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1.
Inorg Chem ; 2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34813329

RESUMO

We report the isolation of vanadium(II) in a metal-organic framework (MOF) by the reaction of the chloride-capped secondary building unit in the all-vanadium(III) V-MIL-101 (1) with 1,4-bis(trimethylsilyl)-2,3,5,6-tetramethyl-1,4-dihydropyrazine. The reduced material, 2, has a secondary building unit with the formal composition [VIIV2III], with each metal ion presenting one open coordination site. Subsequent reaction with O2 yields a side-on η2 vanadium-superoxo species, 3. The MOF featuring V(III)-superoxo moieties exhibits a mild enhancement in the isosteric enthalpy of adsorption for methane compared to the parent V-MIL-101. We present this synthetic methodology as a potentially broad way to access low-valent open metal sites within MOFs without causing a loss of crystallinity or porosity. The low-valent sites can serve as isolable intermediates to access species otherwise inaccessible by direct synthesis.

2.
Theor Appl Genet ; 2021 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-34562124

RESUMO

KEY MESSAGE: A SNP mutation in Clbl gene encoding TERMINAL FLOWER 1 protein is responsible for watermelon branchless. Lateral branching is one of the most important traits, which directly determines plant architecture and crop productivity. Commercial watermelon has the characteristics of multiple lateral branches, and it is time-consuming and labor-costing to manually remove the lateral branches in traditional watermelon cultivation. In our present study, a lateral branchless trait was identified in watermelon material WCZ, and genetic analysis revealed that it was controlled by a single recessive gene, which named as Clbl (Citrullus lanatus branchless). A bulked segregant sequencing (BSA-seq) and linkage analysis was conducted to primarily map Clbl on watermelon chromosome 4. Next-generation sequencing-aided marker discovery and a large mapping population consisting of 1406 F2 plants were used to further map Clbl locus into a 9011-bp candidate region, which harbored only one candidate gene Cla018392 encoding a TERMINAL FLOWER 1 protein. Sequence comparison of Cla018392 between two parental lines revealed that there was a SNP detected from C to A in the coding region in the branchless inbred line WCZ, which resulted in a mutation from alanine (GCA) to glutamate (GAA) at the fourth exon. A dCAPS marker was developed from the SNP locus, which was co-segregated with the branchless phenotype in both BC1 and F2 population, and it was further validated in 152 natural watermelon accessions. qRT-PCR and in situ hybridization showed that the expression level of Cla018392 was significantly reduced in the axillary bud and apical bud in branchless line WCZ. Ectopic expression of ClTFL1 in Arabidopsis showed an increased number of lateral branches. The results of this study will be helpful for better understanding the molecular mechanism of lateral branch development in watermelon and for the development of marker-assisted selection (MAS) for new branchless watermelon cultivars.

3.
Angew Chem Int Ed Engl ; 60(44): 23784-23789, 2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34472695

RESUMO

We report the isolation and characterization of a series of trinickel complexes with 2,3,6,7,10,11-hexaoxytriphenylene (HOTP), [(Me3 TPANi)3 (HOTP)](BF4 )n (Me3 TPA=N,N,N-tris[(6-methyl-2-pyridyl)methyl]amine) (n=2, 3, 4 for complexes 1, 2, 3). These complexes comprise a redox ladder whereby the HOTP core displays increasingly quinoidal character as its formal oxidation state changes from -4, to -3, and -2 in 1, 2, and 3, respectively. No formal oxidation state changes occur on Ni, allowing the isolation of singlet diradical, monoradical, and closed-shell configurations for HOTP in 1, 2, and 3, respectively, with a concomitant decrease in the spin coupling strength upon oxidation. Because the three complexes can be considered models of the smallest building blocks of 2D conductive metal-organic frameworks such as Ni9 HOTP4 , these results serve as possible inspiration for the construction of extended materials with targeted electric and magnetic properties.

4.
Sci Rep ; 11(1): 17423, 2021 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-34465797

RESUMO

We aimed to elucidate the differences in genomic methylation patterns between ADLI and non-ADLI patients to identify DNA methylation-based biomarkers. Genome-wide DNA methylation patterns were obtained using Infinium MethylationEPIC (EPIC) BeadChip array to analyze 14 peripheral blood samples (7 ADLI cases, 7 non-ADLI controls). Changes in the mRNA and DNA methylation in the target genes of another 120 peripheral blood samples (60 ADLI cases, 60 non-ADLI controls) were analyzed by real-time polymerase chain reaction and pyrosequencing, respectively. A total of 308 hypermethylated CpG sites and 498 hypomethylated CpG sites were identified. Significantly, hypermethylated CpG sites cg06961147 and cg24666046 in TANC1 associated with ADLI was identified by genome-wide DNA methylation profiling. The mRNA expression of TANC1 was lower in the cases compared to the controls. Pyrosequencing validated these two differentially methylated loci, which was consistent with the results from the EPIC BeadChip array. Receiver operating characteristic analysis indicated that the area under the curve of TANC1 (cg06961147, cg24666046, and their combinations) was 0.812, 0.842, and 0.857, respectively. These results indicate that patients with ADLI have different genomic methylation patterns than patients without ADLI. The hypermethylated differentially methylated site cg06961147 combined with cg24666046 in TANC1 provides evidence for the diagnosis of ADLI.


Assuntos
Antituberculosos/efeitos adversos , Biomarcadores/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Metilação de DNA , Proteínas de Membrana/genética , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose/tratamento farmacológico , Adulto , Estudos de Casos e Controles , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Ilhas de CpG , Epigênese Genética , Feminino , Humanos , Masculino , Proteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Regiões Promotoras Genéticas , Tuberculose/microbiologia
5.
J Vis Exp ; (173)2021 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-34369927

RESUMO

Microplastics (MPs) are becoming a global concern due to the potential risk to human health. Case studies of plastic products (i.e., plastic single-use cups and kettles) indicate that MP release during daily use can be extremely high. Precisely determining the MP release level is a crucial step to identify and quantify the exposure source and assess/control the corresponding risks stemming from this exposure. Though protocols for measuring MP levels in marine or freshwater has been well developed, the conditions experienced by household plastic products can vary widely. Many plastic products are exposed to frequent high temperatures (up to 100 °C) and are cooled back to room temperature during daily use. It is therefore crucial to develop a sampling protocol that mimics the actual daily-use scenario for each particular product. This study focused on widely used polypropylene-based baby feeding bottles to develop a cost-effective protocol for MP release studies of many plastic products. The protocol developed here enables: 1) prevention of the potential contamination during sampling and detection; 2) realistic implementation of daily-use scenarios and accurate collection of the MPs released from baby feeding bottles based on WHO guidelines; and 3) cost-effective chemical determination and physical topography mapping of MPs released from baby feeding bottles. Based on this protocol, the recovery percentage using standard polystyrene MP (diameter of 2 µm) was 92.4-101.2% while the detected size was around 102.2% of the designed size. The protocol detailed here provides a reliable and cost-effective method for MP sample preparation and detection, which can substantially benefit future studies of MP release from plastic products.


Assuntos
Microplásticos , Poluentes Químicos da Água , Monitoramento Ambiental , Humanos , Lactente , Plásticos , Polipropilenos , Poliestirenos , Poluentes Químicos da Água/análise
6.
Front Plant Sci ; 12: 643579, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34149748

RESUMO

Along with being important pigments that determining the flower color in many plants, anthocyanins also perform crucial functions that attract pollinators and reduce abiotic stresses. Purple and white are two different colors of radish petals. In this study, two cDNA libraries constructed with purple and white petal plants were sequenced for transcriptome profiling. Transcriptome results implied that the expression level of the genes participating in the anthocyanin biosynthetic pathway was commonly higher in the purple petals than that in the white petals. In particular, two genes, F3'H and DFR, had a significantly higher expression pattern in the purple petals, suggesting the important roles these genes playing in radish petal coloration. BSA-seq aided-Next Generation Sequencing of two DNA pools revealed that the radish purple petal gene (RsPP) was located on chromosome 7. With additional genotyping of 617 F2 population plants, the RsPP was further confined within a region of 93.23 kb. Transcriptome and Sanger sequencing analysis further helped identify the target gene, Rs392880. Rs392880 is a homologous gene to F3'H, a key gene in the anthocyanin biosynthetic pathway. These results will aid in elucidating the molecular mechanism of plant petal coloration and developing strategies to modify flower color through genetic transformation.

7.
Artigo em Inglês | MEDLINE | ID: mdl-33799795

RESUMO

Previous studies investigating the effect of excessive weight on the foot have commonly been cross-sectional; therefore, it is still unclear how the foot function gradually changes with the increased body mass that is physiologically gained over time. This study aimed to use a load transfer method to identify the mechanism of how the foot function changed with the increased excessive body mass over two years. Taking normal weight as the baseline, fifteen children became overweight or obese (group 1), and fifteen counterparts maintained normal weight (group 0) over the two years. Barefoot walking was assessed using a Footscan® plate system. A load transfer method was used based upon the relative force-time integral (FTI) to provide an insight into plantar load transference as children increased in weight. Significantly increased FTIs were found at the big toe (BT), medial metatarsal (MM), lateral metatarsal (LM), and lateral heel (HL) in group 1, while at BT, MM, medial heel (HM), and HL in group 0. Foot load showed a posterior to anterior transferal from midfoot (2.5%) and heel (7.0%) to metatarsal and big toe in group 1. The control group, however, shifted the loading within the metatarsal level from LM to HM (4.1%), and equally relieved weight from around the midfoot (MF) (3.0%) to BT, MM, HM and HL. Earlier weight loss intervention is required to prevent further adverse effects on foot functions caused by excessive weight-bearing.


Assuntos
, Caminhada , Criança , Estudos Transversais , Humanos , Estudos Longitudinais , Pressão
8.
Angew Chem Int Ed Engl ; 60(14): 7845-7850, 2021 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-33645907

RESUMO

Dianionic hyponitrite (N2 O2 2- ) is often proposed, based on model complexes, as the key intermediate in reductive coupling of nitric oxide to nitrous oxide at the bimetallic active sites of heme-copper oxidases and nitric oxide reductases. In this work, we examine the gas-solid reaction of nitric oxide with the metal-organic framework CuI -ZrTpmC* with a suite of in situ spectroscopies and density functional theory simulations, and identify an unusual chelating N2 O2 .- intermediate. These results highlight the advantage provided by site-isolation in metal-organic frameworks (MOFs) for studying important reaction intermediates, and provide a mechanistic scenario compatible with the proposed one-electron couple in these enzymes.

9.
Biomed Res Int ; 2021: 8899699, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33628828

RESUMO

The in vivo characterization of the passive mechanical properties of the human triceps surae musculotendinous unit is important for gaining a deeper understanding of the interactive responses of the tendon and muscle tissues to loading during passive stretching. This study sought to quantify a comprehensive set of passive muscle-tendon properties such as slack length, stiffness, and the stress-strain relationship using a combination of ultrasound imaging and a three-dimensional motion capture system in healthy adults. By measuring tendon length, the cross-section areas of the Achilles tendon subcompartments (i.e., medial gastrocnemius and soleus aspects), and the ankle torque simultaneously, the mechanical properties of each individual compartment can be specifically identified. We found that the medial gastrocnemius (GM) and soleus (SOL) aspects of the Achilles tendon have similar mechanical properties in terms of slack angle (GM: -10.96° ± 3.48°; SOL: -8.50° ± 4.03°), moment arm at 0° of ankle angle (GM: 30.35 ± 6.42 mm; SOL: 31.39 ± 6.42 mm), and stiffness (GM: 23.18 ± 13.46 Nmm-1; SOL: 31.57 ± 13.26 Nmm-1). However, maximal tendon stress in the GM was significantly less than that in SOL (GM: 2.96 ± 1.50 MPa; SOL: 4.90 ± 1.88 MPa, p = 0.024), largely due to the higher passive force observed in the soleus compartment (GM: 99.89 ± 39.50 N; SOL: 174.59 ± 79.54 N, p = 0.020). Moreover, the tendon contributed to more than half of the total muscle-tendon unit lengthening during the passive stretch. This unequal passive stress between the medial gastrocnemius and the soleus tendon might contribute to the asymmetrical loading and deformation of the Achilles tendon during motion reported in the literature. Such information is relevant to understanding the Achilles tendon function and loading profile in pathological populations in the future.


Assuntos
Tendão do Calcâneo/fisiologia , Fenômenos Biomecânicos/fisiologia , Músculo Esquelético/fisiologia , Adulto , Articulação do Tornozelo/fisiologia , Eletromiografia , Feminino , Humanos , Masculino , Amplitude de Movimento Articular/fisiologia , Torque
10.
Nat Mater ; 20(2): 222-228, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33230325

RESUMO

Electrically conducting 2D metal-organic frameworks (MOFs) have attracted considerable interest, as their hexagonal 2D lattices mimic graphite and other 2D van der Waals stacked materials. However, understanding their intrinsic properties remains a challenge because their crystals are too small or of too poor quality for crystal structure determination. Here, we report atomically precise structures of a family of 2D π-conjugated MOFs derived from large single crystals of sizes up to 200 µm, allowing atomic-resolution analysis by a battery of high-resolution diffraction techniques. A designed ligand core rebalances the in-plane and out-of-plane interactions that define anisotropic crystal growth. We report two crystal structure types exhibiting analogous 2D honeycomb-like sheets but distinct packing modes and pore contents. Single-crystal electrical transport measurements distinctively demonstrate anisotropic transport normal and parallel to the π-conjugated sheets, revealing a clear correlation between absolute conductivity and the nature of the metal cation and 2D sheet packing motif.

11.
Hortic Res ; 7(1): 202, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33328451

RESUMO

Plant height is one of the most important agronomic traits that directly determines plant architecture, and compact or dwarf plants can allow for increased planting density and land utilization as well as increased lodging resistance and economic yield. At least four dwarf/semidwarf genes have been identified in different melon varieties, but none of them have been cloned, and little is known about the molecular mechanisms underlying internode elongation in melon. Here, we report map-based cloning and functional characterization of the first semidwarf gene short internode (Cmsi) in melon, which encodes an ERECTA-like receptor kinase regulating internode elongation. Spatial-temporal expression analyses revealed that CmSI exhibited high expression in the vascular bundle of the main stem during internode elongation. The expression level of CmSI was positively correlated with stem length in the different melon varieties examined. Ectopic expression of CmSI in Arabidopsis and cucumber suggested CmSI as a positive regulator of internode elongation in both species. Phytohormone quantitation and transcriptome analysis showed that the auxin content and the expression levels of a number of genes involved in the auxin signaling pathway were altered in the semidwarf mutant, including several well-known auxin transporters, such as members of the ABCB family and PIN-FORMED genes. A melon polar auxin transport protein CmPIN2 was identified by protein-protein interaction assay as physically interacting with CmSI to modulate auxin signaling. Thus, CmSI functions in an auxin-dependent regulatory pathway to control internode elongation in melon. Our findings revealed that the ERECTA family gene CmSI regulates stem elongation in melon through auxin signaling, which can directly affect polar auxin transport.

12.
Plant Sci ; 300: 110636, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33180714

RESUMO

Cucumber fruit wart composed of tubercule and spine (trichome on fruit) is not only an important fruit quality trait in cucumber production, but also a well-studied model for plant cell-fate determination. The development of spine is closely related to the initiation and formation of tubercule. The spine differentiation regulator CsGL1 has been proved to be epistatic to the tubercule initiation factor CsTu, which is the only connection to be identified between spine and tubercule formations. Our previous studies found that the MIXTA-LIKE transcription factor CsMYB6 can suppress fruit spine initiation, which is independent of CsGL1. How the formation of spine and tubercule is regulated at the molecular level by CsMYB6 remains poorly understood. In this study, we characterized cucumber 35S:CsMYB6 transgenic plants, which displayed an obvious reduction in the number and size of fruit spines and tubecules. Molecular analyses showed that CsMYB6 directly interacted with the key spine formation factor CsTTG1 in regulating the formation of fruit spine, and CsTu in regulating the initiation of fruit tubercule, respectively. Based on these evidences, a novel regulatory network is proposed by which CsMYB6/CsTTG1 and CsMYB6/CsTu complexes play an important role in regulating epidermal development, including spine formation and tubercule initiation in cucumber.


Assuntos
Cucumis sativus/anatomia & histologia , Cucumis sativus/crescimento & desenvolvimento , Cucumis sativus/genética , Frutas/anatomia & histologia , Frutas/crescimento & desenvolvimento , Frutas/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Fatores de Transcrição/genética , Tricomas/anatomia & histologia , Tricomas/genética , Tricomas/crescimento & desenvolvimento
13.
ACS Appl Mater Interfaces ; 12(41): 46710-46718, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-32965096

RESUMO

Due to spontaneous organization of cellulose nanocrystals (CNCs) into the chiral nematic structure that can selectively reflect circularly polarized light within a visible-light region, fabricating stretching deformation-responsive CNC materials is of great interest but is still a big challenge, despite such a function widely observed from existing creatures, like a chameleon, because of the inherent brittleness. Here, a flexible network structure is introduced in CNCs, exerting a bridge effect for the rigid nanomaterials. The as-prepared films display high flexibility with a fracture strain of up to 39%. Notably, stretching-induced structural color changes visible to the naked eye are realized, for the first time, for CNC materials. In addition, the soft materials show humidity- and compression-responsive properties in terms of changing apparent structural colors. Colored marks left by ink-free writing can be shown or hidden by controlling the environmental humidities. This biobased photonic film, acting as a new "smart skin", is potentially used with multifunctions of chromogenic sensing, encryption, and anti-counterfeit.

14.
Artigo em Inglês | MEDLINE | ID: mdl-32927864

RESUMO

Age is a key factor in plantar pressure distributions during the development of obese children. However, the existing evidence for age-related plantar pressures of obese children is not sufficient to make clear how the plantar pressures would change with the increasing age. This study aimed to evaluate the plantar pressure redistributions of obese children after a three-year follow-up and to further compare these changes with normal-weighted children. Ten obese children and eleven normal-weighted counterparts were involved in this study. Plantar pressure measurements were undertaken using a Footscan® plantar pressure plate on two test sessions three years apart. Peak pressure, pressure-time integral, standard maximum force, and z-scores of these variables were analyzed. Loading transference analyses were applied to detect the different loading transferring mechanisms between obese and normal-weighted children. Significantly increased plantar pressures were observed at the lateral forefoot and midfoot for obese children, which gradually deviated from those of normal-weighted children over the 3 years. With the increasing age, obese children displayed a lateral loading shift at the forefoot in contrast to the normal-weighted. Early interventions are cautiously recommended for obese children before the plantar loading deviation gets worse as they grow older.


Assuntos
Pé/anatomia & histologia , Pé/patologia , Obesidade/complicações , Pressão , Fenômenos Biomecânicos , Índice de Massa Corporal , Peso Corporal/fisiologia , Criança , China , Seguimentos , Humanos
15.
Shanghai Kou Qiang Yi Xue ; 29(1): 85-88, 2020 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-32524128

RESUMO

PURPOSE: To investigate the category and prevalence rate of denture-related oral mucosal lesions (DML) in 185 patients with removable denture and analyze the influencing factors. METHODS: A total of 185 patients with removable denture who visited the department of stomatology of our hospital from October 2015 to June 2018 were investigated by questionnaire. DML types and locations were recorded in detail, and patients were followed up after treatment. Based on the data of this study, the differences of DML reports in other regions of China were analyzed by comparing the results searched from databases. SPSS 17.0 software package was used for statistical analysis. RESULTS: In this study, the DML prevalence rate was 42.7%, significantly higher in male patients than in female patients (54.17% vs 35.40%, P<0.05). DML was more common in complete denture wearers than that in partial denture wearers (66.67% vs 31.20%, P<0.05). The categories of DML were as followed (prevalence rate from high to low): denture stomatitis (54.43%), traumatic ulcer (34.18%), inflammatory hyperplasia (6.33%), and angular cheilitis (5.06%). CONCLUSIONS: DML is affected by multiple factors. Among them, denture related factors include denture type, denture wearing time, denture lasting time and cleaning method. DML is more influenced by the type of denture than the wearing time. Gender, ethnicity and systemic diseases may affect the prevalence of DML, but further studies are needed. The results of domestic studies in various regions cannot objectively reflect the current prevalence rate of DML, thus a multi-center epidemiological investigation is needed.


Assuntos
Prótese Parcial Removível , Doenças da Boca , Estomatite sob Prótese , China , Prótese Total , Prótese Parcial , Feminino , Humanos , Masculino
16.
J Am Chem Soc ; 142(28): 12367-12373, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32532157

RESUMO

We report on the continuous fine-scale tuning of band gaps over 0.4 eV and of the electrical conductivity of over 4 orders of magnitude in a series of highly crystalline binary alloys of two-dimensional electrically conducting metal-organic frameworks M3(HITP)2 (M = Co, Ni, Cu; HITP = 2,3,6,7,10,11-hexaiminotriphenylene). The isostructurality in the M3(HITP)2 series permits the direct synthesis of binary alloys (MxM'3-x)(HITP)2 (MM' = CuNi, CoNi, and CoCu) with metal compositions precisely controlled by precursor ratios. We attribute the continuous tuning of both band gaps and electrical conductivity to changes in free-carrier concentrations and to subtle differences in the interlayer displacement or spacing, both of which are defined by metal substitution. The activation energy of (CoxNi3-x)(HITP)2 alloys scales inversely with an increasing Ni percentage, confirming thermally activated bulk transport.

17.
Gait Posture ; 80: 7-13, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32464538

RESUMO

BACKGROUND: Flatfoot has a very high incidence of obese children. Functional parameters such as plantar pressures and center of pressure (COP) are sensitive to foot type. However, previous foot biomechanical studies of obese children rarely excluded the flatfoot as a prerequisite of the participants involved. RESEARCH QUESTION: This study aimed to determine whether it is essential to define flatfoot as a subject screening criterion in the foot biomechanical study for obese children. METHODS: Foot types were classified by arch index (AI). Totally 21 obese children with flatfoot (OF group) along with matched control groups of obese children with normal foot (ON group) and normal-weighted children with flatfoot (NF group) were selected from our database. Barefoot walking trails were conducted using Footscan® plate system. Peak force (PF), peak pressure (PP), pressure-time integral (PTI), contact area (CA) and COP data were recorded. Independent t-test and effect size were used to compare the data between the study group and the control groups. Intraclass correlation coefficient was used to measure the between-trail reliability for the dependent variables. RESULTS: In comparison with the OF group, an upward trend for PF, PP and PTI was found for the ON group, while an opposite tendency for the NF group. The OF group displayed a significant larger CA under the midfoot region than the NF group even if there is no significant difference for AI. The OF group displayed a more medial shift of COP progression compared to the ON group. But no significant differences were found for COP parameters between the OF group and the NF group. SIGNIFICANCE: This study provided substantial evidence to support that prospective foot biomechanical research on the obese group needs to identify the flatfoot as one of the subject screening criteria to carry out more reliable results without producing confounding effects.


Assuntos
Pé Chato/fisiopatologia , Pé/fisiopatologia , Obesidade Pediátrica/fisiopatologia , Pressão , Caminhada , Adolescente , Fenômenos Biomecânicos , Peso Corporal , Estudos de Casos e Controles , Criança , Feminino , Humanos , Masculino , Estudos Prospectivos , Reprodutibilidade dos Testes
18.
J Zhejiang Univ Sci B ; 21(5): 361-368, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32425001

RESUMO

Since its emergence in December 2019, corona virus disease 2019 (COVID-19) has impacted several countries, affecting more than 90 thousand patients and making it a global public threat. The routes of transmission are direct contact, and droplet and possible aerosol transmissions. Due to the unique nature of dentistry, most dental procedures generate significant amounts of droplets and aerosols, posing potential risks of infection transmission. Understanding the significance of aerosol transmission and its implications in dentistry can facilitate the identification and correction of negligence in daily dental practice. In addition to the standard precautions, some special precautions that should be implemented during an outbreak have been raised in this review.


Assuntos
Aerossóis , Infecções por Coronavirus/transmissão , Infecção Hospitalar/prevenção & controle , Odontologia , Controle de Infecções/métodos , Pneumonia Viral/transmissão , Betacoronavirus , COVID-19 , Infecções por Coronavirus/prevenção & controle , Higiene das Mãos , Humanos , Pandemias/prevenção & controle , Equipamento de Proteção Individual , Pneumonia Viral/prevenção & controle , SARS-CoV-2
19.
Angew Chem Int Ed Engl ; 59(44): 19623-19626, 2020 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-32343881

RESUMO

The extension of reticular chemistry concepts to electrically conductive three-dimensional metal-organic frameworks (MOFs) has been challenging, particularly for cases in which strong interactions between electroactive linkers create the charge transport pathways. Here, we report the successful replacement of tetrathiafulvalene (TTF) with a nickel glyoximate core in a family of isostructural conductive MOFs with Mn2+ , Zn2+ , and Cd2+ . Different coordination environments of the framework metals lead to variations in the linker stacking geometries and optical properties. Single-crystal conductivity data are consistent with charge transport along the linker stacking direction, with conductivity values only slightly lower than those reported for the analogous TTF materials. These results serve as a case study demonstrating how reticular chemistry design principles can be extended to conductive frameworks with significant intermolecular contacts.

20.
Angew Chem Int Ed Engl ; 59(24): 9773-9779, 2020 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-32160393

RESUMO

A molecular-level understanding of transport and adsorption mechanisms of electrolyte ions in nanoporous electrodes under applied potentials is essential to control the performance of double-layer capacitors. Here, in operando small-angle neutron scattering (SANS) is used to directly detect ion movements into the nanopores of a conductive metal-organic framework (MOF) electrode under operating conditions. Neutron-scattering data reveals that most of the void space within the MOF is accessible to the solvent. Upon the addition of the electrolyte sodium triflate (NaOTf), the ions are adsorbed on the outer surface of the protrusions to form a 30 Šlayer instead of entering the ionophobic pores in the absence of an applied charging potential. The changes in scattering intensity when potentials are applied suggests the ion rearrangement in the micropores following different mechanisms depending on the electrode polarization. These observations shed insights on ion electrosorption in electrode materials.

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