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1.
Phys Rev Lett ; 132(22): 221802, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38877918

RESUMO

To enhance the scientific discovery power of high-energy collider experiments, we propose and realize the concept of jet-origin identification that categorizes jets into five quark species (b,c,s,u,d), five antiquarks (b[over ¯],c[over ¯],s[over ¯],u[over ¯],d[over ¯]), and the gluon. Using state-of-the-art algorithms and simulated νν[over ¯]H,H→jj events at 240 GeV center-of-mass energy at the electron-positron Higgs factory, the jet-origin identification simultaneously reaches jet flavor tagging efficiencies ranging from 67% to 92% for bottom, charm, and strange quarks and jet charge flip rates of 7%-24% for all quark species. We apply the jet-origin identification to Higgs rare and exotic decay measurements at the nominal luminosity of the Circular Electron Positron Collider and conclude that the upper limits on the branching ratios of H→ss[over ¯],uu[over ¯],dd[over ¯] and H→sb,db,uc,ds can be determined to 2×10^{-4} to 1×10^{-3} at 95% confidence level. The derived upper limit for H→ss[over ¯] decay is approximately 3 times the prediction of the standard model.

2.
Sci Total Environ ; 924: 171665, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38490406

RESUMO

Pyrolysis holds immense potential for clean treatment of pulp and paper mill sludge (PPMS), enabling efficient energy and chemical recovery. However, current understanding of PPMS pyrolysis kinetics and product characteristics remains incomplete. This study conducted detailed modeling of pyrolysis kinetics for two typical PPMSs from a wastepaper pulp and paper mill, namely, deinking sludge (PPMS-DS) and sewage sludge (PPMS-SS), and analyzed comprehensively pyrolysis products. The results show that apparent activation energy of PPMS-DS (169.25-226.82 kJ/mol) and PPMS-SS (189.29-411.21 kJ/mol) pyrolysis undergoes significant change, with numerous parallel reactions present. A distributed activation energy model with dual logistic distributions proves to be suitable for modeling thermal decomposition kinetics of both PPMS-DS and PPMS-SS, with coefficient of determination >0.999 and relative root mean square error <1.99 %. High temperature promotes decomposition of solid organic materials in PPMS, and maximum tar yield for both PPMS-DS (53.90 wt%, daf) and PPMS-SS (56.48 wt%, daf) is achieved at around 500 °C. Higher levels of styrene (24.45 % for PPMS-DS and 14.71 % for PPMS-SS) and ethylbenzene (8.61 % for PPMS-DS and 8.33 % for PPMS-SS) are detected in tar and could be used as chemicals. This work shows great potential to propel development of PPMS pyrolysis technology, enabling green and sustainable production in pulp and paper industry.

3.
Soft Matter ; 20(7): 1438-1446, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38258320

RESUMO

Rapid water absorption is very important for the application of superabsorbent polymers under dry or semi-dry conditions, but there are currently few relevant studies. In this context, a novel porous superabsorbent of chitosan-grafted acrylic copolymer-2-acrylamido-2-methylpropanesulfonic acid/sapindus mukorossi pericarp/calcined oil shale semi-coke (CS-g-P(AA-co-AMPS)/SMP/COSSC) was prepared by a green and convenient foam template method, which was triggered by redox polymerization. The rich pore structure of the porous superabsorbent was conducive to accelerating the water absorption rate. It only took 15 min to reach a swelling capacity of 650 g g-1 in distilled water. Soil experiments show that even with the addition of 0.5 wt% porous superabsorbent, the soil water retention time can be extended to 7 days. Finally, it was applied to the growth of cabbage seeds and it was found that the growth was significantly improved. Based on these excellent properties, we expect to provide a valuable reference for the preparation of fast-absorbing materials through the green water-based foam template method, contributing to sustainable agriculture.

4.
Bioresour Technol ; 388: 129754, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37696336

RESUMO

In this study, a novel adsorbent with a sufficient porous structure was fabricated using a green and highly stable water-based foam template. This template was stabilized with agricultural waste quinoa husk (QH) and applied to remove dye pollutants in wastewater. The porous adsorbent exhibited a high adsorption capacity of 740.95 mg/g for methylene blue and 1022.1 mg/g for methyl violet. The adsorption process was well described by the Langmuir-Freundlich model and the pseudo second-order kinetic model. A sustainable concept for handling the spent adsorbent was also proposed, involving its conversion into biochar and safe return to the soil. An additional benefit was observed, as the biochar effectively adjusted the physicochemical properties of the soil and improved crop growth with the addition of 1 wt%. The potential application of porous adsorbent in wastewater treatment and the reference of sustainable strategy for disposing of other adsorbents are both noteworthy.


Assuntos
Chenopodium quinoa , Poluentes Químicos da Água , Adsorção , Porosidade , Solo , Poluentes Químicos da Água/química , Cinética , Azul de Metileno/química
5.
Sensors (Basel) ; 23(5)2023 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-36904781

RESUMO

The cooperative imaging of the bistatic radar is an important research topic for missile-borne radar detection. The existing missile-borne radar detection system is mainly based on the target plot information separately extracted by each radar for data level fusion, without considering the gain brought by the cooperative processing of the radar target echo signal. In this paper, a random frequency-hopping waveform is designed for the bistatic radar to achieve efficient motion compensation. A coherent processing algorithm for bistatic echo signals is designed to achieve band fusion and improve the signal quality and range resolution of the radar. Simulation and high-frequency electromagnetic calculation data were used to verify the effectiveness of the proposed method.

6.
Biomed Mater ; 18(2)2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36657175

RESUMO

The poor mechanical strength and bioactivity of magnesium phosphate bone cements (MPCs) are the vital defects for bone reconstruction. Clay minerals have been widely used in biomedical field due to the good reinforcing property and cytocompatibility. Here, laponite, sepiolite or halloysite were incorporated to fabricate MPCs composite, and the composition, microstructure, setting time, compressive strength, thermal stability, degradation performance,in vitrobioactivity and cell viability of MPCs composite were investigated. The results suggested that the MPCs composite possessed appropriate setting time, high mechanical strength and good thermal stability. By contrast, MPCs composite containing 3.0 wt.% of sepiolite presented the highest compressive strength (33.45 ± 2.87 MPa) and the best thermal stability. The degradation ratio of MPCs composite was slightly slower than that of MPCs, and varied in simulated body fluid and phosphate buffer solution. Therefore, the obtained MPCs composite with excellent bioactivity and cell viability was expected to meet the clinical requirements for filling bone defect.


Assuntos
Cimentos Ósseos , Fosfatos , Cimentos Ósseos/química , Argila , Teste de Materiais , Fosfatos/química , Silicatos de Magnésio , Força Compressiva , Fosfatos de Cálcio/química
7.
Biosens Bioelectron ; 222: 114981, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36473422

RESUMO

With the increasing concerns of food safety and environmental protection, it is desirable to develop reliable, effective, and portable sensors for detection of organophosphorus pesticides (OPs). Here, a cascade reaction system integrated with threaded 3D microfluidic paper analytical device (3D µPAD) was firstly developed for background-free and visual detection of OPs in agricultural samples. Butyrylcholinesterase (BChE) hydrolyzed acetylcholine into thiocholine (TCh), which reduced MnO2 nanosheets into Mn2+. With addition of OPs, BChE activity was irreversibly inhibited, and the generation of TCh and the reduction of MnO2 nanosheets were prevented. Then the remaining MnO2 nanosheets oxidized o-phenylenediamine into 2,3-diaminophenazine with yellow-emission fluorescence, which quenched the fluorescence intensity of red-emission carbon dots (RCDs) via inner-filter effect. Based on above mechanism, a ratiometric fluorescent system was established for OPs detection. Threaded 3D µPAD consisted of 4 layers, which allowed to load and/or add reagents to trigger the cascade reaction system for OPs detection. The fluorescent images presented distinguishable color variations from red to yellow with dichlorvos concentrations ranging from 2.5 to 120 µg L-1, and the limit of detection was 1.0 µg L-1. In the practical samples testing, threaded 3D µPAD can eliminate background influence on fluorescent signal for OPs detection. Threaded 3D µPAD integrated with ratiometric sensing platform has merits of accuracy response, facile operation, and background-free detection, which supplies a new alternative approach for on-site pesticide detection.


Assuntos
Técnicas Biossensoriais , Praguicidas , Compostos Organofosforados , Butirilcolinesterase , Microfluídica , Compostos de Manganês , Óxidos , Técnicas Biossensoriais/métodos , Corantes Fluorescentes
8.
J Environ Sci (China) ; 127: 855-865, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36522113

RESUMO

The water-based foam stabilized by the natural surfactant applied in the fabrication of porous materials has attracted extensive attention, as the advantages of cleanness, convenience and low cost. Particularly, the development of a green preparation method has became the main research focus and frontier. In this work, a green liquid foam with high stability was prepared by synergistic stabilization of natural plant astragalus membranaceus (AMS) and attapulgite (APT), and then a novel porous material with sufficient hierarchical pore structure was templated from the foam via a simple free radical polymerization of acrylamide (AM). The characterization results revealed that the amphiphilic molecules from AMS adsorbed onto the water-air interface and formed a protective shell to prevent the bubble breakup, and APT gathered in the plateau border and formed a three-dimensional network structure, which greatly slowed down the drainage rate. The porous material polyacrylamide/astragalus membranaceus/attapulgite (PAM/AMS/APT) showed the excellent adsorption performance for cationic dyes of Methyl Violet (MV) and Methylene Blue (MB) in water, and the maximum adsorption capacity could reach to 709.13 and 703.30 mg/g, respectively. Furthermore, the polymer material enabled to regenerate and cycle via a convenient calcination process, and the adsorption capacity was still higher than 200 mg/g after five cycles. In short, this research provided a new idea for the green preparation of porous materials and the treatment of water pollution.


Assuntos
Astragalus propinquus , Corantes , Corantes/química , Porosidade , Adsorção , Cátions , Água
9.
Polymers (Basel) ; 14(9)2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35566887

RESUMO

In order to achieve the low cost and multifunction of superabsorbent composites, poly(acrylic acid-co-acrylamide)/fulvic acid/oil shale semicoke (PAMFS) were prepared by free radical copolymerization of fulvic acid (FA), oil shale semicoke (OSSC), acrylic acid (AA) and acrylamide (AM). The characterization results revealed that FA and OSSC were involved in the construction of a three-dimensional (3D) polymeric network via hydrogen bonding and covalent bonding. The water absorbency of PAMFS in distilled water and 0.9 wt% NaCl solution were 724 and 98 g/g, respectively. The FA slow release of PAMFS in distilled water and soil was achieved due to the interaction between FA and the functional groups of polymer matrix by hydrogen bonds and covalent bonds. Furthermore, the potted experiment indicated that the addition of PAMFS to soil can significantly promote plant growth compared with the pure soil, regardless of water stress. Therefore, this superabsorbent composite showed an excellent water absorption and salt resistance performance, as well as nice slow release performance. It has a broad application prospect.

10.
Am J Transl Res ; 14(2): 1034-1042, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35273705

RESUMO

OBJECTIVE: To determine the application effect of sevoflurane combined with remifentanil intravenous inhalation anesthesia in patients undergoing laparoscopic radical resection of cervical cancer (LRHCC). METHODS: The clinical data of 127 patients with cervical cancer (CC) who received LRHCC in Henan Provincial People's Hospital during January 2017 and June 2021 were retrospectively analyzed. Among them, 60 patients anesthetized by propofol combined with remifentanil were assigned to the control group (Con group), while the rest 67 anesthetized by sevoflurane combined with remifentanil to the research group (Res group). The following items of the two groups were compared: the changes of heart rate and blood pressure before anesthesia (T0), at 30 min after anesthesia (T1) and 10 min after surgery (T2), anesthetic effect, stress substance contents, anesthesia recovery, changes in brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), Mini-Mental State Examination (MMSE) scores, and adverse reactions. RESULTS: The heart rate and blood pressure at T1 and T2 were notably different between the two groups (P<0.05). In contrast to the Con group, the Res group showed a greatly better recovery effect of anesthesia and presented notably lower levels of adrenaline and GLU (all P<0.05). 10 min after surgery, the Con group showed lower levels of BDNF and NGF than the Con group. After surgery, the MMSE scores in the Res group were higher than that of the Con group, and the two groups had no significant difference in the incidence of adverse reactions (P>0.05). CONCLUSION: In contrast to propofol combined with remifentanil anesthesia, intravenous inhalational anesthesia with sevoflurane combined with remifentanil can exert a stronger anesthetic effect in patients receiving LRHCC, with a high safety.

11.
Chemosphere ; 290: 132543, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34653486

RESUMO

This study developed a sustainable way to transform metallic residues in wastewater and spent adsorbents that adsorbed organic pollutants into novel high-efficiency adsorbents to treat water pollution again. The metal ions recovered from oxalic acid leaching palygorskite-rich clay wastewater was used to construct the hydrotalcite-like composites, after adsorbing organic pollutants, which was calcined and carbonized to convert into the mixed metal oxide/carbon composites (MMO/Cs). The fabricated MMO/Cs showed outstanding adsorption performance for the anionic azo dye Congo Red (CR). Especially, the MMO/C2 with the M2+/M3+ molar ratio of 2, which adjusted by supplementing Mg2+, had ultra-high adsorption capacity and ultra-clean removal efficiency for CR. The adsorption capacity was as high as 3303 mg/g, and only 0.5 g/L MMO/C2 dosing treatment for 6 h could completely decolor and remove the 2000 mg/L CR aqueous solution. Moreover, MMO/Cs exhibited the ability to simultaneous remove CR and Methylene blue (MB) mixed dye contaminants, and demonstrated the excellent recyclability. This work provides a promising method for the high-value conversion of waste resources and the synthesis of high-efficiency adsorbents.


Assuntos
Vermelho Congo , Poluentes Químicos da Água , Adsorção , Carbono , Argila , Íons , Compostos de Magnésio , Ácido Oxálico , Óxidos , Compostos de Silício , Águas Residuárias
12.
Biosens Bioelectron ; 196: 113691, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34637993

RESUMO

On-site multiplex enzyme detection is crucial for diagnosis, therapeutics and prognostic. To date, it is still a daunting challenge to develop portable, low-cost, and efficient multi-enzyme detection methods. Herein, a novel sample-in-result-out platform integrating ratiometric fluorescent assays with 3D origami microfluidic paper-based device (µPAD) was developed for simultaneous visual point-of-care testing (POCT) of alkaline phosphatase (ALP) and butyrylcholinesterase (BChE). Cascade catalytic reaction with the same two fluorescent signal indicators was rationally designed to ratiometric fluorescent detection of ALP and BChE: substrate of ALP (pyrophosphate) and product of BChE (thiocholine) can strongly complex with Cu2+, Cu2+ oxidizes o-phenylenediamine to fluorescent 2,3-diaminophenazine (oxOPD) (emission, 565 nm), oxOPD quenches the fluorescence of carbon dots (CDs, emission at 445 nm) via inner filter effect, thus oxOPD/CDs values are relevant to ALP and BChE activities. Then 3D origami µPAD composing of four layers and two parallel channels was fabricated and simply prepared by one-step plotting with black oil-based marker and specific metal molds. After simple folding and unfolding neighboring layers to sequentially initiate reactions of pre-loaded reagents, fluorescent images on the detection zone can be captured by smartphone and analyzed by red-green-blue software for quantitative analysis. Under optimal conditions, the proposed platform was successfully performed to detect ALP and BChE with activity difference at 3 orders of magnitude in human serum samples without any pretreatment procedures. Excellent selectivity, good precision, favorable linear range, and high accuracy were exhibited. Importantly, the platform opens a promising horizon for high-throughput POCT of multiplex biomarkers.


Assuntos
Fosfatase Alcalina , Técnicas Biossensoriais , Butirilcolinesterase , Corantes Fluorescentes , Humanos , Dispositivos Lab-On-A-Chip , Limite de Detecção , Sistemas Automatizados de Assistência Junto ao Leito
13.
J Environ Sci (China) ; 112: 320-330, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34955215

RESUMO

Spherical porous materials prepared from the emulsion template used in the water treatment have displayed a vast prospect, as the high surface area, abundant porous structure, convenient operation and excellent adsorption performance. But the tedious fabrication process, high consumption of organic solvent and surfactant limited the application widely. Herein, a facile and eco-friendly spherical porous adsorbent (SPA) is fabricated from the green surfactant-free (corn oil)-in-water Pickering medium internal phase emulsions (Pickering MIPEs) via the convenient ion crosslinking procedure. The Pickering MIPEs synergistically stabilized with the semi-coke (SC), which is the natural particle produced from the shale oil distillation, and sodium alginate (SA) has excellent storage and anti-coalescence stability. The as-prepared porous adsorbent possessed the abundant pore structure, which provided favorable conditions for effective mass transfer in adsorption, and could be tuned by varying the SA dosage. The saturation adsorption capacities of Pb(II) and Cd(II) can be achieved with 460.54 and 278.77 mg/g within 45 min at 25°C, respectively. Overall, this study supplied a viable and eco-friendly route for fabricating the spherical porous adsorbent with a tunable porous structure for heavy metal ion wastewater.


Assuntos
Cádmio , Purificação da Água , Emulsões , Chumbo , Porosidade
14.
Int J Biol Macromol ; 193(Pt B): 1676-1684, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34743028

RESUMO

The radioactive Rb+, Cs+ and Sr2+ have serious threat for the aquatic life and human health, its removal has been granted increasing concern. Hence the adsorbent with excellent adsorption performance and favourable reusability is strongly demanded. This work prepared a novel porous polymer of chitosan-g-polyacrylamide (CTS-g-PAM) by grafting the acrylamide (AM) onto the chitosan (CTS) with sufficient pore structure via an eco-friendly surfactant-free (corn oil)-in-water Pickering medium internal phase emulsion (O/W Pickering MIPE), solely stabilized by CTS. Interestingly, its pore structure could be tuned by varying the emulsion character via changing the molecular weight and concentration of CTS, as well as the pH values. Due to the abundant -COO- and -NH2 functional groups in the porous material of CTS-g-PAM, the high adsorption capacities of 195.43, 237.44 and 185.63 mg/g for Rb+, Cs+ and Sr2+ could be reached within 40, 30 and 20 min, respectively. Moreover, the CTS-g-PAM had excellent regeneration ability and reusability. Herein, we provided a feasible and low-cost pathway for preparation of the porous adsorbent with tunable porous structure for adsorption and separation application.


Assuntos
Césio/química , Quitosana/química , Rubídio/química , Estrôncio/química , Adsorção , Emulsões , Porosidade
15.
Anal Chim Acta ; 1178: 338829, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34482874

RESUMO

Rapid, convenient, sensitive and simultaneous detection of distinct enzymes is urgently needed for diagnosis, therapeutics and prognostic of related diseases. Here, a new strategy for simultaneous monitoring γ-glutamyl transpeptidase (GGT) and alkaline phosphatase (ALP) activity has been fabricated based on dual-emission carbon dots (CDs). CDs were prepared by solvothermal treatment of Actinidia chinensis, which presents two fluorescent emissions at 471 nm (blue channel) and 671 nm (red channel). GGT and ALP activity can be detected based on inner filter effect (IFE) and static quenching effect (SQE) of blue and red channels of CDs, respectively. Linear ranges were 2.5-90 U L-1 and 5-200 U L-1, and limit of detection (LOD) were 0.71 U L-1 and 1.2 U L-1 for GGT and ALP, respectively. Developed CDs can monitor GGT and ALP activity in human serum samples with satisfied recoveries (99.3%-108.6% for GGT, 98.4%-105.4% for ALP). Furthermore, the combination of CDs to sense GGT and ALP activity with OR logic gate can predict human health status. The design and application of dual-emission CDs can also be extended as promising tools to detect multianalytes using different channel signals.


Assuntos
Fosfatase Alcalina , Pontos Quânticos , Carbono , Corantes Fluorescentes , Humanos , Limite de Detecção , gama-Glutamiltransferase
16.
Environ Sci Pollut Res Int ; 28(48): 69042-69058, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34283353

RESUMO

The rapid modernization of the transportation sector has greatly escalated many problems, especially the high energy consumption and vehicle exhaust pollution. How to reduce pollution in the transportation sector has attracted widespread attention in recent years. Based on a balanced panel dataset of 30 Chinese provinces spanning the period of 2005-2017, this study attempts to investigate the influence of technological innovation on the energy-environmental efficiency of the transportation sector (EETS) using the spatial econometric approach. The empirical results suggest that first, transportation-related technological innovation and EETS exhibited obvious hot spots and cold spots at the provincial level in China. Second, technological innovation could facilitate the energy-environmental efficiency of transportation sector in China. Third, one province developing transportation-related technological innovations might promote EETS in its neighboring provinces. Fourth, the transportation-related technological innovation in eastern China could boost EETS, while the transportation-related technological innovation in central and western China had a rebound effect on EETS. One possible innovation is that this study extends the relationship between technological innovation and energy-environmental efficiency to the transportation sector.


Assuntos
Desenvolvimento Econômico , Invenções , China , Eficiência , Poluição Ambiental
17.
Int J Biol Macromol ; 179: 230-238, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33675828

RESUMO

An eco-friendly superabsorbent composites of xanthan gum-g-polyacrylic acid/semi-coke (XG-g-PAA/SC) were fabricated via grafting of polyacrylic acid onto the XG in the presence of SC. The obtained products were characterized in combination with Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The result indicated that the SC interacted with the polymeric network by hydrogen bond or electrostatic interaction. The swelling ratio of the best sample XG-g-PAA/SC (15 wt%) in distilled water and 0.9 wt% NaCl solution was 410.8 and 61.5 g/g by optimizing the polymerization conditions. In addition, compared with the blank sample (only containing soil), it can be found that adding a certain amount of XG-g-PAA/SC can significantly improve the soil water retention efficiency, which can be further proved by the results of plant pot experiment. Based on the above excellent swelling capacity, water holding capacity and plant growth promoting performance, it can be inferred that the XG-g-PAA/SC is expected to become a water retaining agent or soil regulator for plant growth.


Assuntos
Coque , Polissacarídeos Bacterianos/química , Água/química , Adsorção
18.
J Environ Sci (China) ; 102: 352-362, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33637260

RESUMO

The aqueous foam template without any solvent and only using the particles stabilizer has attracted much attention for preparation of the porous adsorbents. Herein, a novel porous adsorbent was fabricated via thermal-initiated polymerization of Pickering aqueous foams, which was stabilized by the natural sepiolite (Sep) and pine pollen, and utilized for the removal of antibiotic from aqueous solution. The stabilizing mechanism of Pickering aqueous foam of that the Sep was modified with the leaching substance from pine pollen and arranged orderly around the bubble to form a dense "shell" structure was revealed. The adsorbents possessed the hierarchical porous structure and excellent adsorption performance for antibiotic of chlorotetracycline hydrochloride (CTC) and tetracycline hydrochloride (TC). The equilibrium adsorption capacities of CTC and TC were achieved with 465.59 and 330.59 mg/g within 60 min at 25°C, respectively. The adsorption process obeyed Langmuir model and pseudo-second-order adsorption kinetic model. This work provided eco-friendly approach for fabricate porous adsorbents for wastewater treatment.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Antibacterianos , Cinética , Porosidade
19.
Medicine (Baltimore) ; 99(51): e23547, 2020 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-33371079

RESUMO

ABSTRACT: This study aims to investigate the clinical characteristics and viral shedding kinetics of asymptomatic patients with coronavirus disease 2019 (COVID-19).The data of 38 asymptomatic patients positive for SARS-CoV-2 nucleic acid were collected from February to March 2020 in Tuanfeng County, Huanggang, Hubei, China. The epidemiology, laboratory examination, chest imaging, viral nucleic acid test results, clinical characteristics, and viral shedding time were summarized in this retrospective study.The study included 20 family members of patients with COVID-19, 10 medical personnel participating in COVID-19 treatment or working in a fever clinic, 6 personnel from quarantine places, 1 individual with a close contact history with confirmed patients, and 1 local epidemic prevention personnel. All were positive for SARS-CoV-2 nucleic acid. The white blood cell (WBC) count, the absolute value of lymphocytes, C-reactive protein (CRP), and D-dimer were normal. Pneumonia manifestations were not found in the chest computed tomography (CT) scan of 36 patients; the remaining 2 cases included a 1-year-old child and a pregnant woman, and they did not undergo chest CT. The viral shedding time was 6 days.All asymptomatic patients with COVID-19 had a history of close contact or exposure. Laboratory tests were normal. Chest imaging did not show any pneumonia manifestation. The viral shedding time was <10 days, which is shorter than that of patients with COVID-19. A timely discovery of such asymptomatic infections is crucial for blocking the spread of the virus and strengthening the prevention and control measures.


Assuntos
Infecções Assintomáticas/epidemiologia , COVID-19/virologia , SARS-CoV-2 , Eliminação de Partículas Virais , Adolescente , Adulto , Infecções Assintomáticas/terapia , COVID-19/sangue , COVID-19/diagnóstico por imagem , COVID-19/epidemiologia , Criança , China/epidemiologia , Feminino , Humanos , Indóis/uso terapêutico , Lactente , Masculino , Medicina Tradicional Chinesa , Pessoa de Meia-Idade , Radiografia Torácica , Estudos Retrospectivos , Adulto Jovem
20.
Polymers (Basel) ; 12(10)2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-33066361

RESUMO

A series of novel superabsorbent composites of poly(acrylic acid)/semicoke were prepared by polymerization of acrylic acid using ammonium persulphate as initiator, N,N'-methylenebisacrylamide as crosslinker and semicoke which was the by-product of coal carbonizing as the inorganic components. FTIR and SEM analysis indicated that the superabsorbent composites had been successfully polymerized and the semicoke participated in construction of the 3D polymeric network. Meanwhile, the effects of initiator, crosslinker, semicoke, and neutralization degree, as well as the pH value, were investigated, and the results showed that superabsorbent composites containing 10% of semicoke possessed the maximum water absorbency of 584 g/g in distilled water and 75 g/g in 0.9% NaCl solution. The superabsorbent composites kept the high water absorbency within a wide pH range of 4-11, and still exhibited better re-swelling capability even after seven times. The superabsorbent composite with its excellent performance is a potential water-retaining agent used in agriculture.

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