Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 62
Filtrar
1.
Chemosphere ; 362: 142597, 2024 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-38889873

RESUMO

In the past decades, the amount of biomass waste has continuously increased in human living environments, and it has attracted more and more attention. Biomass is regarded as the most high-quality and cost-effective precursor material for the preparation carbon of adsorbents and catalysts. The application of biomass carbon has extensively explored. The efficient application of biomass carbon in organic wastewater purification were reviewed. With briefly introducing biomass types, the latest progress of Machine learning in guiding the preparation and application of biomass carbon was emphasized. The key factors in constructing efficient biomass carbon for adsorption and catalytic applications were discussed. Based on the functional groups, rich pore structure and active site of biomass carbon, it exhibits high efficiency in water purification performance in the fields of adsorption and catalysis. In addition, out of a firm belief in the enormous potential of biomass carbon, the remaining challenges and future research directions were discussed.

2.
Fitoterapia ; 176: 105976, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38685511

RESUMO

Phytochemical research on an extract of Notopterygium incisum yielded fifteen compounds (1-15), including four previously undescribed compounds (10-13). The structures of the unreported compounds were elucidated by spectroscopic and spectrometric data analysis such as 1D and 2D NMR, IR and HR-ESI-MS. Compounds 1-5 and 10-14 were isolated from N. incisum for the first time. 7S⁎,8R⁎-Phenethyl-(7-methoxy-8-isoeugenol)-ferulate (10), 7S⁎,8R⁎-p-hydroxyphenethyl-(7-methoxy-8-isoeugenol)-ferulate (11), 7S⁎,8R⁎-benzyl-(7-methoxy-8-isoeugenol)-ferulate (12) and p-hydroxyphenethyl-(4-benzoy-3-methoxy)-cinnamate (13) are the undescribed ferulic acid derivatives. Additionly, the anti-neuroinflammatory effects of compounds were evaluated in lipopolysaccharide (LPS)-induced BV2 cells. The pharmacological results showed that 6ß,10ß-epoxy-4α-hydroxy-guaiane (6), teuclatriol (7) and 7S⁎,8R⁎-p-hydroxyphenethyl-(7-methoxy-8-isoeugenol)-ferulate (11) inhibited the production and expression of nitric oxide (NO) in the LPS-induced BV2 cells in a concentration-dependent manner. Acorusnol (4), teucladiol (9), 7S⁎,8R⁎-benzyl-(7-methoxy-8-isoeugenol)-ferulate (12) and p-hydroxyphenethyl-(4-benzoy-3-methoxy)-cinnamate (13) only inhibited the release of NO at concentration of 20 µM. Moreover, 7S⁎,8R⁎-p-hydroxyphenethyl-(7-methoxy-8-isoeugenol)-ferulate (11) reduced the level of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in LPS-stimulated BV2 cells. The results demonstrated 7S⁎,8R⁎-p-hydroxyphenethyl-(7-methoxy-8-isoeugenol)-ferulate (11) could be a potential anti-neuroinflammatory agent and is worthy of further study.


Assuntos
Anti-Inflamatórios , Apiaceae , Compostos Fitoquímicos , Camundongos , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/isolamento & purificação , Estrutura Molecular , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/isolamento & purificação , Apiaceae/química , Linhagem Celular , Óxido Nítrico/metabolismo , China , Microglia/efeitos dos fármacos , Extratos Vegetais/farmacologia , Extratos Vegetais/química
3.
Inorg Chem ; 63(14): 6500-6513, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38532637

RESUMO

It is a challenging task to design a piezoelectric photocatalyst with excellent performance under mechanical agitation instead of ultrasonic irradiation. Integrating vacancy defects into a heterojunction seems to be an effective strategy for synergistically increasing its piezo-photocatalytic performance. For this goal, a two-step hydrothermal method was adopted to architect a type-I oxygen-vacancy-rich BaTiO3/BiOBr heterojunction to surge the degradation of Rhodamine B (RhB) under the combined action of simulated sunlight irradiation and mechanical agitation. Various instrumental techniques demonstrated the formation of a BaTiO3/BiOBr heterojunction with high crystallinity. The existence of surface oxygen vacancies was confirmed by XPS and EPR tests. PFM results manifested that this heterojunction had excellent piezoelectric properties, with a piezoelectric response value of 30.31 pm V-1. Comparative experiments indicated that RhB degradation efficiency under piezo-photocatalysis over this heterojunction largely exceeded the total sum of those under piezocatalysis and photocatalysis. h+, ·O2-, and 1O2 were the dominant reactive species for RhB degradation. The improved separation efficiency of photogenerated charges was verified by electrochemical measurements. DFT calculations indicated that the polarization of BaTiO3 could affect the electronic band structure of BiOBr. This work will provide comprehensive insights into piezo-photocatalytic mechanism at a microcosmic level and help to develop new-styled piezoelectric photocatalysts.

4.
Inorg Chem ; 63(9): 4447-4460, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38385361

RESUMO

Photocatalytic coupling technologies have emerged as popular strategies to increase the treatment efficiency of dye-containing wastewater. Herein, the Z-scheme Co3O4/BiOBr heterojunction (Z-CBH) was constructed and developed as a photocatalytic peroxydisulfate (PDS) activator for the degradation of high-concentration Rhodamine B (RhB). Multiple testing techniques were employed to confirm the formation of Z-CBHs. When 0.1 g·L-1 of Z-CBH20 and 1.0 mmol·L-1 of PDS were added simultaneously under simulated sunlight irradiation, the RhB degradation efficiency could approach 91.3%. Its reaction rate constant (0.01231 min-1) was much beyond the sum of those in the Z-CBH20/light system (0.00436 min-1) and the PDS/light system (0.0062 min-1). h+, •OH, •O2-, SO4•-, and 1O2 were detected as the dominant reactive species for RhB degradation. The potential mechanism of photocatalytic PDS oxidation was proposed. The possible intermediates were determined by high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry assisted with density functional theory and Fukui theory. The possible degradation pathways of RhB degradation were put forward. The toxicological properties of RhB and its intermediates were evaluated by quantitative structure-activity relationship prediction. This work will not only provide a reference for developing photocatalytic persulfate activators but also gain an insight into the degradation pathways of RhB and the toxicity of its intermediates.

5.
J Appl Clin Med Phys ; 25(3): e14195, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37915300

RESUMO

OBJECTIVE: Surface-guided radiation therapy (SGRT, AlignRT) was used to analyze motion during stereotactic body radiotherapy (SBRT) in lung cancer patients and to explore the margin of the planning target volume (PTV). METHODS: The residual errors of the AlignRT were evaluated based on grayscale cone-beam computed tomography registration results before each treatment. AlignRT log file was used to analyze the correlation between the frequency and longest duration of errors larger than 2 mm and lasting longer than 2 s and maximum error with age and treatment duration. The displacement value at the end of treatment, the average displacement value, and the 95% probability density displacement interval were defined as intrafraction errors, and PTV1, PTV2, PTV3 were calculated by Van Herk formula or Z score analysis. Organ dosimetric differences were compared after the experience-based margin was replaced with PTV3. RESULTS: The interfraction residual errors were Vrt0 , 0.06 ± 0.18 cm; Lng0 , -0.03 ± 0.19 cm; Lat0 , 0.02 ± 0.15 cm; Pitch0 , 0.23 ± 0.7°; Roll0 , 0.1 ± 0.69°; Rtn0 , -0.02 ± 0.79°. The frequency, longest duration and maximum error in vertical direction were correlated with treatment duration (r = 0.404, 0.353, 0.283, p < 0.05, respectively). In the longitudinal direction, the frequency was correlated with age and treatment duration (r = 0.376, 0.283, p < 0.05, respectively), maximum error was correlated with age (r = 0.4, P < 0.05). Vertical, longitudinal, lateral margins of PTV1, PTV2, PTV3 were 2 mm, 4 mm, 2 mm; 2 mm, 2 mm, 2 mm, 3 mm, 5 mm, 3 mm, respectively. After replacing the original PTV, mean lung dose (MLD), 2-cm3 chest wall dose (CD), lung V20 decreased by 0.2 Gy, 2.1 Gy, 0.5%, respectively (p < 0.05). CONCLUSION: AlignRT can be used for interfraction setup and monitoring intrafraction motion. It is more reasonable to use upper and lower limits of the 95% probability density interval as an intrafraction error.


Assuntos
Neoplasias Pulmonares , Radiocirurgia , Radioterapia Guiada por Imagem , Humanos , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/cirurgia , Radiocirurgia/métodos , Radioterapia Guiada por Imagem/métodos , Pulmão , Tomografia Computadorizada de Feixe Cônico , Planejamento da Radioterapia Assistida por Computador/métodos , Erros de Configuração em Radioterapia/prevenção & controle
6.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-507506

RESUMO

Phylogenetically distant coronaviruses have evolved to use ACE2 as their common receptors, including NL63 and many Severe acute respiratory syndrome (SARS) coronavirus-related viruses. We recently reported two Middle East respiratory syndrome coronavirus (MERS-CoV) closely related bat merbecoviruses, NeoCoV and PDF-2180, use Angiotensin-converting enzyme 2 (ACE2) for entry. However, their host range and cross-species transmissibility remain unknown. Here, we characterized their species-specific receptor preference by testing ACE2 orthologs from 49 bats and 53 non-bat mammals. Both viruses exhibited broad receptor recognition spectra and are unable to use ACE2 orthologs from 24 species, mainly Yinpterochiropteran bats. Comparative analyses of bat ACE2 orthologs underscored four crucial host range determinants, all confirmed by subsequent functional assays in human and bat cells. Among them, residue 305, participating in a critical interaction, plays a crucial role in host tropism determination. NeoCoV-T510F, a mutation that enhances human ACE2 recognition, further expanded the potential host range via tighter interaction with an evolutionary conserved hydrophobic pocket. Our results elucidated the molecular basis for the species-specific ACE2 usage of MERS-related viruses across mammals and shed light on their zoonotic risks.

7.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-477490

RESUMO

Middle East Respiratory Syndrome coronavirus (MERS-CoV) and several bat coronaviruses employ Dipeptidyl peptidase-4 (DPP4) as their functional receptors1-4. However, the receptor for NeoCoV, the closest MERS-CoV relative yet discovered in bats, remains enigmatic5. In this study, we unexpectedly found that NeoCoV and its close relative, PDF-2180-CoV, can efficiently use some types of bat Angiotensin-converting enzyme 2 (ACE2) and, less favorably, human ACE2 for entry. The two viruses use their spikes S1 subunit carboxyl-terminal domains (S1-CTD) for high-affinity and species-specific ACE2 binding. Cryo-electron microscopy analysis revealed a novel coronavirus-ACE2 binding interface and a protein-glycan interaction, distinct from other known ACE2-using viruses. We identified a molecular determinant close to the viral binding interface that restricts human ACE2 from supporting NeoCoV infection, especially around residue Asp338. Conversely, NeoCoV efficiently infects human ACE2 expressing cells after a T510F mutation on the receptor-binding motif (RBM). Notably, the infection could not be cross-neutralized by antibodies targeting SARS-CoV-2 or MERS-CoV. Our study demonstrates the first case of ACE2 usage in MERS-related viruses, shedding light on a potential bio-safety threat of the human emergence of an ACE2 using "MERS-CoV-2" with both high fatality and transmission rate.

8.
Chemosphere ; 291(Pt 2): 132954, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34800505

RESUMO

As a clean and efficient technology for the degradation of organic contaminants, sulfate radical based advanced oxidation processes (SR-AOPs) have attracted more and more attention in the past decades. Cobalt is regarded as the most reactive and efficient non-noble metal catalyst for the activation of persulfate including peroxymonosulfate (PMS) and peroxydisulfate (PDS) to produce sulfate radicals. Due to the limitations of homogeneous catalytic systems, the heterogeneous cobalt-containing catalysts have been emerged and rapidly developed. Various strategies have been schemed to further enhance the activation ability of persulfate by heterogeneous cobalt-containing catalysts. This paper provides an overview on the recent progress in enhancement strategies for the highly efficient activation of persulfate by heterogeneous cobalt-containing catalysts. With a brief introduction on the chemistry and feature of sulfate radical reactions catalyzed by homogeneous Co2+/Co3+ species, the main strategies for enhancing persulfate activation by heterogeneous cobalt-containing catalysts are summarized, such as surface and morphology design, multiple reactive centers design, organic-inorganic hybrids and heterostructure composites. Future perspectives of heterogeneous SR-AOPs systems catalyzed by cobalt-containing catalysts are outlined.


Assuntos
Cobalto , Metais , Catálise , Oxirredução
9.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-954784

RESUMO

Autism spectrum disorder (ASD) is a group of neurodevelopmental behavioral disorders, with the annually increased incidence in recent years.As one of the core symptoms of ASD, sensory abnormality not only affects the skill acquisition of affected children, but also brings great pain to caregivers and families.It is shown that early intervention of sensory abnormality can significantly improve the prognosis of ASD.However, early intervention depends on the early identification and diagnosis of sensory abnormality by clinicians.This study aims to review the clinical features, assessment tools, and intervention methods of sensory abnormalities in ASD children in recent years, thus contribu-ting to the accurate and effective diagnosis, and timely intervention of ASD.

10.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-955938

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide nowadays. Given the very complex pathogenesis, there are yet no effective pharmacological agents for the treatment of NAFLD. Accumulating evidence has shown that cholesterol metabolism dysregulation, resulting in excess cholesterol accumulation in the liver and subsequent hepatic inflammation and injury, is one of the most important causes for the occurrence and development of NAFLD. This suggests the application of cholesterol metabolism- targeting therapeutic strategy in NAFLD. This review firstly summarized the pathogenesis of NAFLD, then focused on the regulation of cholesterol metabolism and underlying mechanisms through which excess hepatic cholesterol contributed to NAFLD, and reviewed the research progress on cholesterol-lowering agents aimed at maintaining the cholesterol homeostasis to treat NAFLD, which would provide insights for novel strategies to treat NAFLD in both preclinical studies and clinical settings.

11.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-473594

RESUMO

SARS-CoV-2 continued to spread globally along with different variants. Here, we systemically analyzed viral infectivity and immune-resistance of SARS-CoV-2 variants to explore the underlying rationale of viral mutagenesis. We found that the Beta variant harbors both high infectivity and strong immune resistance, while the Delta variant is the most infectious with only a mild immune-escape ability. Remarkably, the Omicron variant is even more immune-resistant than the Beta variant, but its infectivity increases only in Vero E6 cells implying a probable preference for the endocytic pathway. A comprehensive analysis revealed that SARS-CoV-2 spike protein evolved into distinct evolutionary paths of either high infectivity plus low immune resistance or low infectivity plus high immune resistance, resulting in a narrow spectrum of the current single-strain vaccine. In light of these findings and the phylogenetic analysis of 2674 SARS-CoV-2 S-protein sequences, we generated a consensus antigen (S6) taking the most frequent mutations as a pan-vaccine against heterogeneous variants. As compared to the ancestry SWT vaccine with significantly declined neutralizations to emerging variants, the S6 vaccine elicits broadly neutralizing antibodies and full protections to a wide range of variants. Our work highlights the importance and feasibility of a universal vaccine strategy to fight against antigen drift of SARS-CoV-2.

12.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-455523

RESUMO

SARS-CoV-2 infection is initiated with Spike glycoprotein binding to the receptor of human angiotensin converting enzyme 2 via its receptor binding domain. Blocking this interaction is considered as an effective approach to inhibit virus infection. Here we report the discovery of a neutralizing nanobody, VHH60, directly produced from a humanized synthetic nanobody library. VHH60 competes with human ACE2 to bind the receptor binding domain of the Spike protein with a KD of 2.56 nM, inhibits infections of both live SARS-CoV-2 and pseudotyped viruses harboring wildtype, escape mutations and prevailing variants at nanomolar level. VHH60 also suppresses SARS-CoV-2 infection and propagation 50-fold better and protects mice from death two times longer than that of control group after live virus inoculation on mice. VHH60 therefore is a powerful synthetic nanobody with a promising profile for disease control against COVID19.

13.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-21258673

RESUMO

Most COVID-19 patients can build effective humoral immunity against SARS-CoV-2 after recovery(1, 2). However, it remains unknown how long the protection can maintain and how efficiently it can protect people from the reinfection of the emerging SARS-CoV-2 variants. Here we evaluated the sera from 248 COVID-19 convalescents around one year post-infection in Wuhan, the earliest epicenter of SARS-CoV-2. We demonstrated that the SARS-CoV-2 immunoglobulin G (IgG) maintains at a high level and potently neutralizes the infection of the original strain (WT) and the B.1.1.7 variant in most patients. However, they showed varying degrees of efficacy reduction against the other variants of concern (P.1, B.1.525, and especially B.1.351) in a patient-specific manner. Mutations in RBD including K417N, E484K, and E484Q/L452R (B.1.617) remarkably impair the neutralizing activity of the convalescents sera. Encouragingly, we found that a small fraction of patients sera showed broad neutralization potency to multiple variants and mutants, suggesting the existence of broadly neutralizing antibodies recognizing the epitopes beyond the mutation sites. Our results suggest that the SARS-CoV-2 vaccination effectiveness relies more on the timely re-administration of the epitope-updated vaccine than the durability of the neutralizing antibodies.

14.
Nanotechnology ; 32(26)2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33361556

RESUMO

Characterizing electrical breakdown limits of materials is a crucial step in device development. However, methods for repeatable measurements are scarce in two-dimensional materials, where breakdown studies have been limited to destructive methods. This restricts our ability to fully account for variability in local electronic properties induced by surface contaminants and the fabrication process. To tackle this, we implement a two-step deep-learning model to predict the breakdown mechanism and breakdown voltage of monolayer MoS2devices with varying channel lengths and resistances using current measured in the low-voltage regime as inputs. A deep neural network (DNN) first classifies between Joule and avalanche breakdown mechanisms using partial current traces from 0 to 20 V. Following this, a convolutional long short-term memory network (CLSTM) predicts breakdown voltages of these classified devices based on partial current traces. We test our model with electrical measurements collected using feedback-control of the applied voltage to prevent device destruction, and show that the DNN classifier achieves an accuracy of 79% while the CLSTM model has a 12% error when requiring only 80% of the current trace as inputs. Our results indicate that information encoded in the current behavior far from the breakdown point can be used for breakdown predictions, which will enable non-destructive and rapid material characterization for 2D material device development.

15.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-879813

RESUMO

OBJECTIVE@#To study the effect of calorie-enriched formula on postoperative catch-up growth in infants with cyanotic congenital heart disease (CHD).@*METHODS@#A total of 100 infants with cyanotic CHD who underwent surgical operation from January to December, 2017, were randomly divided into a high-calorie group (receiving calorie-enriched formula after surgery) and a conventional group (receiving standard formula after surgery), with 50 infants in each group. All infants were followed up for 6 months. The observation indices included body height, body weight, prealbumin, and N-terminal pro-brain natriuretic peptide before surgery, at the time of ventilator weaning and extubation after surgery, and at 1, 3, and 6 months after surgery. Height-for-age Z-score (HAZ), weight-for-age Z-score (WAZ), and weight-for-height Z-score (WHZ) were also assessed. Adverse reactions were recorded for both groups.@*RESULTS@#There were 25 cases (50%) and 21 cases (42%) of malnutrition in the high-calorie group and the conventional group respectively before surgery (@*CONCLUSIONS@#Compared with the standard formula, calorie-enriched formula can better help with postoperative catch-up growth in infants with cyanotic CHD.


Assuntos
Humanos , Lactente , Peso Corporal , Ingestão de Energia , Cardiopatias Congênitas/cirurgia , Desnutrição , Estado Nutricional , Estudos Prospectivos
16.
Acta Pharmaceutica Sinica ; (12): 793-798, 2021.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-876516

RESUMO

Dengue virus (DENV) is the most rapidly transmitted mosquito-borne pathogen, which is the main cause of seasonal outbreaks of dengue fever and dengue hemorrhagic fever in tropical and subtropical regions, and may cause serious life-threatening diseases. There is an urgent need to develop effective vaccines or antiviral therapies. In this paper, we found that a podocarpane-type diterpenoid, (3α,5β,10α)-13-methoxypodocarpa-8,11,13-triene-3,12-diol (MPTD), isolated from the stems and leaves of Aleurites moluccana, showed good effect against DENV. The anti-DENV activity of MPTD against four different DENV serotypes was studied by plaque assay. The cytotoxicity of MPTD in Vero and Huh7 cells was tested by MTT assay. qRT-PCR and Western blot assays were used to investigate the anti-DENV activity of MPTD at RNA and protein levels, respectively. The results showed that MPTD greatly reduced the virus titer in DENV infected Vero cells, and its 50% effective concentration (EC50) for DENV (1–4) were 2.72 ± 0.39, 10.99 ± 5.18, 18.72 ± 0.21, and 0.48 ± 0.28 μmol·L-1, respectively. The results showed that MPTD inhibits DENV RNA level and the expression of E protein. In addition, MPTD may inhibit the early stage of DENV replication and exert antiviral activity. Further studies showed that the inhibitory effect of MPTD against DENV infection is not targeting the viral entry stage. Therefore, MPTD has a significant anti-dengue virus effect, and is an anti-DENV compound with potential application value.

17.
ACS Omega ; 5(47): 30444-30453, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33283092

RESUMO

In this work, well-dispersed fumed SiO2/cis-1,4-polyisoprene rubber (IR) masterbatch was first obtained through an effective wet mixing method, and the properties of the corresponding vulcanizate were studied. Before curing with activator and sulfur, IR solution was blended and co-coagulated with SiO2 suspension modified by bis(3-trimethoxysilypropyl) tetrasulfide in n-hexane. The modification of TESPT imparted evenly distributed SiO2 particles in IR and improved interfacial binding among SiO2 and IR. Hence, the prepared compound presented better processability and the corresponding vulcanizate presented higher physical performance, including higher tensile strength, lower heat buildup, and better fatigue resistance than that prepared in the dry mixing method. Additionally, higher wet skid resistance and lower rolling resistance could be observed in fabricated SiO2/IR vulcanizate. The employed wet mixing method is economical and efficient, which is promising in preparing rubber composites with comprehensive performance.

18.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-335893

RESUMO

The upcoming flu season in the northern hemisphere merging with the current COVID-19 pandemic raises a potentially severe threat to public health. Through experimental co-infection of IAV with either pseudotyped or SARS-CoV-2 live virus, we found that IAV pre-infection significantly promoted the infectivity of SARS-CoV-2 in a broad range of cell types. Remarkably, increased SARS-CoV-2 viral load and more severe lung damage were observed in mice co-infected with IAV in vivo. Moreover, such enhancement of SARS-CoV-2 infectivity was not seen with several other viruses probably due to a unique IAV segment as an inducer to elevate ACE2 expression. This study illustrates that IAV has a special nature to aggravate SARS-CoV-2 infection, and prevention of IAV is of great significance during the COVID-19 pandemic.

19.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-284737

RESUMO

Bats are the suggested natural hosts for severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2, the latter of which caused the coronavirus disease 2019 (COVID-19) pandemic. The interaction of viral Spike proteins with their host receptor angiotensin-converting enzyme 2 (ACE2) is a critical determinant of potential hosts and cross-species transmission. Here we use virus-host receptor binding and infection assays to show that ACE2 orthologs from 24, 21, and 16 of 46 phylogenetically diverse bat species - including those in close and distant contact with humans - do not support entry of SARS-CoV, SARS-CoV-2, and both of these coronaviruses, respectively. Furthermore, we used genetic and functional analyses to identify genetic changes in bat ACE2 receptors associated with viral entry restrictions. Our study demonstrates that many - if not most - bat species are not potential hosts of SARS-CoV and SARS-CoV-2, and provides important insights into pandemic control and wildlife conservation.

20.
Water Sci Technol ; 81(5): 1080-1089, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32541124

RESUMO

Bismuth oxyhalides (BiOXs, X = Cl, Br and I) are emerging photocatalytic materials with unique layered structure, flexible band structure and superior photocatalytic activity. The purpose of this study was to develop a facile alcoholysis route to prepare BiOClxI1-x nanosheet solid solutions at room temperature. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), photoluminescence emission spectroscopy (PL) and Brunauer-Emmett-Teller (BET) surface area analyzer were used to characterize the as-prepared photocatalysts. These results revealed that two-dimension BiOClxI1-x nanosheet solid solutions could be obtained with high percentage of {001} crystal facets exposed. Moreover, the formation of solid solution could regularly change the optical absorption thresholds and band gaps of BiOClxI1-x photocatalysts. The photocatalytic experiments indicated that BiOCl0.75I0.25 exhibited the highest photocatalytic performance for the degradation of Rhodamine B (RhB) under simulated sunlight irradiation and the photocatalytic process followed a pseudo-first-order kinetic equation. A possible mechanism of RhB photodegradation over BiOClxI1-x solid solutions was proposed based on the structural properties of BiOClxI1-x solid solutions and RhB photosensitization.


Assuntos
Luz , Água , Catálise , Rodaminas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...