome studies and PCR-based diagnosis of UTI are confounded by the presence of relic DNA from non-viable bacteria in urine. Propidium monoazide (PMA) dye can penetrate cells with compromised cell membranes and covalently bind to DNA, rendering it inaccessible to amplification by PCR. Although PMA has been shown to differentiate between non-viable and viable bacteria in various settings, its effectiveness in urine has not been previously studied. We sought to investigate the ability of PMA to differentiate between viable and non-viable bacteria in urine. METHODS: Varying amounts of viable or non-viable uropathogenic E. coli (UTI89) or buffer control were titrated with mouse urine. The samples were centrifuged to collect urine sediment or not centrifuged. Urine samples were incubated with PMA and DNA cross-linked using blue LED light. DNA was isolated and uidA gene-specific PCR was performed. For in vivo studies, mice were inoculated with UTI89, followed by ciprofloxacin treatment or no treatment. After the completion of ciprofloxacin treatment, an aliquot of urine was plated on non-selective LB agar and another aliquot was treated with PMA and subjected to uidA-specific PCR. RESULTS: PMA's efficiency in excluding DNA signal from non-viable bacteria was significantly higher in bacterial samples in phosphate-buffered saline (PBS, dCT=13.69) versus bacterial samples in unspun urine (dCT=1.58). This discrepancy was diminished by spinning down urine-based bacterial samples to collect sediment and resuspending it in PBS prior to PMA treatment. In 3 of 5 replicate groups of UTI89-infected mice, no bacteria grew in culture; however, there was PCR amplification of E. coli after PMA treatment in 2 of those 3 groups. CONCLUSION: We have successfully developed PMA-based PCR methods for amplifying DNA from live bacteria in urine. Our results suggest that non-PMA bound DNA from live bacteria can be present in urine, even after antibiotic treatment. This indicates that viable but non-culturable E. coli can be present following treatment of UTI, and may explain why some patients have persistent symptoms but negative urine cultures following UTI treatment.


Assuntos
Escherichia coli Uropatogênica , Animais , Azidas , DNA Bacteriano/genética , Humanos , Camundongos , Viabilidade Microbiana , Reação em Cadeia da Polimerase/métodos , Propídio/análogos & derivados , Reação em Cadeia da Polimerase em Tempo Real/métodos , Escherichia coli Uropatogênica/genética , Escherichia coli Uropatogênica/metabolismo
20.
PLoS Negl Trop Dis ; 16(2): e0010176, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35167594

RESUMO

Urogenital schistosomiasis remains a major public health concern worldwide. In response to egg deposition, the host bladder undergoes gross and molecular morphological changes relevant for disease manifestation. However, limited mechanistic studies to date imply that the molecular mechanisms underlying pathology are not well-defined. We leveraged a mouse model of urogenital schistosomiasis to perform for the first time, proteome profiling of the early molecular events that occur in the bladder after exposure to S. haematobium eggs, and to elucidate the protein pathways involved in urogenital schistosomiasis-induced pathology. Purified S. haematobium eggs or control vehicle were microinjected into the bladder walls of mice. Mice were sacrificed seven days post-injection and bladder proteins isolated and processed for proteome profiling using mass spectrometry. We demonstrate that biological processes including carcinogenesis, immune and inflammatory responses, increased protein translation or turnover, oxidative stress responses, reduced cell adhesion and epithelial barrier integrity, and increased glucose metabolism were significantly enriched in S. haematobium infection. S. haematobium egg deposition in the bladder results in significant changes in proteins and pathways that play a role in pathology. Our findings highlight the potential bladder protein indicators for host-parasite interplay and provide new insights into the complex dynamics of pathology and characteristic bladder tissue changes in urogenital schistosomiasis. The findings will be relevant for development of improved interventions for disease control.


Assuntos
Interações Hospedeiro-Parasita/fisiologia , Schistosoma haematobium/patogenicidade , Esquistossomose Urinária/fisiopatologia , Bexiga Urinária/parasitologia , Animais , Modelos Animais de Doenças , Feminino , Camundongos Endogâmicos BALB C , Óvulo , Proteoma , Bexiga Urinária/metabolismo , Bexiga Urinária/patologia
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