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1.
Proc Natl Acad Sci U S A ; 121(17): e2314353121, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38635634

RESUMO

Auxin regulates plant growth and development through downstream signaling pathways, including the best-known SCFTIR1/AFB-Aux/IAA-ARF pathway and several other less characterized "noncanonical" pathways. Recently, one SCFTIR1/AFB-independent noncanonical pathway, mediated by Transmembrane Kinase 1 (TMK1), was discovered through the analyses of its functions in Arabidopsis apical hook development. Asymmetric accumulation of auxin on the concave side of the apical hook triggers DAR1-catalyzed release of the C-terminal of TMK1, which migrates into the nucleus, where it phosphorylates and stabilizes IAA32/34 to inhibit cell elongation, which is essential for full apical hook formation. However, the molecular factors mediating IAA32/34 degradation have not been identified. Here, we show that proteins in the CYTOKININ INDUCED ROOT WAVING 1 (CKRW1)/WAVY GROWTH 3 (WAV3) subfamily act as E3 ubiquitin ligases to target IAA32/34 for ubiquitination and degradation, which is inhibited by TMK1c-mediated phosphorylation. This antagonistic interaction between TMK1c and CKRW1/WAV3 subfamily E3 ubiquitin ligases regulates IAA32/34 levels to control differential cell elongation along opposite sides of the apical hook.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas F-Box , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Ácidos Indolacéticos/metabolismo , Transdução de Sinais , Ubiquitinas/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas F-Box/genética , Proteínas F-Box/metabolismo
2.
Chemistry ; 29(34): e202301048, 2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37022345

RESUMO

Tetrathiafulvalene (TTF) and Ni-bis(dithiolene) are typical conductive units widely studied in electronics, optics, and photochemistry. However, their applications in near-infrared (NIR) photothermal conversion are often limited by insufficient NIR absorption and low chemical/thermal stability. Herein, we integrate TTF and Ni-bis(dithiolene) into a covalent organic framework (COF) with stable and efficient NIR and solar photothermal conversion performance. Two isostructural COFs, namely Ni-TTF and TTF-TTF, are successfully isolated which are composed of TTF and Ni-bis(dithiolene) units as donor-acceptor (D-A) pairs or TTF units only. Both COFs show high BET surface areas and good chemical/thermal stability. Notably, compared with TTF-TTF, the periodic D-A arrangement in Ni-TTF significantly lowers the bandgap, leading to unprecedented NIR and solar photothermal conversion performance.

3.
Inorg Chem ; 61(7): 3078-3085, 2022 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-35142506

RESUMO

Metal-organic frameworks (MOFs) provide broad prospects for the development of new photothermal conversion materials, while their design and synthesis remain challenging. A new Zn-MOF (1) containing both tetrathiafulvalene (TTF) as an electron donor and naphthalene diimide (NDI) as an electron acceptor was constructed by using a space limiting effect. The material exhibited wide absorption peaks in the near-infrared region, indicating that there was strong charge transfer interaction between the TTF and NDI units and providing the possibility of photothermal conversion. 1 shows efficient near-infrared photothermal conversion performance. Under 808 nm laser (0.4 W cm-2) illumination, the temperature of 1 increased rapidly from room temperature to 250 °C, with good thermal stability and cycle durability. This work provides an efficient strategy for promising materials in photothermal therapy.

4.
Zhongguo Zhong Yao Za Zhi ; 47(22): 5965-5977, 2022 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-36471922

RESUMO

The blood-brain barrier(BBB), a protective barrier between brain tissues and brain capillaries, can prevent drugs from entering the brain tissues to exert the effect, which greatly increases the difficulty in treating brain diseases. The drug delivery system across the BBB can allow efficient drug delivery across the BBB by virtue of carriers and formulations, thereby enhancing the therapeutic effect of drugs on brain tissue diseases. Liposomes and micelles have been extensively studied with advances in the targeted therapy across the BBB for the brain due to their unique structures and drug delivery advantages. This study summarized the research status of liposome and micelle drug delivery systems across the BBB based on the literature in recent years and analyzed their application advantages and mechanism in terms of trans-BBB capability, targeting, and safety. Moreover, the problems and possible countermeasures in the research on trans-BBB liposomes and micelles were discussed according to the current clinical translation, which may provide refe-rences and ideas for the development of trans-BBB targeted nano-drugs.


Assuntos
Barreira Hematoencefálica , Encefalopatias , Humanos , Lipossomos , Micelas , Sistemas de Liberação de Medicamentos , Transporte Biológico , Encéfalo
5.
Chemistry ; 27(43): 11050-11055, 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-33988893

RESUMO

Metal-organic frameworks (MOFs), as a class of new inorganic-organic hybrid crystal materials, could have important applications in near-infrared (NIR) photothermal conversion. Herein, a new charge-transfer MOF (Co-MOF) with mixed ligands of H4 TTFTB and bpmNDI incorporating redox-active tetrathiafulvalene/naphthalene diimide (TTF/NDI) units into one system is reported. Due to the presence of TTF/NDI oxidative and reductive couples, stable radicals can be observed in the MOF. In addition, charge transfer from the electron donor (TTF) to the acceptor (NDI) results in a broad absorption in the NIR region. The Co-MOF exhibited an efficient photothermal effect induced by irradiation with a NIR laser. Under the 808 nm laser (0.7 W cm-2 ) illumination, the temperature of the Co-MOF increased from room temperature to 201 °C in only 10 s. Furthermore, a series of polydimethylsiloxane (PDMS) films doped with trace amounts of Co-MOF showed efficient NIR photothermal conversion. When a Co-MOF@PDMS (0.6 wt %) film is irradiated by 808 nm laser with power of 0.5 W cm-2 , it's temperature can reach a plateau at 62 °C from 20 °C within 100 s. Our experimental results from the Co-MOF@PDMS film demonstrate that the effectiveness and feasibility of the material is promising for photothermal applications.

6.
Inorg Chem ; 60(11): 8331-8338, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34038101

RESUMO

Controlled hydration leads to four derivatives of a metal-organic framework consisting of cadmium ions, N1,N1,N4,N4-tetrakis(4-(pyridin-4-yl)phenyl)benzene-1,4-diamine, and coordinated and free nitrates. The balance of water coordination and the multitude of bonding of the weakly coordinated nitrate lead to a progressive change in the coordination number of the Cd2+ ions from eight to seven to six without great perturbation to the 4-fold interpenetration three-dimensional framework.

7.
J Craniofac Surg ; 32(2): e167-e171, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33705062

RESUMO

ABSTRACT: The calcifying epithelial odontogenic tumor (CEOT) is a rare benign odontogenic tumor, which usually presents with distension of affected tissues. Radiologically, the lesions are often associated with an unerupted tooth and may have spot calcification shadows. The authors report a case of a CEOT in a 48-year-old male involving the right mandibular jaw bone and mentum soft tissues. The authors performed hemimandibulectomy and enucleation followed by reconstruction of the mandible using a vascularized free fibular flap through a digital surgical technique in order to restore the patient's facial symmetry and prepare the area for functional restorations. The case illustrates who the free fibular flap graft can be used for satisfactory mandibular reconstruction and restoration of the morphology and functions.


Assuntos
Retalhos de Tecido Biológico , Neoplasias Mandibulares , Reconstrução Mandibular , Tumores Odontogênicos , Neoplasias Cutâneas , Fíbula/cirurgia , Humanos , Masculino , Neoplasias Mandibulares/diagnóstico por imagem , Neoplasias Mandibulares/cirurgia , Pessoa de Meia-Idade , Tumores Odontogênicos/diagnóstico por imagem , Tumores Odontogênicos/cirurgia
8.
Angew Chem Int Ed Engl ; 59(50): 22397-22402, 2020 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-32893447

RESUMO

Driven by the persisting poor understanding of the sluggish kinetics of the hydrogen evolution reaction (HER) on Pt in alkaline media, a direct correlation of the interfacial water structure and activity is still yet to be established. Herein, using Pt and Pt-Ni nanoparticles we first demonstrate a strong dependence of the proton donor structure on the HER activity and pH. The structure of the first layer changes from the proton acceptors to the donors with increasing pH. In the base, the reactivity of the interfacial water varied its structure, and the activation energies of water dissociation increased in the sequence: the dangling O-H bonds < the trihedrally coordinated water < the tetrahedrally coordinated water. Moreover, optimizing the adsorption of H and OH intermediates can re-orientate the interfacial water molecules with their H atoms pointing towards the electrode surface, thereby enhancing the kinetics of HER. Our results clarified the dynamic role of the water structure at the electrode-electrolyte interface during HER and the design of highly efficient HER catalysts.

9.
Zhongguo Zhong Yao Za Zhi ; 44(23): 5102-5108, 2019 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-32237344

RESUMO

Metabolic syndrome,a kind of clinical syndrome marked by the presence of symptoms such as hyperglycemia,dyslipidemia and hypertension,has an increasing incidence and comes to be present in younger people. More importantly,prolonged maintenance of this condition can significantly increase the incidence of chronic diseases such as diabetes,cardiovascular disease and cancer.However,the formation mechanism of metabolic syndrome is very complex and has not been fully studied and revealed. Dendrobium officinale is a traditional medicine and food substance with multiple physiological functions. In recent years,D. officinale has attracted much attention from the scholars both at home and abroad due to its functions such as improving blood lipid,lowering blood pressure and regulating blood sugar. However,there is no systematic review on the current studies about D. officinale in intervening metabolic syndrome and its underlying molecular mechanism. In this paper,the biological activity of the main active components,and the research or application status of D. officinale extract in the recent years were reviewed. Then,we analyzed the digestion,absorption and the safety and toxicity of D. officinale and its active components in the body. Finally,we summarized the effects of D. officinale and its active components on metabolic syndrome in animals and human bodies,and discussed its possible molecular mechanisms at the cellular level. This paper provides solid theoretical guidance and reliable molecular basis for further research and advanced development of D. officinale and its active components,especially for its oncoming clinical application.


Assuntos
Dendrobium/química , Síndrome Metabólica/tratamento farmacológico , Preparações de Plantas/farmacologia , Animais , Pressão Sanguínea , Humanos
10.
BMC Public Health ; 14: 1004, 2014 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-25257142

RESUMO

BACKGROUND: High breast cancer mortality has been attributed to lack of public awareness, which leads to late diagnoses. As little is known about the level of knowledge and awareness of breast cancer in China, this study was designed to explore it among women in Eastern China. METHODS: We conducted a cross-sectional survey covering 122,058 females around Shandong, Hebei, Jiangsu and Tianjin, in Eastern China, using in-person interviews based on a self-designed structured questionnaire. Student's t-test, Pearson's χ2 test, reliability analysis, exploratory factor analysis, univariate and multivariate logistic regression analyses were performed in the statistical analysis. RESULTS: The results showed poor awareness of breast cancer among women aged 25-70 years in Eastern China. Only 18.6% of women were highly aware in the study, whereas 81.4% were poorly aware. Among all participants, family history of breast cancer was the best accepted risk factor for breast cancer (awareness rate 31.5%), followed by menarche at age before 12 (11.2%), no parity or late childbirth (13.9%), menopause at a late age (13.7%), high-fat diets (19.1%), long time drinking (19.5%) and long-term use of estrogen drugs (20.7%). Multivariate logistic regression analysis (α = 0.05) identified nine variables that predicted awareness of breast cancer: age (OR = 0.975, 95% CI: 0.960-0.990), location (OR = 1.675, 95% CI: 1.602-1.752), occupation (OR = 4.774, 95% CI: 4.316-5.281), family history of breast cancer (OR = 1.234, 95% CI: 1.073-1.420), household annual income (OR = 0.418, 95% CI: 0.400-0.436), behavioral prevention score (OR = 4.137, 95% CI: 3.991-4.290), no smoking (OR = 2.113, 95% CI: 1.488-2.999), no drinking (OR = 1.427, 95% CI: 1.018-2.000), overall life satisfaction (OR = 0.707, 95% CI: 0.683-0.731). CONCLUSIONS: Our study indicates insufficient awareness of breast cancer among women in Eastern China, and an urgent need for health education programs on this subject.


Assuntos
Neoplasias da Mama/epidemiologia , Neoplasias da Mama/psicologia , Comportamentos Relacionados com a Saúde , Conhecimentos, Atitudes e Prática em Saúde , Adulto , Idoso , Neoplasias da Mama/diagnóstico , China/epidemiologia , Estudos Transversais , Feminino , Humanos , Entrevistas como Assunto , Pessoa de Meia-Idade , Gravidez , Fatores de Risco , Inquéritos e Questionários
11.
Inorg Chem ; 52(11): 6407-16, 2013 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-23692376

RESUMO

A series of seven-coordinate mononuclear lanthanide(III) complexes of the general formula [(TPP)Ln(L(OEt))]·0.25H2O and [(Pc)Ln(L(OEt))] (Ln(3+) = Dy(3+), Tb(3+), Ho(3+), and Gd(3+); TPP = 5,10,15,20-tetraphenylporphyrinate; Pc = phthalocyaninate; L(OEt)(-) = [(η(5)-C5H5)Co(P(=O)(OEt)2)3](-)) are synthesized on the basis of the tripodal ligand L(OEt)(-) and either porphyrin or phthalocyanine ligands. All of the complexes are characterized by X-ray crystallography and by static and dynamic magnetic measurements. The Dy and Tb complexes show the field-induced slow relaxation of magnetization, and they are interesting seven-coordinate single-lanthanide-based SMMs. The magnetic relaxation properties of these double-decker sandwich complexes are influenced by the local molecular symmetry and are sensitive to subtle distortions of the coordination geometry of the paramagnetic lanthanide ions, such as metal-to-plane distances, plane center distances, and bending angles.


Assuntos
Indóis/química , Elementos da Série dos Lantanídeos/química , Compostos Organometálicos/química , Compostos Organometálicos/síntese química , Porfirinas/química , Isoindóis , Ligantes , Campos Magnéticos , Modelos Moleculares , Estrutura Molecular
12.
World J Surg Oncol ; 11: 71, 2013 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-23497298

RESUMO

BACKGROUND: This study was designed to explore the relationship between obesity, diabetes mellitus (DM), and female breast cancer in Eastern China. METHODS: A 1:3 matched case-control study was carried out, comprising 123 women with breast cancer and 369 controls. All of the 492 subjects were selected from a previous epidemiological survey of 122,058 women in Eastern China. RESULTS: There were significant differences between the case and control groups in waist circumference and body mass index (BMI), but not in waist to hip ratio or hip circumference. There was a significant difference between the two groups in BMI for post-menopausal women, and a significant difference in waist circumference for pre-menopausal women. After adjustment for other factors, BMI was still significantly associated with breast cancer (odds ratio (OR) = 1.58, 95% confidence interval (CI) 1.14 to 2.19). DM was significantly associated with breast cancer (OR = 3.35, 95% CI 1.02 to 11.01) in the univariate analysis but not in the multivariate analysis (P = 0.059). CONCLUSIONS: Obesity might be a risk factor for female breast cancer. We found different strengths of association for women with different menopausal status when we examined the relationship between obesity and breast cancer. The association between DM and female breast cancer should be further confirmed with larger sample sizes.


Assuntos
Neoplasias da Mama/etiologia , Diabetes Mellitus Tipo 2/complicações , Obesidade/complicações , Adulto , Idoso , Índice de Massa Corporal , Estudos de Casos e Controles , China , Feminino , Humanos , Modelos Logísticos , Pessoa de Meia-Idade , Análise Multivariada , Obesidade/diagnóstico , Razão de Chances , Pós-Menopausa , Pré-Menopausa , Modelos de Riscos Proporcionais , Fatores de Risco , Circunferência da Cintura , Relação Cintura-Quadril
13.
J Am Chem Soc ; 134(18): 7851-60, 2012 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-22519825

RESUMO

A non isolated pentagon rule metallic sulfide clusterfullerene, Sc(2)S@C(s)(10528)-C(72), has been isolated from a raw mixture of Sc(2)S@C(2n) (n = 35-50) obtained by arc-discharging graphite rods packed with Sc(2)O(3) and graphite powder under an atmosphere of SO(2) and helium. Multistage HPLC methods were utilized to isolate and purify the Sc(2)S@C(72). The purified Sc(2)S@C(s)(10528)-C(72) was characterized by mass spectrometry, UV-vis-NIR absorption spectroscopy, cyclic voltammetry, and single-crystal X-ray diffraction. The crystallographic analysis unambiguously elucidated that the C(72) fullerene cage violates the isolated pentagon rule, and the cage symmetry was assigned to C(s)(10528)-C(72). The electrochemical behavior of Sc(2)S@C(s)(10528)-C(72) shows a major difference from those of Sc(2)S@C(s)(6)-C(82) and Sc(2)S@C(3v)(8)-C(82) as well as the other metallic clusterfullerenes. Computational studies show that the Sc(2)S cluster transfers four electrons to the C(72) cage and C(s)(10528)-C(72) is the most stable cage isomer for both empty C(72)(4-) and Sc(2)S@C(72), among the many possibilities. The structural differences between the reported fullerenes with C(72) cages are discussed, and it is concluded that both the transfer of four electrons to the cage and the geometrical requirements of the encaged Sc(2)S cluster play important roles in the stabilization of the C(s)(10528)-C(72) cage.

14.
Adv Mater ; 34(23): e2201716, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35435291

RESUMO

Aqueous Zn-iodine (Zn-I2 ) batteries have been regarded as a promising energy-storage system owing to their high energy/power density, safety, and cost-effectiveness. However, the polyiodide shuttling results in serious active mass loss and Zn corrosion, which limits the cycling life of Zn-I2 batteries. Inspired by the chromogenic reaction between starch and iodine, a structure confinement strategy is proposed to suppress polyiodide shuttling in Zn-I2 batteries by hiring starch, due to its unique double-helix structure. In situ Raman spectroscopy demonstrates an I5 - -dominated I- /I2 conversion mechanism when using starch. The I5 - presents a much stronger bonding with starch than I3 - , inhibiting the polyiodide shuttling in Zn-I2 batteries, which is confirmed by in situ ultraviolet-visible spectra. Consequently, a highly reversible Zn-I2 battery with high Coulombic efficiency (≈100% at 0.2 A g-1 ) and ultralong cycling stability (>50 000 cycles) is realized. Simultaneously, the Zn corrosion triggered by polyiodide is effectively inhibited owing to the desirable shuttling-suppression by the starch, as evidenced by X-ray photoelectron spectroscopy analysis. This work provides a new understanding of the failure mechanism of Zn-I2 batteries and proposes a cheap but effective strategy to realize high-cyclability Zn-I2 batteries.

15.
Huan Jing Ke Xue ; 43(4): 1958-1965, 2022 Apr 08.
Artigo em Chinês | MEDLINE | ID: mdl-35393819

RESUMO

Lakes play an important role in the biogeochemical cycling of dissolved organic matter (DOM) and the emission of methane (CH4). We investigated the concentration and effluxes of CH4 and then analyzed the corresponding driving factors in Lake Luoma, a key lake along the South-to-North Water Transfer Project. Our results indicated that Lake Luoma was a hotspot of CH4 emissions with an annual mean concentration and efflux of (0.12±0.09) µmol·L-1 and (21.0±18.5) mmol·(m2·d)-1, respectively. We found higher mean CH4 levels in the wet season than those in the dry season and further higher levels than those in the wet-to-dry transition season. Spatially, the CH4 efflux was higher in the northwest inflowing regions and lower in the southeast outflow regions. The variability in annual CH4 efflux was affected by a combination of water temperature and hydrological conditions. Terrestrial input of dissolved organic carbon (DOC) and chromophoric DOM (CDOM) had fueled the production of CH4 by providing necessary carbon substrates, and four PARAFAC DOM components were identified including a microbial humic-like C1, a tryptophan-like C2, a terrestrial humic-like C3, and a tyrosine-like C4. The CH4 efflux from the lake was significantly promoted by the input and accumulation of terrestrial humic-like components, and Chl-a had no correlation with CH4 efflux, suggesting that algal degradation was not directly fueling the emission of CH4. Lake Luoma had been significantly disturbed by human activities, and terrestrial input of nutrient loading (TN and TP) into the lake not only improved the productivity and trophic level of the water body but also enhanced the production and release of CH4 from the surface water. We concluded that the CH4 emissions in Lake Luoma can be influenced by the combination of environmental factors, CDOM composition, and nutrient level. Long-term observation is needed for better evaluation of the driving factors in fueling the emission of CH4 so as to effectively reduce the emissions of CH4 and other greenhouse gases by taking corresponding countermeasures.


Assuntos
Lagos , Metano , Matéria Orgânica Dissolvida , Humanos , Lagos/química , Espectrometria de Fluorescência , Água
16.
Huan Jing Ke Xue ; 43(8): 4118-4126, 2022 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-35971709

RESUMO

Nitrous oxide (N2O) is one of the six greenhouse gases stipulated in the Kyoto Protocol. Its greenhouse potential over the past century was 298 times that of CO2, and the concentration of atmospheric N2O has been continuously and rapidly increasing during the past hundred years. Shallow lakes are an important source of atmospheric N2O. In order to explore the temporal and spatial changes and potential driving factors of N2O emissions from eutrophic water, we conducted field observations in February (winter) and August (summer) in Lake Taihu. We used the coefficient of diffusion-headspace bottle method to trace the variability in the N2O concentration[c(N2O)] and efflux[F(N2O)] from surface water bodies and explored the potential driving factors of N2O emissions. The optical measurements of dissolved organic matter (DOM) are an effective approach for tracing the source and composition of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON). The migration and transformation processes of DOM also release a large amount of inorganic nitrogen, which changes the redox potential of the water column and thereby affects N2O emissions. Our results showed that the variability in c(N2O) and F(N2O) in the surface waters of Lake Taihu were strongly affected by water temperature and nutrient levels. The average c(N2O) of the surface waters was (19.7±2.7) nmol·L-1, corresponding to a mean F(N2O) of (41.1±1.8) µmol·(m2·d)-1, and the means of both c(N2O) and F(N2O) were higher in summer than those in winter (t-test, P<0.01). The input and accumulation of DOM could increase the production and emission potential of N2O in water bodies, as supported by both c(N2O) and F(N2O) significantly increasing with increasing level of terrestrial humic-like C1. The integration ratio of peak C to peak T IC:IT of DOM and the spectral slope S275-295 results indicated that there were high inputs of terrestrial DOM in the northwestern inflowing river mouths, concurring with the high production and emission of N2O found there. This suggested that the accumulation and degradation of terrestrial DOM potentially fueled the emission of N2O. Our results showed that water temperature, DOM composition, and nutrient level were all important factors affecting N2O emission from Lake Taihu. Long-term continuous observation can be applied to better evaluate the impact of various environmental factors on the production and emission of N2O in water bodies and to help with providing scientific emission reduction plans.


Assuntos
Lagos , Óxido Nitroso , China , Óxido Nitroso/análise , Rios , Estações do Ano , Água
17.
Huan Jing Ke Xue ; 43(2): 826-836, 2022 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-35075856

RESUMO

Lake Qinghai is the largest lake in China and is of great significance to maintain the ecological security of the Qinghai-Tibet Plateau. Few studies have been carried out to investigate the optical composition and source of chromophoric dissolved organic matter (CDOM) in large lakes on the Qinghai-Tibet Plateau. It is of great significance to study the source and optical dynamics of CDOM in Lake Qinghai watershed for water quality protection and filling in the gaps in the knowledge of CDOM variability in a remote area. Two sampling campaigns in the Lake Qinghai watershed were carried out, and excitation-emission matrices coupled with parallel factor analysis (EEMs-PARAFAC) were used to unravel the optical composition and the sources of CDOM. Our results indicated that the mean dissolved organic carbon (DOC) concentration, a250:a365, and the spectral slope of CDOM absorption S275-295 in the lake were significantly higher than that in the inflow river (P<0.0001, t-test), whereas the mean absorption coefficient of CDOM a350, humification index (HIX), fluorescence peak integration ratio IC:IT, and specific ultraviolet absorbance at 254 nm SUVA254 of CDOM were shown to be lower in the lake than in the inflow river (P<0.0001), indicating that compared with the lake itself, CDOM in the inflow was humic-rich and highly aromatic. Four fluorescent components were obtained using PARAFAC, including a terrestrial human-like component C1, a microbial human-like component C2, a tyrosine-like C3, and a tryptophan-like C4. The mean DOC concentration, S275-295, and a250:a365in the headwater streams of the Lake Qinghai watershed were lower than those in the downstream estuary, indicating that the CDOM abundance increased, and the molecular weight decreased, from the headwaters to the downstream river mouths. The mean of SUVA254, C1, and the first axis of principal component analysis were positively related to terrestrial input (i.e., the PC1 values were significantly higher in rivers than in lakes (P<0.001)), indicating that the aromaticity of CDOM in rivers was higher than that in lakes. Particularly, the contribution of terrestrial humic-like C1 was higher in the Quanji River, Shaliu River, and Khargai River compared with that in other tributaries due to an intensified cultivated land use at the downstream estuary of these rivers.


Assuntos
Matéria Orgânica Dissolvida , Lagos , China , Humanos , Rios , Espectrometria de Fluorescência , Qualidade da Água
18.
Comput Struct Biotechnol J ; 20: 2442-2454, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35602976

RESUMO

Cathepsin L (CTSL), a cysteine protease that can cleave and activate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein, could be a promising therapeutic target for coronavirus disease 2019 (COVID-19). However, there is still no clinically available CTSL inhibitor that can be used. Here, we applied Chemprop, a newly trained directed-message passing deep neural network approach, to identify small molecules and FDA-approved drugs that can block CTSL activity to expand the discovery of CTSL inhibitors for drug development and repurposing for COVID-19. We found 5 molecules (Mg-132, Z-FA-FMK, leupeptin hemisulfate, Mg-101 and calpeptin) that were able to significantly inhibit the activity of CTSL in the nanomolar range and inhibit the infection of both pseudotype and live SARS-CoV-2. Notably, we discovered that daptomycin, an FDA-approved antibiotic, has a prominent CTSL inhibitory effect and can inhibit SARS-CoV-2 pseudovirus infection. Further, molecular docking calculation showed stable and robust binding of these compounds with CTSL. In conclusion, this study suggested for the first time that Chemprop is ideally suited to predict additional inhibitors of enzymes and revealed the noteworthy strategy for screening novel molecules and drugs for the treatment of COVID-19 and other diseases with unmet needs.

19.
BMC Med Genomics ; 15(1): 144, 2022 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-35765053

RESUMO

BACKGROUND: Methamphetamine (METH) abuse causes serious health problems, including injury to the immune system, leading to increased incidence of infections and even making withdrawal more difficult. Of course, immune cells, an important part of the immune system, are also injured in methamphetamine abuse. However, due to different research models and the lack of bioinformatics, the mechanism of METH injury to immune cells has not been clarified. METHODS: We examined the response of three common immune cell lines, namely Jurkat, NK-92 and THP-1 cell lines, to methamphetamine by cell viability and apoptosis assay in vitro, and examined their response patterns at the mRNA level by RNA-sequencing. Differential expression analysis of two conditions (control and METH treatment) in three types of immune cells was performed using the DESeq2 R package (1.20.0). And some of the differentially expressed genes were verified by qPCR. We performed Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis of differentially expressed genes by the clusterProfiler R package (3.14.3). And gene enrichment analysis was also performed using MetaScape ( www.metascape.org ). RESULTS: The viability of the three immune cells was differentially affected by methamphetamine, and the rate of NK-cell apoptosis was significantly increased. At the mRNA level, we found disorders of cholesterol metabolism in Jurkat cells, activation of ERK1 and ERK2 cascade in NK-92 cells, and disruption of calcium transport channels in THP-1 cells. In addition, all three cells showed changes in the phospholipid metabolic process. CONCLUSIONS: The results suggest that both innate and adaptive immune cells are affected by METH abuse, and there may be commonalities between different immune cells at the transcriptome level. These results provide new insights into the potential effects by which METH injures the immune cells.


Assuntos
Metanfetamina , Ontologia Genética , Humanos , Metanfetamina/efeitos adversos , RNA Mensageiro/genética , Análise de Sequência de RNA , Transcriptoma
20.
Chem Commun (Camb) ; 58(15): 2488-2491, 2022 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-35084422

RESUMO

We synthesized Cu single atoms embedded in a N-doped porous carbon catalyst with a high Faradaic efficiency of 93.5% at -0.50 V (vs. RHE) for CO2 reduction to CO. The evolution of Cu single-atom sites to nanoclusters of about 1 nm was observed after CO2 reduction at a potential lower than -0.30 V (vs. RHE). The DFT calculation indicates that Cu nanoclusters improve the CO2 activation and the adsorption of intermediate *COOH, thus exhibiting higher catalytic activity than CuNx sites. The structural instability observed in this study helps in understanding the actual active sites of Cu single atom catalysts for CO2 reduction.

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