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1.
Nature ; 598(7879): 129-136, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34616068

RESUMO

The mammalian cerebrum performs high-level sensory perception, motor control and cognitive functions through highly specialized cortical and subcortical structures1. Recent surveys of mouse and human brains with single-cell transcriptomics2-6 and high-throughput imaging technologies7,8 have uncovered hundreds of neural cell types distributed in different brain regions, but the transcriptional regulatory programs that are responsible for the unique identity and function of each cell type remain unknown. Here we probe the accessible chromatin in more than 800,000 individual nuclei from 45 regions that span the adult mouse isocortex, olfactory bulb, hippocampus and cerebral nuclei, and use the resulting data to map the state of 491,818 candidate cis-regulatory DNA elements in 160 distinct cell types. We find high specificity of spatial distribution for not only excitatory neurons, but also most classes of inhibitory neurons and a subset of glial cell types. We characterize the gene regulatory sequences associated with the regional specificity within these cell types. We further link a considerable fraction of the cis-regulatory elements to putative target genes expressed in diverse cerebral cell types and predict transcriptional regulators that are involved in a broad spectrum of molecular and cellular pathways in different neuronal and glial cell populations. Our results provide a foundation for comprehensive analysis of gene regulatory programs of the mammalian brain and assist in the interpretation of noncoding risk variants associated with various neurological diseases and traits in humans.

2.
Artigo em Inglês | MEDLINE | ID: mdl-34637383

RESUMO

Graph convolutional networks (GCNs) have achieved great success in many applications and have caught significant attention in both academic and industrial domains. However, repeatedly employing graph convolutional layers would render the node embeddings indistinguishable. For the sake of avoiding oversmoothing, most GCN-based models are restricted in a shallow architecture. Therefore, the expressive power of these models is insufficient since they ignore information beyond local neighborhoods. Furthermore, existing methods either do not consider the semantics from high-order local structures or neglect the node homophily (i.e., node similarity), which severely limits the performance of the model. In this article, we take above problems into consideration and propose a novel Semantics and Homophily preserving Network Embedding (SHNE) model. In particular, SHNE leverages higher order connectivity patterns to capture structural semantics. To exploit node homophily, SHNE utilizes both structural and feature similarity to discover potential correlated neighbors for each node from the whole graph; thus, distant but informative nodes can also contribute to the model. Moreover, with the proposed dual-attention mechanisms, SHNE learns comprehensive embeddings with additional information from various semantic spaces. Furthermore, we also design a semantic regularizer to improve the quality of the combined representation. Extensive experiments demonstrate that SHNE outperforms state-of-the-art methods on benchmark datasets.

3.
Anal Chim Acta ; 1180: 338871, 2021 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-34538326

RESUMO

Terahertz (THz) waves have the advantages of being noninvasive and nonionizing because of their low radiation energy, so they have potential applications in the biomedical field, but thus far, those have been limited by the strong absorption in water and low detection sensitivity. Herein, we propose a reflective THz time-domain circular dichroism (CD) sensing system and a silicon subwavelength grating as the microstructure sensor to generate and detect the THz chiral polarization states, to realize quantitative detection of living cell numbers and qualitative identification of cell kinds in a liquid environment. Three kinds of hepatoma cell proliferation and inhibition with different concentrations of aspirin were measured by this sensing method, and the experimental results show that the sensitivities for CD resonance intensity and frequency shift can reach 3.44 dB mL/106 cells and 5.88 GHz mL/106 cells, respectively, and the minimum detection concentration is in the order of 104 cells/mL for THz detection in a liquid environment for the first time. This new THz sensing system and sensing method are expected to become a broadband, label-free, noncontact, real-time detection technology that can be used for quantitative detection and qualitative identification of cells or other active biochemical materials.


Assuntos
Neoplasias , Água , Dicroísmo Circular , Vibração
5.
Artigo em Inglês | MEDLINE | ID: mdl-34490489

RESUMO

Stormwater runoff samples were collected from five different land use sites (gas station, city road, campus, park, and residential) in a precipitation event on May 22nd, 2017, from a small suburban area (5 km × 2 km) of the city of Beijing, China. There were 72 types of semi-volatile organic compounds (SVOCs) found in these runoff samples, including 33 types of monocyclic aromatic hydrocarbons (MAHs), 22 types of polycyclic aromatic hydrocarbons (PAHs), 6 types of phthalate esters (PAEs), 9 types of pesticides and 2 types of polychlorinated biphenyls (PCBs). Especially, 26 types of SVOCs (7 MAHs, 9 PAHs, 5 PAEs, and 5 pesticides) were detected in all water samples. SVOCs concentrations were higher in the samples from gas station and city road, and lower in runoff from campus, park and residential sites. The change in the ratio of anthracene to anthracene plus phenanthrene (ANT/(ANT + PHE)) in this study, reflected the importance of PAH source and land use. Di-2-ethylhexyl phthalate (DEHP) and di-n-butyl phthalate, are two of the phthalate esters 100% detected in the runoff samples. The city road runoff DEHP concentrations recorded the highest values (> 6000 ng/L), however, were still less than those wastewater DEHP pollutants measured in developed countries (e.g. UK, Canada, Finland, etc.). One-way ANOVA analysis in this study, showed that land use could significantly influence 23 SVOCs in the runoff samples, whereas the runoff SVOCs in different precipitation period showed no statistical changes in the five sites, and presented a general temporal trends "high (beginning)-low (middle period)-little raising (ending)". The findings in this study could be used in municipal management of wastewater collection and treatment.

6.
Talanta ; 234: 122651, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34364460

RESUMO

Wide uses of azo dyes produce a great risk of high residuals of carcinogenic aromatic amines, and hence it is important to rapidly analyze these carcinogenic compounds in the textile products to guarantee product safety. In the present work, a surface enhanced Raman spectroscopic (SERS) method was developed for rapid detection of carcinogenic aromatic amines in textiles. In this method, target aromatic amines are extracted from textiles, and then gold nanoparticles are added to the organic extractant, which assemble into closely packed Au array at liquid interface in situ. Finally, fingerprint SERS signals of the target aromatic amines are detected on the generated Au array on the basis of strong chemical interaction between the aromatic amines and the Au surface. The proposed method provided good reproducibility with a relative standard deviation of 3.5% for ten parallel tests of benzidine. It was applied to analyze 70 textile products. To strengthen the spectroscopic data processing, a cluster analysis model was established with 50 samples to automatically identify the spectra based on the good signal reproducibility. The other 20 samples were used as test sets to validate this model. It was found that all the positive samples were successfully identified with false positive rate of 20%. With the addition of the Artificial Intelligence step, the reliability of the discriminant results can be ensured.


Assuntos
Ouro , Nanopartículas Metálicas , Aminas , Inteligência Artificial , Compostos Azo , Reprodutibilidade dos Testes , Análise Espectral Raman , Têxteis
7.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 35(7): 891-895, 2021 Jul 15.
Artigo em Chinês | MEDLINE | ID: mdl-34308599

RESUMO

Objective: To investigate the effectiveness of lateral circumflex femoral artery chimeric flap transplantation in repair of complex wounds of foot and ankle. Methods: A retrospective study was conducted to analyze the clinical data of 20 patients with complex wounds of foot and ankle treated with lateral circumflex femoral artery chimeric flap between June 2017 and June 2020. There were 14 males and 6 females with an average age of 42.8 years (range, 21-65 years). Among them, 8 cases had dorsalis pedis tendon defect with or without bone exposure, 4 cases had partial or total Achilles tendon defect without bone exposure, and 8 cases had deep cavity and bone exposure. The wound area ranged from 10 cm×6 cm to 21 cm×11 cm. The time from injury to operation ranged from 6 to 22 days, with an average of 9.4 days. The lateral femoral circumflex artery flap was used in 6 cases with fascia lata flap, 6 cases with rectus femoris aponeurosis flap, and 8 cases with lateral femoral muscle flap. The flap area ranged from 12.0 cm×6.5 cm to 35.0 cm×7.5 cm. All flap donor sites were sutured directly. The survival, appearance, texture, sensation of the flap, and complications of the donor site were observed. The foot and ankle function was evaluated by Kofoed score. Results: All patients were followed up 8-24 months (mean, 14.2 months). On the 3rd day after operation, 1 case had partial necrosis of 1 flap with fascia lata flap and healed after dressing change; 1 case of chimeric muscle flap developed venous crisis at 12 hours after operation; the chimeric flaps survived successfully in the other 18 patients and the wounds were primary healing. The color and texture of the flaps were good, the flaps recovered protective sensation. Only linear scar remained in the donor site of thigh. There was no sensory disturbance around the incision or walking disturbance. The Kofoed score of the foot and ankle function at last follow-up was 75-96, with an average of 89.8. Among them, 15 cases were excellent, 4 cases were good, and 1 case was qualified. The excellent and good rate was 95.0%. Conclusion: The application of lateral circumflex femoral artery chimeric flap can accurately and stereoscopically repair the complex wounds of foot and ankle and achieve satisfactory effectiveness.


Assuntos
Retalho Perfurante , Procedimentos Cirúrgicos Reconstrutivos , Lesões dos Tecidos Moles , Adulto , Tornozelo/cirurgia , Feminino , Artéria Femoral/cirurgia , Humanos , Masculino , Estudos Retrospectivos , Transplante de Pele , Lesões dos Tecidos Moles/cirurgia , Coxa da Perna , Resultado do Tratamento
8.
Nat Commun ; 12(1): 4407, 2021 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-34315870

RESUMO

Alcohol Use Disorder (AUD) affects a large portion of the population. Unfortunately, efficacious medications to treat the disease are limited. Studies in rodents suggest that mTORC1 plays a crucial role in mechanisms underlying phenotypes such as heavy alcohol intake, habit, and relapse. Thus, mTORC1 inhibitors, which are used in the clinic, are promising therapeutic agents to treat AUD. However, chronic inhibition of mTORC1 in the periphery produces undesirable side effects, which limit their potential use for the treatment of AUD. To overcome these limitations, we designed a binary drug strategy in which male mice were treated with the mTORC1 inhibitor RapaLink-1 together with a small molecule (RapaBlock) to protect mTORC1 activity in the periphery. We show that whereas RapaLink-1 administration blocked mTORC1 activation in the liver, RapaBlock abolished the inhibitory action of Rapalink-1. RapaBlock also prevented the adverse side effects produced by chronic inhibition of mTORC1. Importantly, co-administration of RapaLink-1 and RapaBlock inhibited alcohol-dependent mTORC1 activation in the nucleus accumbens and attenuated alcohol seeking and drinking.


Assuntos
Consumo de Bebidas Alcoólicas/patologia , Encéfalo/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/antagonistas & inibidores , Animais , Intolerância à Glucose/complicações , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos Endogâmicos C57BL , Núcleo Accumbens/efeitos dos fármacos , Núcleo Accumbens/metabolismo , Especificidade de Órgãos , Sirolimo/análogos & derivados , Sirolimo/farmacologia , Perda de Peso/efeitos dos fármacos
9.
Science ; 373(6554): 541-547, 2021 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-34326236

RESUMO

Repurposing drugs as treatments for COVID-19, the disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has drawn much attention. Beginning with sigma receptor ligands and expanding to other drugs from screening in the field, we became concerned that phospholipidosis was a shared mechanism underlying the antiviral activity of many repurposed drugs. For all of the 23 cationic amphiphilic drugs we tested, including hydroxychloroquine, azithromycin, amiodarone, and four others already in clinical trials, phospholipidosis was monotonically correlated with antiviral efficacy. Conversely, drugs active against the same targets that did not induce phospholipidosis were not antiviral. Phospholipidosis depends on the physicochemical properties of drugs and does not reflect specific target-based activities-rather, it may be considered a toxic confound in early drug discovery. Early detection of phospholipidosis could eliminate these artifacts, enabling a focus on molecules with therapeutic potential.


Assuntos
Antivirais/farmacologia , COVID-19/tratamento farmacológico , Reposicionamento de Medicamentos , Lipidoses/induzido quimicamente , Fosfolipídeos/metabolismo , SARS-CoV-2/efeitos dos fármacos , Células A549 , Animais , Antivirais/química , Antivirais/uso terapêutico , Antivirais/toxicidade , COVID-19/virologia , Cátions , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Feminino , Humanos , Camundongos , Testes de Sensibilidade Microbiana , SARS-CoV-2/fisiologia , Tensoativos/química , Tensoativos/farmacologia , Tensoativos/toxicidade , Células Vero , Replicação Viral/efeitos dos fármacos
10.
Se Pu ; 39(3): 229-240, 2021 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-34227305

RESUMO

Polymeric monolithic columns are fabricated by in situ polymerization of the corresponding monomer, crosslinkers, porogenic solvents and radical initiators within a mold. Compared with the conventional packed solid phase extraction adsorbents, polymeric monolithic columns with a continuous porous structure process distinctive advantages of rapid mass transfer and excellent permeability, which facilitates the extraction of trace amounts of the target from the matrix even at high flow velocities. Besides, these materials can be easily fabricated in situ within various cartridges, avoiding a further packing step associated with packed particulate adsorbents. Additionally, the abundant monomer availability, flexible porous structure, and wide applicable pH range make monoliths versatile for use in separation science. Thus, polymeric monolithic columns have been increasingly applied as efficient and promising extraction media for sample pretreatment food, pharmaceutical, biological and environmental analyses. However, these materials usually have the difficulty in morphology control and their interconnected porous micro-globular structure, which may result in low porosity, limited specific surface area and poor efficiency. In addition, polymeric monoliths suffer from the swelling in organic solvents, thus decreasing the service life and precision while increasing the cost consumption. Recently, the development of nanomaterial-incorporated polymeric monoliths with an improved ordered structure, enhanced adsorption efficiency and outstanding selectivity has attracted considerable attention. Nanoparticles are considered as particulates within the size range of 1-100 nm in at least one dimension, which endows them with unique optical, electrical and magnetic properties. These materials have a large surface area, excellent thermal and chemical stabilities, remarkable versatility, as well as a wide variety of active functional groups on their surface. With the aim of exploiting these advantages, researchers have shown great interest in applying nanomaterial-incorporated polymeric monoliths to separation science. Accordingly, significant progress has been achieved in this field. Nanomaterials can be entrapped via the direct synthesis of a polymerization solution that contains well dispersed nanomaterials in porogens. In addition, nanoparticles can be incorporated into the monolithic matrix by copolymerization and post-polymerization modification via specific interactions. Therefore, nanomaterial-incorporated polymeric monoliths combined the different shapes, chemical properties, and physical properties of the polymers with those of the nanoparticles. The presence of nanoparticles can improve the structural rigidity as well as the thermal and chemical stabilities of monolithic adsorbents. Besides, nanoparticles are capable of increasing the specific surface area and providing multiple active sites, which leads to enhanced extraction performance and selectivity of polymeric monolithic materials. In recent years, diverse types of nanomaterials, such as carbonaceous nanoparticles, metallic materials and metal oxides, metal-organic frameworks, covalent organic frameworks and inorganic nanoparticles have been extensively explored as hybrid adsorbents in the modes of solid phase extraction, solid phase microextraction, stir bar sorption extraction and on-line solid phase extraction. This review specifically summarizes the fabrication methods for nanomaterial incorporated polymeric monoliths and their application to the field of sample pretreatment. The existing challenges and future possible perspectives in the field are also discussed.

11.
Zootaxa ; 4975(1): 187192, 2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34186571

RESUMO

Two new species of the genus are described from Zhejiang, China in this paper. The new species Criotettix jinningensis sp. nov. is similar to Criotettix strivertexoides Zheng, Wei Li, 2009, but differs in width of vertex narrower than diameter of eye; pronotum shorter, not reaching the end of hind tibiae; width of fore wing 1.3 times width of mid leg femur and hind wing not reaching the end of pronotum. The new species Criotettix pananensis sp. nov. is similar to Criotettix transpi-noides Zheng, Bai Xu, 2012, it differs from latter by width of vertex narrower than diameter of eye; pronotum with parallel lateral keels and without a pair short longitudinal keels between shoulders; hind femur without projection in upper keel and hind wing extending over the end of pronotum. The type specimens are deposited in the College of Life Sciences, Hebei University, Baoding, China.


Assuntos
Ortópteros/anatomia & histologia , Ortópteros/classificação , Estruturas Animais , Animais , China
12.
Int J Nanomedicine ; 16: 3497-3508, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34045854

RESUMO

Purpose: The PML/RARα fusion gene as a leukemogenesis plays a significant role in clinical diagnosis of the early stage of acute promyelocytic leukemia (APL). Here, we present an electrochemical biosensor for PML/RARα fusion gene detection using carbon dots functionalized graphene oxide (CDs/GO) nanocomposites modified glassy carbon electrode (CDs/GO/GCE). Materials and Methods: In this work, the CDs/GO nanocomposites are produced through π-π stacking interaction and could be prepared in large quantities by a facile and economical way. The CDs/GO nanocomposites were decorated onto electrode surface to improve the electrochemical activity and as a bio-platform attracted the target deoxyribonucleic acid (DNA) probe simultaneously. Results: The CDs/GO/GCE was fabricated successfully and exhibits high electrochemical activity, good biocompatibility, and strong bioaffinity toward the target DNA sequences, compared with only the pristine CDs on GCE or GO on GCE. The DNA biosensor displays excellent sensing performance for detecting the relevant pathogenic DNA of APL with a detection limit of 83 pM (S/N = 3). Conclusion: According to the several experimental results, we believe that the simple and economical DNA biosensor has the potential to be an effective and powerful tool for detection of pathogenic genes in the clinical diagnosis.


Assuntos
Técnicas Biossensoriais/métodos , Carbono/química , DNA/genética , Fusão Gênica/genética , Grafite/química , Nanocompostos/química , Proteínas de Fusão Oncogênica/genética , Técnicas Biossensoriais/instrumentação , Eletroquímica , Eletrodos , Humanos
13.
Phys Chem Chem Phys ; 23(17): 10236-10243, 2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-33884399

RESUMO

Solid-acid catalysts functionalized with catalytic groups have attracted intense interest for converting cellulose into soluble products. However, design of solid-7 acid catalysts has been guided by molecular level interactions and the actual mechanism of cellulose-solid-acid catalyst particles adsorption remains unknown. Here, colloidal stability theory, DLVO, is used to rationalize the design of solid acids for targeted cellulose adsorption. In nearly all cases, an energy barrier, arising from electrostatic repulsion and much larger than the energy associated with thermal fluctuations, prevents close contact between the solid acid and cellulose. Polymer-based solid-acid substrates such as polystyrene and Nafion are especially ineffective as their interaction with cellulose is dominated by the repulsive electrostatic force. Carbon and metal oxides have potential to be effective for cellulose-solid-acid interaction as their attractive van der Waals interaction can offset the repulsive electrostatic interaction. The effects of reactor temperature and shear force were evaluated, with the finding that reactor temperature can minimize the catalyst-cellulose interaction barrier, promoting coagulation, but that the shear force in a typical laboratory reactor cannot. We have evaluated strategies for enhancing cellulose-catalyst interaction and conclude that raising reaction temperature or synthesizing acid/base bifunctional catalysts can effectively diminish electrostatic repulsion and promote cellulose-catalyst coagulation. The analysis presented here establishes a rational method for designing solid acid catalysts for cellulose hydrolysis.

14.
Small ; : e2008052, 2021 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-33887101

RESUMO

Hydrogenation of diesters to diols is a vital process for chemical industry. The inexpensive Cu+ /Cu0 -based catalysts are highly active for the hydrogenation of esters, however, how to efficiently tune the ratio of Cu+ /Cu0 and stabilize the Cu+ is a great challenge. In this work, it is demonstrated that doped Ti ions can tune the ratio of Cu+ /Cu0 and stabilize the Cu+ by the TiOCu bonds in Ti-doped SiO2 supported Cu nanoparticle (Cu/Ti-SiO2 ) catalysts for the high conversion of dimethyl adipate to 1,6-hexanediol. In the synthesis of the catalysts, the Ti4+ OCu2+ bonds promote the reduction of Cu2+ to Cu+ by forming Ti3+ OV Cu+ (OV : oxygen vacancy) bonds and the amount of Ti doping can tune the ratio of Cu+ /Cu0 . In the catalytic reaction, the O vacancy activates CO in the ester by forming new Ti3+ δ OR Cu1+ δ bonds (OR : reactant oxygen), and Cu0 activates hydrogen. After the products are desorbed, the Ti3+ δ OR Cu1+ δ bonds return to the initial state of Ti3+ OV Cu+ bonds. The reversible TiOCu bonds greatly improve the activity and stability of the Cu/Ti-SiO2 catalysts. When the content of Ti is controlled at 0.4 wt%, the conversion and selectivity can reach 100% and 98.8%, respectively, and remain stable for 260 h without performance degradation.

15.
Environ Sci Pollut Res Int ; 28(28): 37627-37635, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33715129

RESUMO

To reach discharge limit, further treatment of bio-treated leachate from Chinese herbal medicine residue (BLCHMR) was very imperative. In this study, performance of combined coagulation/decantation-ozone/hydrogen peroxide (O3/H2O2)-biological aerated filter (BAF) technology used to further treat BLCHMR was investigated with pilot-scale experiment. Under optimal conditions, the COD (40-44 mg/L) and color (13-17 time) in treated BLCHMR indicated that combined process can efficiently treat BLCHMR. O3/H2O2 had good performance not only in mineralization and decomposing of organic matter but also in decolorization of BLCHMR. For dissolved organic matter (DOM), O3/H2O2 reacted with non-biodegradable fraction preferentially and oxidized different molecular weight (MW) fractions equally. O3/H2O2-BAF generated more higher MW DOM (namely F2 fraction) than BAF alone. Meanwhile, O3/H2O2 mainly influenced the amount and biodegradability on DOM but not the removal rate on DOM. Accordingly, the helpful influence on O3/H2O2 perhaps can be owed to the generalized influence on DOM but not the specific influence on improved biodegradability. Finally, inspiring (namely very low) cost (respectively, 0.3419 $/per ton bio-treated leachate and 0.5766 $/Kg COD removed) was achieved in the combined process.


Assuntos
Medicamentos de Ervas Chinesas , Ozônio , Poluentes Químicos da Água , Peróxido de Hidrogênio , Oxirredução , Poluentes Químicos da Água/análise
16.
Int J Biol Macromol ; 179: 136-143, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33667555

RESUMO

Scalloped (Sd) is transcription factor that regulates cell proliferation and organ growth in the Hippo pathway. In the present research, LmSd was identified and characterized, and found to encode an N-terminal TEA domain and a C-terminal YBD domain. qRT-PCR showed that the LmSd transcription level was highest in the fifth-instar nymphs and very little was expressed in embryos. Tissue-specific analyses showed that LmSd was highly expressed in the wing. Immunohistochemistry indicated that LmSd was highly abundant in the head, prothorax, and legs during embryonic development. LmSd dsRNA injection resulted in significantly down-regulated transcription and protein expression levels compared with dsGFP injection. Gene silencing of LmSd resulted in deformed wings that were curved, wrinkled, and failed to fully expand. Approximately 40% of the nymphs had wing pads that were not able to close normally during molting from fifth-instar nymphs into adults. After silencing of LmSd, the transcription levels of cell division genes were suppressed and the expression levels of apoptosis genes were significantly up-regulated. Our results reveal that LmSd plays an important role in wing formation and development by controlling cell proliferation and inhibiting apoptosis.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Locusta migratoria , Transdução de Sinais , Fatores de Transcrição , Animais , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Locusta migratoria/embriologia , Locusta migratoria/genética , Ninfa/genética , Ninfa/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
17.
J Am Chem Soc ; 2021 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-33724014

RESUMO

The bottom-up assembly of periodically ordered structures provides a scalable way for producing metastructured materials with exotic optical and mechanical properties. However, direct self-assembly of small molecules into such metastructures beyond the nanoscale remains an unresolved issue. Here we demonstrate that metastructured assemblies of two-dimensional (2D) polymers, specifically 2D covalent organic frameworks (COFs), can be directly synthesized in solution. We applied 2D COF monomer polycondensation to prepare flower-shaped particles consisting of highly crystalline "petals" with sizes larger than 20 µm. The petal comprises periodically arranged COF nanoflake units with tunable lengths of 490-850 nm, thicknesses about 20 nm, interflake spacing around 14 nm, and Hermans orientation factors up to 0.998. Such a metastructure is mechanically robust and remains almost intact even after full pyrolysis at 900 °C. It also demonstrates unique birefringence and polarization-dependent resonances under visible-near-infrared light not observed in its constituents, 2D COF polycrystals, and with well-defined nanopores of 1.8 nm and the high surface area of 1576 m2/g. Such metastructured particles with nanopores are well-suited as novel particulate optical devices for collecting and storing information about their surroundings that can be easily read out by polarization imaging with high sensitivity, as demonstrated by their explosive detection and anticounterfeiting applications. Self-assembly of 2D polymers into metastructures may become an important method for developing functional materials with unprecedented properties and extensive applications.

18.
Arthroscopy ; 37(6): 1872-1880, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33539975

RESUMO

PURPOSE: This study aimed to evaluate the clinical outcomes for arthroscopic treatment for acute posterior cruciate ligament (PCL) avulsion fractures with a suspensory technique. METHODS: A total of 30 acute (<3 weeks) isolated PCL tibial avulsion fractures were fixed under arthroscopy using the Endobutton device. After arthroscopic exploration and reduction of the bony fragment, a single tibia tunnel was established; then, the titanium button was guided through the tunnel and flipped onto the bony fragment to stabilize the fracture. Finally, an interference screw was squeezed into the tunnel to fix the end of the loop. Clinical and functional outcomes were evaluated using the Lysholm score, the 2000 International Knee Documentation Committee (IKDC) subjective score, and the IKDC examination form. RESULTS: The mean follow-up time was 32 months (range, 24-47 months). The mean age of the patients was 41 years (range, 21-65 years). All patients achieved bony union and regained satisfactory knee function. No popliteal neurovascular complications or implant loosening was observed. The mean Lysholm score increased from 20.9 ± 7.0 before operation to 97.1 ± 2.7 at the final follow-up. The mean 2000 IKDC subjective score improved from 17.2 ± 5.2 to 96.8 ± 2.6. The IKDC examination grade also improved significantly. CONCLUSIONS: This suspensory technique under arthroscopy is a simple, safe, and minimally invasive treatment for PCL tibial avulsion fracture. Suspensory fixation resulted in satisfactory outcomes, including good knee stability and fracture union; this technique can be a reliable alternative to various surgical methods. LEVEL OF EVIDENCE: Level IV, therapeutic study.


Assuntos
Fratura Avulsão , Ligamento Cruzado Posterior , Fraturas da Tíbia , Adulto , Idoso , Artroscopia , Fratura Avulsão/cirurgia , Humanos , Articulação do Joelho/cirurgia , Pessoa de Meia-Idade , Ligamento Cruzado Posterior/cirurgia , Técnicas de Sutura , Fraturas da Tíbia/cirurgia , Resultado do Tratamento , Adulto Jovem
19.
Ann Biomed Eng ; 49(7): 1688-1700, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33417054

RESUMO

Cannulation is not only one of the most common medical procedures but also fraught with complications. The skill of the clinician performing cannulation directly impacts cannulation outcomes. However, current methods of teaching this skill are deficient, relying on subjective demonstrations and unrealistic manikins that have limited utility for skills training. Furthermore, of the factors that hinders effective continuing medical education is the assumption that clinical experience results in expertise. In this work, we examine if objective metrics acquired from a novel cannulation simulator are able to distinguish between experienced clinicians and established experts, enabling the measurement of true expertise. Twenty-two healthcare professionals, who practiced cannulation with varying experience, performed a simulated arteriovenous fistula cannulation task on the simulator. Four clinicians were peer-identified as experts while the others were designated to the experienced group. The simulator tracked the motion of the needle (via an electromagnetic sensor), rendered blood flashback function (via an infrared light sensor), and recorded pinch forces exerted on the needle (via force sensing elements). Metrics were computed based on motion, force, and other sensor data. Results indicated that, with near 80% of accuracy using both logistic regression and linear discriminant analysis, the objective metrics differentiated between experts and the experienced, including identifying needle motion and finger force as two prominent features that distinguished between the groups. Furthermore, results indicated that expertise was not correlated with years of experience, validating the central hypothesis of the study. These insights contribute to structured and standardized medical skills training by enabling a meaningful definition of expertise and could potentially lead to more effective skills training methods.

20.
bioRxiv ; 2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33501437

RESUMO

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in millions of deaths worldwide and massive societal and economic burden. Recently, a new variant of SARS-CoV-2, known as B.1.1.7, was first detected in the United Kingdom and is spreading in several other countries, heightening public health concern and raising questions as to the resulting effectiveness of vaccines and therapeutic interventions. We and others previously identified host-directed therapies with antiviral efficacy against SARS-CoV-2 infection. Less prone to the development of therapy resistance, host-directed drugs represent promising therapeutic options to combat emerging viral variants as host genes possess a lower propensity to mutate compared to viral genes. Here, in the first study of the full-length B.1.1.7 variant virus , we find two host-directed drugs, plitidepsin (aplidin; inhibits translation elongation factor eEF1A) and ralimetinib (inhibits p38 MAP kinase cascade), as well as remdesivir, to possess similar antiviral activity against both the early-lineage SARS-CoV-2 and the B.1.1.7 variant, evaluated in both human gastrointestinal and lung epithelial cell lines. We find that plitidepsin is over an order of magnitude more potent than remdesivir against both viruses. These results highlight the importance of continued development of host-directed therapeutics to combat current and future coronavirus variant outbreaks.

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