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1.
Gigascience ; 13(1)2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38372702

RESUMEN

BACKGROUND: Lice (Psocodea: Phthiraptera) are one important group of parasites that infects birds and mammals. It is believed that the ancestor of parasitic lice originated on the ancient avian host, and ancient mammals acquired these parasites via host-switching from birds. Here we present the first chromosome-level genome of Menopon gallinae in Amblycera (earliest diverging lineage of parasitic lice). We explore the transition of louse host-switching from birds to mammals at the genomic level by identifying numerous idiosyncratic genomic variations. RESULTS: The assembled genome is 155 Mb in length, with a contig N50 of 27.42 Mb. Hi-C scaffolding assigned 97% of the bases to 5 chromosomes. The genome of M. gallinae retains a basal insect repertoire of 11,950 protein-coding genes. By comparing the genomes of lice to those of multiple representative insects in other orders, we discovered that gene families of digestion, detoxification, and immunity-related are generally conserved between bird lice and mammal lice, while mammal lice have undergone a significant reduction in genes related to chemosensory systems and temperature. This suggests that mammal lice have lost some of these genes through the adaption to environment and temperatures after host-switching. Furthermore, 7 genes related to hematophagy were positively selected in mammal lice, suggesting their involvement in the hematophagous behavior. CONCLUSIONS: Our high-quality genome of M. gallinae provides a valuable resource for comparative genomic research in Phthiraptera and facilitates further studies on adaptive evolution of host-switching within parasitic lice.


Asunto(s)
Amblycera , Parásitos , Animales , Aves de Corral , Cromosomas , Mamíferos
2.
RSC Adv ; 13(42): 29689-29694, 2023 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-37822652

RESUMEN

A series of sulfonate anions paired aromatic triangular palladium clusters 3-7, abbreviated as [Pd3]+[ArSO3]-, were synthesized using a simple "one pot" method, and gave excellent isolated yields (90-95%). Their structures and properties have been fully characterized and further investigated by fluorescence, single crystal X-ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). In varying organic solvents, they presented apparently stronger absorption and emission in MeOH, driven by the combined interactions of hydrogen bonds and polarity. The crystallographic data demonstrated that the methyl orange ion stabilized complex 7 possessed a D3h symmetric metallic core which was still coplanar and almost equilateral, jointly influenced by the giant hindrance and milder donating effect from the sulfonate. The binding energies for Pdn+ 3d5/2 and Pdn+ 3d3/2 measured by XPS presented at 336.55 and 342.00 eV, respectively. These data were much lower than that of a usual Pd2+ 3d and significantly higher than that of a Pd0 species, further proving the unified palladium valence state (+4/3) in the tri-palladium core and its aromaticity featured by the cyclic electron delocalization.

3.
J Dermatolog Treat ; 34(1): 2229464, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37394952

RESUMEN

INTRODUCTION: Atopic dermatitis (AD) exhibits difference in immune polarization between Caucasians and Asian races due to which an evaluation of the efficacy and safety of Pimecrolimus (PIM) in Asian population is called for. The current study addresses the need via a sub-group analysis of the PETITE study (NCT00120523) to evaluate the safety and efficacy of PIM in Chinese infants. MATERIALS AND METHODS: Patients with AD (≥3 months-<12 months of age) were randomized in a 1:1 ratio to either PIM 1% cream or topical corticosteroids (TCS). The primary endpoint was safety. The secondary endpoint was efficacy. RESULTS: 120 patients were randomized to either PIM 1% or TCS (n = 61 for PIM, n = 59 for TCS). The most often reported adverse events were reported by similar proportions of patients treated with PIM or TCS. There was a progressive increase in overall IGA treatment success in infants treated with PIM (82.9%, p < .05, 95% CI: 70.4, 95.3) after 26 weeks which was comparable to the TCS group (88.5%, p < .05, 95% CI: 79.8, 97.1). CONCLUSION: PIM showed an early and sustained efficacy in the Chinese sub-population with a substantial corticosteroid-sparing effect in patients with AD.


Asunto(s)
Dermatitis Atópica , Fármacos Dermatológicos , Tacrolimus , Humanos , Lactante , Dermatitis Atópica/tratamiento farmacológico , Fármacos Dermatológicos/administración & dosificación , Fármacos Dermatológicos/efectos adversos , Fármacos Dermatológicos/uso terapéutico , Pueblos del Este de Asia , Tacrolimus/administración & dosificación , Tacrolimus/efectos adversos , Tacrolimus/análogos & derivados , Tacrolimus/uso terapéutico , Resultado del Tratamiento , Administración Tópica , Glucocorticoides/administración & dosificación , Glucocorticoides/efectos adversos , Glucocorticoides/uso terapéutico , Crema para la Piel
4.
Toxicol Res (Camb) ; 11(4): 628-643, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36051664

RESUMEN

Arsenic, a widely existing environmental contaminant, is recognized to be toxic to multiple organs. Exposure to arsenic results in liver damage via excessive production of reactive oxidative species (ROS). PIN1 regulates the levels of ROS. N-acetyl-L-cysteine (NAC) is an ROS scavenger that protects the hepatic functions. Whether PIN1 plays a regulatory role in NAC-mediated antagonism against arsenic hepatotoxicity remains largely unknown. In our study, the protective effects of NAC against arsenic (NaAsO2)-induced hepatotoxicity were evaluated in vitro and in vivo. Arsenic exposure induced cytotoxicity by increasing the intracellular ROS production, impairing mitochondrial function and inducing apoptosis in L02 hepatocytes. Overexpression of PIN1 markedly protected against arsenic cytotoxicity, decreased ROS levels, and mitigated mitochondrial dysfunction and apoptosis in L02 cells. However, loss of PIN1 further aggravated arsenic-induced cytotoxicity and abolished the protective effects of NAC in L02 cells. An in vivo study showed that pretreatment with NAC rescued arsenic-induced liver injury by restoring liver function and suppressing hepatic oxidative stress. Overexpression of PIN1 in mice transfected with AAV-Pin1 relieved arsenic-induced liver dysfunction and hepatic oxidative stress. Taken together, our study identified PIN1 as a novel intervention target for antagonizing arsenic-induced hepatotoxicity, highlighting a new pharmacological mechanism of NAC targeting PIN1 in antagonism against arsenic toxicity.

5.
Dalton Trans ; 51(22): 8786-8794, 2022 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-35616208

RESUMEN

The Li2MoO3 (LMO) material is one promising cathode material for lithium-ion batteries due to its high specific capacity and absence of oxygen release. However, its surface instability in air and poor conductivity have limited its application. To solve these problems, the Ru element has been successfully introduced into the LMO lattice with the aid of the molten salt method. XRD and TEM characterization showed that the introduction of Ru does not change the crystal structure but expands the crystal plane spacing of the {001} facets, which is further evidenced by density functional theory (DFT) calculations. XPS and EDS tests indicated that the introduction of Ru inhibits the oxidation of Mo species and leads to a more uniform distribution of the material. In addition, DFT calculations revealed that covalent interactions are formed between Mo4d/Ru4d and O2p orbitals, leading to a significant reduction of the band gap. Therefore, Ru-doped samples exhibit good electrochemical performances. The initial discharge capacity of an LMRO-2 sample reaches 299.1 mA h g-1 at a 1C rate, and the capacity remains at 125.2 mA h g-1 after 100 cycles. In comparison, the initial discharge capacity of pure phase sample LMO is only 250.5 mA h g-1 under the same conditions, and the capacity remains only at 76.5 mA h g-1 after 100 cycles. The present results confirmed that Ru doping is an effective strategy to improve the performance of the LMO cathode material.

6.
Zookeys ; 1090: 113-128, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35586841

RESUMEN

We propose the genus Flospes gen. nov. for two new species, Flospesguangxiensis sp. nov. and Flospesviridipennis sp. nov., obtained from Guangxi and Hainan provinces, China, respectively, based on male genitalia traits. Three other species with similar genitalia are placed in the new genus: Flospesfujianensis (Wang et al., 1999), comb. nov., Flospeshainanensis (He et al., 2010), comb. nov., and Flospesdenticulatus (Liu & Shi, 2011), comb. nov. The new species are described, illustrated, and their ranges are given.

7.
J Hazard Mater ; 435: 128942, 2022 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-35468398

RESUMEN

Metabolic disorders induced by arsenic exposure have attracted great public concern. However, it remains unclear whether hypothalamus-based central regulation mechanisms are involved in this process. Here, we exposed mice to 100 µg/L arsenic in drinking water and established a chronic arsenic exposure model. Our study revealed that chronic arsenic exposure caused metabolic disorders in mice including impaired glucose metabolism and decreased energy expenditure. Arsenic exposure also impaired glucose sensing and the activation of proopiomelanocortin (POMC) neurons in the hypothalamus. In particular, arsenic exposure damaged the plasticity of hypothalamic astrocytic process. Further research revealed that arsenic exposure inhibited the expression of sex-determining region Y-Box 2 (SOX2), which decreased the expression level of insulin receptors (INSRs) and the phosphorylation of AKT. The conditional deletion of astrocytic SOX2 exacerbated arsenic-induced effects on metabolic disorders, the impairment of hypothalamic astrocytic processes, and the inhibition of INSR/AKT signaling. Furthermore, the arsenic-induced impairment of astrocytic processes and inhibitory effects on INSR/AKT signaling were reversed by SOX2 overexpression in primary hypothalamic astrocytes. Together, we demonstrated here that chronic arsenic exposure caused metabolic disorders by impairing SOX2-modulated hypothalamic astrocytic process plasticity in mice. Our study provides evidence of novel central regulatory mechanisms underlying arsenic-induced metabolic disorders and emphasizes the crucial role of SOX2 in regulating the process plasticity of adult astrocytes.


Asunto(s)
Arsénico , Enfermedades Metabólicas , Animales , Arsénico/metabolismo , Arsénico/toxicidad , Hipotálamo/metabolismo , Enfermedades Metabólicas/metabolismo , Ratones , Proopiomelanocortina/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo
8.
Zootaxa ; 5124(5): 585-593, 2022 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-35391099

RESUMEN

Here we report two new species of the swordtail crickets (Orthoptera: Trigonidiidae; Trigonidiinae) from Yunnan and Guangxi Province, China. One species (Trigonidium rubrumoculus sp. nov.) belongs to the genus Trigonidium, and we describe a new genus for the other species (Polycomus gen. nov., Polycomus exspiravit sp. nov.). The new genus resembles Amusurgus Brunner von Wattenwyl, 1893 in appearance but differs in the structure of the male genitalia. Descriptions, illustrations, and distributions of these new species are provided.


Asunto(s)
Gryllidae , Ortópteros , Distribución Animal , Estructuras Animales , Animales , Tamaño Corporal , China , Masculino , Tamaño de los Órganos
9.
Zootaxa ; 5092(4): 473-479, 2022 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-35391191

RESUMEN

Here we describe two new species of ground crickets from Yunnan Province, China (Homonemobius brevipennis sp. nov. and Pteronemobius osuviridis sp. nov.). Descriptions, illustrations, and distributions of these new species are provided.


Asunto(s)
Gryllidae , Ortópteros , Distribución Animal , Estructuras Animales , Animales , Tamaño Corporal , China , Tamaño de los Órganos
10.
Front Public Health ; 9: 771508, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34881219

RESUMEN

Background: With the global popularity of communication devices such as mobile phones, there are increasing concerns regarding the effect of radiofrequency electromagnetic radiation (RF-EMR) on the brain, one of the most important organs sensitive to RF-EMR exposure at 1,800 MHz. However, the effects of RF-EMR exposure on neuronal cells are unclear. Neurite outgrowth plays a critical role in brain development, therefore, determining the effects of 1,800 MHz RF-EMR exposure on neurite outgrowth is important for exploring its effects on brain development. Objectives: We aimed to investigate the effects of 1,800 MHz RF-EMR exposure for 48 h on neurite outgrowth in neuronal cells and to explore the associated role of the Rap1 signaling pathway. Material and Methods: Primary hippocampal neurons from C57BL/6 mice and Neuro2a cells were exposed to 1,800 MHz RF-EMR at a specific absorption rate (SAR) value of 4 W/kg for 48 h. CCK-8 assays were used to determine the cell viability after 24, 48, and 72 h of irradiation. Neurite outgrowth of primary hippocampal neurons (DIV 2) and Neuro2a cells was observed with a 20 × optical microscope and recognized by ImageJ software. Rap1a and Rap1b gene expressions were detected by real-time quantitative PCR. Rap1, Rap1a, Rap1b, Rap1GAP, and p-MEK1/2 protein expressions were detected by western blot. Rap1-GTP expression was detected by immunoprecipitation. The role of Rap1-GTP was assessed by transfecting a constitutively active mutant plasmid (Rap1-Gly_Val-GFP) into Neuro2a cells. Results: Exposure to 1,800 MHz RF-EMR for 24, 48, and 72 h at 4 W/kg did not influence cell viability. The neurite length, primary and secondary neurite numbers, and branch points of primary mouse hippocampal neurons were significantly impaired by 48-h RF-EMR exposure. The neurite-bearing cell percentage and neurite length of Neuro2a cells were also inhibited by 48-h RF-EMR exposure. Rap1 activity was inhibited by 48-h RF-EMR with no detectable alteration in either gene or protein expression of Rap1. The protein expression of Rap1GAP increased after 48-h RF-EMR exposure, while the expression of p-MEK1/2 protein decreased. Overexpression of constitutively active Rap1 reversed the decrease in Rap1-GTP and the neurite outgrowth impairment in Neuro2a cells induced by 1,800 MHz RF-EMR exposure for 48 h. Conclusion: Rap1 activity and related signaling pathways are involved in the disturbance of neurite outgrowth induced by 48-h 1,800 MHz RF-EMR exposure. The effects of RF-EMR exposure on neuronal development in infants and children deserve greater focus.


Asunto(s)
Hipocampo , Neuronas , Animales , Radiación Electromagnética , Guanosina Trifosfato/metabolismo , Guanosina Trifosfato/farmacología , Hipocampo/metabolismo , Hipocampo/efectos de la radiación , Humanos , Ratones , Ratones Endogámicos C57BL , Proyección Neuronal , Neuronas/metabolismo , Neuronas/efectos de la radiación
11.
Zootaxa ; 5011(1): 1-70, 2021 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-34810470

RESUMEN

The article reviewed species of genera of Pteronemobius Jacobson, 1904, Speonemobius Chopard, 1924, Parapteronemobius Furukawa, 1970, Dianemobius Vickery, 1973, Polionemobius Gorochov, 1983, Giganemobius Shen He, 2020, Qionemobius Shen He, 2020 and proposed four new genera, Claranemobius He Ma, gen. n., Erexitonemobius He Ma, gen. n., Fibunemobius He Ma, gen. n. and Impetunemobius He Ma, gen. n., and nine new species, Claranemobius yaoquensis He Ma, sp. n., Erexitonemobius bellus He Ma, sp. n., Fibunemobius tamquam He Ma, sp. n., Homonemobius amare He Ma, sp. n., Impetunemobius brunneis He Ma, sp. n., Polionemobius Chayuensis He Ma, sp. n., Pteronemobius (Pteronemobius) litore He Ma, sp. n., Pteronemobius (Pteronemobius) choui He Ma, sp. n. and Speonemobius minor He Ma, sp. n..


Asunto(s)
Gryllidae , Ortópteros , Distribución Animal , Estructuras Animales , Animales , Tamaño Corporal , China , Tamaño de los Órganos
12.
ACS Appl Mater Interfaces ; 13(28): 33272-33281, 2021 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-34242016

RESUMEN

Advanced ferroelectrics with a combination of large dielectric response and good temperature stability are crucial for many technologically important electronic devices and electrical storage/power equipment. However, the two key factors usually do not go hand in hand, and achieving high permittivity is normally at the expense of sacrificing temperature stability. This trade-off relation is eased but not fundamentally remedied using relaxor-type materials which are known to have a diffuse permittivity peak at their relaxor transition temperatures. Here, we report an anomalous trirelaxor phenomenon in a barium titanate system and show that it can lead to a giant dielectric permittivity (εr ≈ 18 000) over a wide temperature range (Tspan ≈ 34K), which successfully overcomes a long-standing permittivity-stability trade-off. Moreover, the enhancement in the dielectric properties also yields a desired temperature-insensitive electrocaloric performance for the trirelaxor ferroelectrics. Microstructure characterization and phase-field simulations reveal a mixture of tetragonal, orthorhombic, and rhombohedral polar nanoregions over a broad temperature window in trirelaxor ferroelectrics, which is responsible for this combination of giant dielectric permittivity and good temperature stability. This finding provides an effective approach in designing advanced ferroelectrics with high performance and thermal stability.

13.
Ecotoxicol Environ Saf ; 223: 112554, 2021 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-34332247

RESUMEN

Arsenic is one of the most common environmental pollutants. Neurotoxicity induced by arsenic has become a major public health concern. However, the effects of arsenic-induced neurotoxicity in the brain and the underlying molecular mechanisms are not well understood. N-acetyl-cysteine (NAC) is a thiol-based antioxidant that can antagonize heavy metal-induced neurotoxicity by scavenging reactive oxygen species (ROS). Here, we used the mouse oligodendrocyte precursor cell (OPC) line Oli-neu to explore the neurotoxic effects of arsenic and the protective effects of NAC. We found that arsenic exposure decreased cell viability, increased oxidative stress, caused mitochondrial dysfunction, and led to apoptosis of Oli-neu cells. Furthermore, we revealed that NAC treatment reversed these neurotoxic effects of arsenic. TMEM179, a key membrane protein, was found highly expressed in OPCs and to be an important factor in maintaining mitochondrial functions. We found that TMEM179 played a critical role in mediating the neurotoxic effects of arsenic and the protective role of NAC. PKCß is a downstream factor through which TMEM179 regulates the expression of apoptosis-related proteins. This study improves our understanding of the neurotoxic effects and mechanisms of arsenic exposure and the protective effects of NAC. It also identifies a potential molecular target, TMEM179, for the treatment of arsenic-induced neurotoxicity.


Asunto(s)
Acetilcisteína , Arsénico , Acetilcisteína/metabolismo , Acetilcisteína/farmacología , Animales , Apoptosis , Arsénico/metabolismo , Arsénico/toxicidad , Ratones , Mitocondrias/metabolismo , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo
14.
Sci Total Environ ; 783: 147014, 2021 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-34088129

RESUMEN

Nickel (Ni) is a heavy metal that is both an environmental pollutant and a threat to human health. However, the effects of Ni on the central nervous system in susceptible populations have not been well established. In the present study, the neurotoxicity of Ni and its underlying mechanism were investigated in vivo and in vitro. Ni exposure through drinking water (10 mg Ni/L, 12 weeks) caused learning and memory impairment in mice. Reduced dendrite complexity was observed in both Ni-exposed mouse hippocampi and Ni-treated (200 µM, 72 h) primary cultured hippocampal neurons. The levels of histone acetylation, especially at histone H3 lysine 9 (H3K9ac), were reduced in Ni-exposed mouse hippocampi and cultured neurons. RNA sequencing and chromatin immunoprecipitation (ChIP) sequencing analyses revealed that H3K9ac-modulated gene expression were downregulated. Treatment with sodium butyrate, a histone deacetylase inhibitor, attenuated Ni-induced H3K9 hypoacetylation, neural gene downregulation and dendrite complexity reduction in cultured neurons. Sodium butyrate also restored Ni-induced memory impairment in mice. These results indicate that Ni-induced H3K9 hypoacetylation may be a contributor to the neurotoxicity of Ni. The finding that Ni disturbs histone acetylation in the nervous system may provide new insight into the health risk of chronic Ni exposure.


Asunto(s)
Histonas , Níquel , Acetilación , Animales , Regulación hacia Abajo , Histonas/metabolismo , Ratones , Níquel/toxicidad , Procesamiento Proteico-Postraduccional
15.
Zootaxa ; 4950(3): zootaxa.4950.3.11, 2021 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-33903434

RESUMEN

A new species, Rhicnogryllus nanlingensis sp. n., was reported from Guangdong, China. This was the first time of Rhicnogryllus was recorded from China. Description and illustrations for the new species were provided.


Asunto(s)
Gryllidae , Distribución Animal , Estructuras Animales , Animales , Tamaño Corporal , China , Gryllidae/clasificación , Tamaño de los Órganos , Ortópteros
16.
Front Cell Dev Biol ; 9: 657623, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33912567

RESUMEN

The increasing intensity of environmental radiofrequency electromagnetic fields (RF-EMF) has increased public concern about its health effects. Of particular concern are the influences of RF-EMF exposure on the development of the brain. The mechanisms of how RF-EMF acts on the developing brain are not fully understood. Here, based on high-throughput RNA sequencing techniques, we revealed that transcripts related to neurite development were significantly influenced by 1800 MHz RF-EMF exposure during neuronal differentiation. Exposure to RF-EMF remarkably decreased the total length of neurite and the number of branch points in neural stem cells-derived neurons and retinoic acid-induced Neuro-2A cells. The expression of Eph receptors 5 (EPHA5), which is required for neurite outgrowth, was inhibited remarkably after RF-EMF exposure. Enhancing EPHA5 signaling rescued the inhibitory effects of RF-EMF on neurite outgrowth. Besides, we identified that cAMP-response element-binding protein (CREB) and RhoA were critical downstream factors of EPHA5 signaling in mediating the inhibitory effects of RF-EMF on neurite outgrowth. Together, our finding revealed that RF-EMF exposure impaired neurite outgrowth through EPHA5 signaling. This finding explored the effects and key mechanisms of how RF-EMF exposure impaired neurite outgrowth and also provided a new clue to understanding the influences of RF-EMF on brain development.

17.
Zootaxa ; 4942(1): zootaxa.4942.1.3, 2021 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-33756911

RESUMEN

The genus Ornebius Guérin-Méneville, 1844 was divided into five species groups based on the structure of the male genitalia. Three new species of Ornebius were described from the Chinese provinces of Hainan, Guangxi and Guangdong. Type specimens are deposited at the Museum of Flora and Fauna of Shaanxi Normal University, Xi'an, China (SNNU).


Asunto(s)
Gryllidae , Ortópteros , Distribución Animal , Estructuras Animales , Animales , Tamaño Corporal , China , Masculino , Tamaño de los Órganos
18.
Zootaxa ; 4942(3): zootaxa.4942.3.4, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33757058

RESUMEN

The Itarinae includes two genera and 60 species world-wide. Ten species are recorded from China. All Chinese species were reviewed in this study. Females of the most species were described and illustrated. Keys based on characters of male and female for Chinese species were provided respectively. As well as, a new species and revised species distribution of Itara Walker, 1869 were reported. Two types of coloration (dark and light colors) of Parapentacentrus fuscus Gorochov, 1988 were discovered and taxonomic problem of the genus Parapentacentrus Shiraki, 1930 were discussed.


Asunto(s)
Gryllidae , Ortópteros , Distribución Animal , Estructuras Animales , Animales , Tamaño Corporal , China , Femenino , Masculino , Tamaño de los Órganos
19.
Dermatol Ther ; 33(2): e13223, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31917488

RESUMEN

Fox-Fordyce disease (FFD) is a rare pruritic dermatosis whose etiology has not been fully explored. It is mostly seen in women and presents as pruritic follicular papules at the apocrine (gland-bearing) regions, including the axilla, groins, perineum, and areola mammae, as well as the umbilicus. Treatment for FFD is extremely challenging in that there is no curative treatment for it. We report the case of a 26-year-old woman who was refractory to many treatments but who responded to calcipotriol betamethasone with rapid remission of her symptoms.


Asunto(s)
Enfermedad de Fox-Fordyce , Remoción del Cabello , Adulto , Axila , Betametasona/uso terapéutico , Calcitriol/análogos & derivados , Femenino , Enfermedad de Fox-Fordyce/diagnóstico , Enfermedad de Fox-Fordyce/tratamiento farmacológico , Humanos
20.
Macromol Rapid Commun ; 40(21): e1900406, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31557369

RESUMEN

Thermal stability of polymer structure is a key to achieve stable energy density at elevated temperature for ferroelectric-polymer-based capacitors. Here, a poly (vinylidene fluoride) / polymethyl methacrylate (PMMA) blend with a stabilized spherulite structure displaying steady energy density around 7.8-9.8 J cm-3 across the temperature range up to 70 °C is reported, which outperforms most neat ferroelectric polymers at elevated temperature. The microstructure of the blend observed by atomic force microscopy exhibits an alternating lamellar structure (crystalline/mixed amorphous layers) within spherulites, which might be rationalized by PMMA being gradually expelled from the spherulite and finally staying between PVDF lamellae during crystallization. The structure with rigid amorphous layers can induce a spatial confinement effect of chain motion and structural change under thermal stress, which is evidenced by temperature-insensitive long period in small-angle X-ray scattering measurements. The enhanced thermal stability of energy storage can be attributed to the constraint on free volume and carrier transportation caused by the spatial confinement. Our findings provide a strategy to attain temperature-stable high-energy-density ferroelectric polymers for energy storage capacitors.


Asunto(s)
Polimetil Metacrilato/química , Polivinilos/química , Temperatura , Dispersión del Ángulo Pequeño , Difracción de Rayos X
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