Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Adv Sci (Weinh) ; 11(13): e2305818, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38240578

RESUMEN

Current metagenome assembled human gut phage catalogs contained mostly fragmented genomes. Here, comprehensive gut virome detection procedure is developed involving virus-like particle (VLP) enrichment from ≈500 g feces and combined sequencing of short- and long-read. Applied to 135 samples, a Chinese Gut Virome Catalog (CHGV) is assembled consisting of 21,499 non-redundant viral operational taxonomic units (vOTUs) that are significantly longer than those obtained by short-read sequencing and contained ≈35% (7675) complete genomes, which is ≈nine times more than those in the Gut Virome Database (GVD, ≈4%, 1,443). Interestingly, the majority (≈60%, 13,356) of the CHGV vOTUs are obtained by either long-read or hybrid assemblies, with little overlap with those assembled from only the short-read data. With this dataset, vast diversity of the gut virome is elucidated, including the identification of 32% (6,962) novel vOTUs compare to public gut virome databases, dozens of phages that are more prevalent than the crAssphages and/or Gubaphages, and several viral clades that are more diverse than the two. Finally, the functional capacities are also characterized of the CHGV encoded proteins and constructed a viral-host interaction network to facilitate future research and applications.


Asunto(s)
Bacteriófagos , Humanos , Bacteriófagos/genética , Análisis de Secuencia , Genoma Viral/genética , Metagenoma/genética , Heces
2.
Small ; 20(4): e2305879, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37715100

RESUMEN

Central metal exchange can innovatively open the cavity of metal-organic frameworks (MOFs) by alternating the framework topology. Here, the single-crystal-to-single-crystal (SC-SC) transformation is reported from a Co-based MOF {[Co1.25 (HL)0.5 (Pz-NH2 )0.25 (µ3 -O)0.25 (µ2 -OH)0.25 (H2 O)]·0.125 Co·0.125 L·10.25H2 O}n (Co-MOF, L = 5,5'-(1H-2,3,5-triazole-1,4-diyl)diisophthalic acid) into two novel MOF materials, {[Cu1.75 L0.75 (Pz-NH2 )0.125 (µ3 -O)0.125 (µ2 -OH)0.25 (H2 O)0.375 ]•3CH3 CN}n (Cu-MOF) and {[Zn1.75 L0.625 (Pz-NH2 )0.25 (µ3 -O)0.25 (µ2 -O)0.25 (H2 O)1.25 ]•4CH3 CN}n (Zn-MOF), through exchanging the Co2+ in the MOF into Cu2+ or Zn2+ , respectively. The free Co2+ and L4- in the Co-MOF channels fuse with the skeleton during the Co→Cu and Co→Zn exchange processes, leading to the expansion of the channel space and the transformation of the secondary building units (SBUs) to form an adjustable skeleton. The nonlinear optical response results show that the MOFs generated by the exchange of the central metal exhibit different saturable absorption and the self-focusing effect. In addition, loading polypyrrole (PPy) into the MOFs can not only improve the stability of the MOFs but also further optimize the nonlinear optical behavior. This work suggests that SC-SC central metal exchange and the introduction of polymer molecules can tune the nonlinear optical response, which provides a new perspective for the future study of nonlinear optical materials.

3.
Gut Microbes ; 15(1): 2205386, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37140125

RESUMEN

Cross-cohort validation is essential for gut-microbiome-based disease stratification but was only performed for limited diseases. Here, we systematically evaluated the cross-cohort performance of gut microbiome-based machine-learning classifiers for 20 diseases. Using single-cohort classifiers, we obtained high predictive accuracies in intra-cohort validation (~0.77 AUC), but low accuracies in cross-cohort validation, except the intestinal diseases (~0.73 AUC). We then built combined-cohort classifiers trained on samples combined from multiple cohorts to improve the validation of non-intestinal diseases, and estimated the required sample size to achieve validation accuracies of >0.7. In addition, we observed higher validation performance for classifiers using metagenomic data than 16S amplicon data in intestinal diseases. We further quantified the cross-cohort marker consistency using a Marker Similarity Index and observed similar trends. Together, our results supported the gut microbiome as an independent diagnostic tool for intestinal diseases and revealed strategies to improve cross-cohort performance based on identified determinants of consistent cross-cohort gut microbiome alterations.


Asunto(s)
Microbioma Gastrointestinal , Humanos , Microbioma Gastrointestinal/genética , Aprendizaje Automático , Proyectos de Investigación , Metagenoma , Metagenómica/métodos
4.
Cell Cycle ; 22(21-22): 2467-2484, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-38179789

RESUMEN

Pathological cardiac hypertrophy (referred to as cardiac hypertrophy) is a maladaptive response of the heart to a variety of pathological stimuli, and cardiac hypertrophy is an independent risk factor for heart failure and sudden death. Currently, the treatments for cardiac hypertrophy are limited to improving symptoms and have little effect. Elucidation of the developmental process of cardiac hypertrophy at the molecular level and the identification of new targets for the treatment of cardiac hypertrophy are crucial. In this review, we summarize the research on multiple active substances related to the pathogenesis of cardiac hypertrophy and the signaling pathways involved and focus on the role of transforming growth factor-ß (TGF-ß) and bone morphogenetic protein (BMP) signaling in the development of cardiac hypertrophy and the identification of potential targets for molecular intervention. We aim to identify important signaling molecules with clinical value and hope to help promote the precise treatment of cardiac hypertrophy and thus improve patient outcomes.


Asunto(s)
Transducción de Señal , Factor de Crecimiento Transformador beta , Humanos , Factor de Crecimiento Transformador beta/metabolismo , Cardiomegalia , Proteínas Morfogenéticas Óseas/metabolismo , Factores de Crecimiento Transformadores , Proteína Morfogenética Ósea 2
5.
PeerJ ; 10: e14584, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36540806

RESUMEN

Phosphorus starvation response (PHR) protein is an important transcription factor in phosphorus regulatory network, which plays a vital role in regulating the effective utilization of phosphorus. So far, the PHR genes have not been systematically investigated in cotton. In the present study, we have identified 22, 23, 41 and 42 PHR genes in G. arboreum, G. raimondii, G. hirsutum and G. barbadense, respectively. Phylogenetic analysis showed that cotton PHR genes were classified into five distinct subfamilies. The gene structure, protein motifs and gene expression were further investigated. The PHR genes of G. hirsutum from the same subfamily had similar gene structures, all containing Myb_DNA-binding and Myb_CC_LHEQLE conserved domain. The structures of paralogous genes were considerably conserved in exons number and introns length. The cis-element prediction in their promoters showed that genes were not only regulated by light induction, but also were related to auxin, MeJA, abscisic acid-responsive elements, of which might be regulated by miRNA. The expression analysis showed that the GhPHR genes were differentially expressed in different tissues under various stresses. Furthermore, GhPHR6, GhPHR11, GhPHR18 and GhPHR38 were significantly changed under low phosphorus stress. The results of this study provide a basis for further cloning and functional verification of genes related to regulatory network of low phosphorus tolerance in cotton.


Asunto(s)
Factores de Transcripción , Filogenia , Factores de Transcripción/genética , Intrones/genética
6.
Front Cardiovasc Med ; 9: 1066065, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36440039

RESUMEN

A young man repeatedly found a right atrial mass with severe wheezing and extreme dyspnea. His condition was critical and complicated. The process of correct diagnosis was full of twists and turns. Finally, he got better and was discharged from the hospital after anticoagulation therapy, which suggested that correct clinical thinking and decision are particularly important in the process of diagnosis and treatment.

7.
Dalton Trans ; 51(30): 11231-11235, 2022 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-35880646

RESUMEN

A novel metal-organic framework (MOF) host-guest material [Cd3(EtOIPA)4(HAD)2]·H2O has been successfully synthesized by the reaction of 5-ethoxyisophthalic acid (EtOIPA), acridine (AD) and Cd(II) salts under hydrothermal conditions. Structurally, the title MOF possesses a trinucleate Cd(II) based 2D double-layer with the protonated AD cations as the template encapsulated into the grids. The combination of experiments and theoretical calculations reveals that the orderly arrangement of EtOIPA dimers, protonated AD cations and trinucleate Cd(II) clusters generates highly delocalized π-electron channels with a prolonged exciton lifetime. The MOF powders show bright yellow emission with a long lifetime of 50.63 ns. Photoelectrochemical measurements reveal a high photocurrent density ratio of 290 between light and dark conditions at 0 V bias potential, making it a perfect self-driven photodetector. By coating the yellow phosphor on a commercially available blue LED, a high performance white LED with CIE, CCT and CRI values of (0.325, 0.336), 88.2 and 5844 K, respectively can be obtained.

8.
Zhongguo Yi Liao Qi Xie Za Zhi ; 46(1): 47-51, 2022 Jan 30.
Artículo en Chino | MEDLINE | ID: mdl-35150107

RESUMEN

In order to effectively prevent the damage to the human body caused by abnormal oxygen concentration in the medical hyperbaric oxygen chamber, a ZigBee-based medical hyperbaric oxygen chamber oxygen concentration automatic control system is designed. The data acquisition module uses the microprocessor STM32F103C8T6 to receive the oxygen concentration data of each acquisition point, and the ZigBee of the data processing module transmits the processing results to the MSP430G2553 single-chip microcomputer at the receiving end of the slave. The MSP430G2553 single-chip microcomputer uses a self-organizing TS fuzzy neural network (SOTSFNN) and adds activation. The intensity concept realizes automatic control of the oxygen concentration in the hyperbaric oxygen chamber, and controls the buzzer to give an alarm when the oxygen concentration is lower than 19 mg/L and higher than 23 mg/L, and displays the current real-time oxygen concentration through LCD12864. The experimental results show that as the communication distance increases, the packet loss rate of the system is always lower than 5%, and the signal strength under the same communication distance is better; the system can effectively control the oxygen concentration value within the set range, and the oxygen concentration. The control accuracy is high and the stability is good.


Asunto(s)
Oxigenoterapia Hiperbárica , Humanos , Microcomputadores , Oxígeno
9.
Inorg Chem ; 60(24): 18593-18597, 2021 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-34822244

RESUMEN

The relationship between the aggregation states of pyrene-based linkers and the photoluminescence/photoelectric performance was well studied by the formation of an anionic metal-organic framework, [BMI]2[Mg3(TBAPy)2(H2O)4]·2dioxane, which shows highly enhanced light-harvesting and photoelectric conversion efficiency by the encapsulation of D-π-A cation dyes.

10.
Chemistry ; 27(15): 5011-5018, 2021 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-33438786

RESUMEN

A 3D Co-based metal-organic framework (Co-MOF) with two kinds of large pores filled by free Co2+ ions and ligands was synthesized and characterized. To expand the MOF structure and conductivity, the free Co2+ ions and ligands were exchanged by conductive ionic liquid EtpyBr and photosensitive AgNO3 through single crystal-to-single crystal transformation, which produced structure-changed 3D MOFs Co-MOF-Br and Co-Ag-MOF, which were characterized by single-crystal X-ray diffraction. Incorporating small quantities of doped polyaniline (PANI) with redox activity into the pores could further tune the stability and conductivity of the three MOFs. The PANI/MOFs all show outstanding electrical conductivity (≈10-2  S cm-1 ), and PANI/Co-MOF-Br has the largest p-type Seebeck coefficient of 66.6 µV K-1 . PANI/Co-MOF-Br and PANI/Co-Ag-MOF have 4 and 15 times higher photocurrent density compared with PANI/Co-MOF, respectively. This work sheds light on the design of advanced electrically conductive 3D MOFs.

11.
Int J Biol Macromol ; 149: 901-907, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-32007550

RESUMEN

Black soldier fly can convert organic wastes into their own functional biological macromolecules i.e. chitin that has great potential for biotechnological, biomedical and cosmetic application. The variation in the physiochemical structure of chitin was proved for several insects during metamorphosis stages whereas, it remains unknown for black soldier fly (BSF), a recognized resource insect for industrial production and organic waste management. The current work noted results on how the chitin matrix can undergo physicochemical changes during the developmental phases (larvae, prepupa, puparium, and adults) of BSF. Chitin content was determined around 3.6%, 3.1%, 14.1% and 2.9%, respectively. Fourier transform infrared spectroscopy, thermogravimetric analysis and x-ray diffraction analysis showed that chitin from BSF different stages was all α-chitin with similar thermal stability. The chitin crystalline index increased gradually with development from larvae to adult, 33.09%, 35.14%, 68.44% and 87.92%, respectively. Moreover, it was observed by scan electron microscopy that surface morphology characteristics of chitin vary significantly in developmental phases. These results confirmed that Hermetia illucens is promising for converting organic wastes into valuable biopolymers i.e. chitin and its physiochemical properties in various developmental stages help to determine the related biomedical, biotechnological, cosmetic and functional food utilization potential.


Asunto(s)
Fenómenos Químicos , Quitina/química , Estructura Molecular , Simuliidae/metabolismo , Animales , Biopolímeros , Biotransformación , Quitina/metabolismo , Larva , Simuliidae/embriología , Espectroscopía Infrarroja por Transformada de Fourier , Termogravimetría , Difracción de Rayos X
12.
RSC Adv ; 10(3): 1439-1446, 2020 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-35494702

RESUMEN

An alkali-resistant Zn-MOF directed by [BMI]Br ionic liquid, (BMI)2[Zn3(ptptc)2] (1), based on a π-electron-rich terphenyl-tetracarboxylic acid, has been synthesized under the combination of hydro/solvothermal and ionothermal condition (BMI = 1-butyl-3-methylimidazolium, H4ptptc = p-terphenyl-3,3'',5,5''-tetracarboxylic acid). In 1, the trinuclear Zn(ii) clusters are linked by the organic moieties of the ptptc ligands, resulting in a 3D anionic framework structure with highly disordered [BMI]+ cations filled in the pores. 1 exhibits good chemical stability in water and NaOH solutions (pH range of 7-12), which allow it to detect antibiotics and nitroaromatic explosives in an aquatic system. 1 represents high fluorescence quenching efficiency toward NFs (furazolidone, FZD; nitrofurazone, NZF; nitrofurantoin, NFT), NMs (ronidazole, RDZ; metronidazole, MDZ; dimetridazole, DTZ; ornidazole, ODZ) and nitrophenol (2-nitrophenol, 2-NP; 3-nitrophenol, 3-NP; 4-nitrophenol, 4-NP; 2,4,6-trinitrophenol, TNP) in water solution, respectively.

13.
Dalton Trans ; 47(1): 13-22, 2017 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-29177298

RESUMEN

Incorporating photosensitive molecules into the organic/inorganic hybrid materials can contribute to forming photoresponsive systems. The second/third-order nonlinear optical properties can be changed via external light stimulation at an appropriate wavelength. The photochromic metal complexes appear to be superior promising materials in the domain of photoswitchable nonlinear optics (NLO). Thus, the purpose of this review is to examine current progress of metal complexes in the field of photoswitchable NLO materials and provide perspectives for the future. The overview includes the second-order and third-order NLO photoswitches and NLO properties of metal complexes. Combined with the characteristics of pyrene and stilbazolium groups, we describe a new type of photoswitchable NLO materials. The rapidly increasing investigations in this domain suggest that NLO photoswitches of metal complexes would play a critical role for inspiring applications in the future.

14.
Dalton Trans ; 46(44): 15434-15442, 2017 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-29082391

RESUMEN

Two pH-stable luminescent metal-organic frameworks (LMOFs), {[Ln2(L)2(OH)(HCOO)]·[H2O]}n (Ln = Eu 1, Tb 2), based on a new π-conjugated organic building block involving both carboxylate and terpyridine groups were rationally synthesized under a combination of hydro/solvothermal and ionothermal conditions (H2L = 4'-(4-(3,5-dicarboxylphenoxy)phenyl)-4,2':6',4''-terpyridine). 1 and 2 are isostructural and feature noninterpenetrated open 3D condensed frameworks constructed by rod-shaped lanthanide-carboxylate building units. Their excellent water-stability and pH-stability allow them to be used in aquatic systems. 1 and 2 both exhibit selective and sensitive aqueous phase detection of the well-known nitroaromatic explosive environmental pollutant 2,4,6-trinitrophenol (TNP), which is highly desirable for practical applications. The presence of a free pyridine group on the LMOF particle surface was strategically utilized for the purpose of exclusive TNP-sensing.

15.
Dalton Trans ; 45(32): 12710-6, 2016 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-27443408

RESUMEN

Eleven water-stable isostructural mono/bimetallic lanthanide coordination polymers (Ln-CPs) {[EuxTb1-x (HL)(H2O)3]·H2O}n (x = 1.0 (1), 0.9 (3), 0.8 (4), 0.7 (5), 0.6 (6), 0.4 (7), 0.3 (8), 0.2 (9), 0.1 (10), 0.05 (11), 0 (2), H4L = 5,5'-(1H-2,3,5-triazole-1,4-diyl)diisophthalic acid) with uncoordinated Lewis basic triazole sites within the pores were prepared. The Ln-CPs represented by 1 showed a rapid and drastic emission quenching induced by external Fe(3+) and Cr(3+) cations and CrO4(2-) and CO3(2-) anions in aqueous solution. In addition, because of the comparable emission intensities of Eu(3+) and Tb(3+) ions, bimetallic CP 8 can be used as a ratiometric luminescent sensor for organic solvent molecules. Moreover, the luminescent color of the 8 sensor in pyridine and in other guest solvents undergoes obvious changes that can be clearly distinguished by the naked eye.

16.
Dalton Trans ; 45(18): 7776-85, 2016 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-27063339

RESUMEN

The rigid and planar tetracarboxylic acid 5,5'-(1H-2,3,5-triazole-1,4-diyl)diisophthalic acid (H4L), incorporating a triazole group, has been used with no or different pyridine-based linkers to construct a family of d(10) coordination polymers, namely, {[H2N(CH3)2]3[Cd3(L)2(HCOO)]}n (), {[Cd2(L)(py)6]·H2O}n (), {[H2N(CH3)2] [Cd2(L)(HCOO)(H2O)4]}n (), {[Zn(H2L)]·H2O}n (), and {[Zn(H2L)(4,4'-bipy)0.5]·C2H5OH·H2O}n () (py = pyridine, 4,4'-bipy = 4,4'-bipyridine). constructs a 3D porous network containing two kinds of channels: one is filled with coordinated HCOO(-) anions, and the other with [H2N(CH3)2](+) cations. The framework of can be described as a rare (5,6,7)-connected net with the Schläfli symbol of (4(12)·5·6(2))(4(5)·5(3)·6(2))2(4(8)·5(3)·6(8)·8(2))2. The Cd(ii) ions in are connected through the carboxylate ligands to form a 2D layer, with aperture dimensions of ∼15.1 Å × 16.2 Å. The network of features a 3D (3,4)-connected (6·8·10)2(6·8(3)·10(2)) topology. A 3D network with the (4(2)·6·8(3)) topology of possesses an open 1D channel with the free volume of 29.2%. is a 2D layer structure with the (4(2)·6(3)·8)(4(2)·6) topology. The fluorescence lifetime τ values of are on the nanosecond timescale at room temperature. In particular, central-metal exchange in leads to a series of isostructural M(ii)-Cd frameworks [M = Cu (), Co (), Ni ()] showing improved catalytic activity for the synthesis of 1,4,5,6-tetrahydropyrimidine derivatives. Based on this, a plausible mechanism for the catalytic reaction has been proposed and the reactivity-structure relationship has been further clarified.

17.
Chemistry ; 22(18): 6389-96, 2016 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-26997347

RESUMEN

Different morphologies and particle sizes of two crystalline zinc-based coordination polymers (CPs), [Zn(pytz)H2 O]n (1; H2 pytz=2,6-bis(tetrazole)pyridine) and [Zn2 (pytz)2 4 H2 O] (2), from the bulk scale to the nanoscale, could be obtained under solvothermal conditions with different surfactants (polyvinylpyrrolidone (PVP) or polyethylene glycol (PEG) 2000) as templates. PVP and PEG 2000 could act as capping and structure-directing agents, respectively, to influence the growth of crystalline particles and control their sizes. CP 1 exhibits a two-dimensional framework with window-like units and 2 shows a bimetallic structure. Nanocrystalline 1 and 2 were used as heterogeneous catalysts to study how adjacent catalytic active sites synergistically effected their catalytic reactivities in the direct catalytic conversion of aromatic dinitriles into oxazolines. The results showed that 1 produced bis-oxazolines as the sole products, whereas 2 gave the mono-oxazolines as the major products under the same reaction conditions.

18.
Dalton Trans ; 44(40): 17639-51, 2015 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-26394243

RESUMEN

Seven Mn(ii) coordination polymers, namely {[Mn2(ptptp)Cl2(H2O)3]·H2O}n (1), {[Mn(µ-ptptp)3]2[Mn3(µ3-Cl)]2}·2Cl·16H2O (2), {[Mn2(ptptp)(ip)2(H2O)3]·H2O}n (3), {[Mn2(ptptp)(5-CH3-ip)2(H2O)3]·H2O}n (4), {[Mn4(ptptp)(5-Br-ip)3(H2O)3]·4H2O}n (5), {[Mn2(ptptp)(Hbtc)(H2O)2]·2H2O}n (6) and {[Mn2(ptptp)(tdc)(H2O)2]·1.5H2O}n (7), have been prepared based on multidentate N-heterocyclic aromatic ligands and bridging carboxylate ligands (H2ptptp = 2-(5-{6-[5-(pyrazin-2-yl)-1H-1,2,4-triazol-3-yl]pyridin-2-yl}-1H-1,2,4-triazol-3-yl)pyrazine; R-isophthalic acids, H2ip-R: R = -H (3), -CH3 (4), -Br (5); H3btc = trimesic acid (6); H2tdc = thiophene-2,5-dicarboxylic acid (7)), in order to further probe the multiple roles of [RMI]Br ionic liquids in the hydro/solvothermal synthesis (RMI = 1-alkyl-3-methylimidazolium, R = ethyl, or propyl, or butyl). The successful syntheses of complexes 2-6 suggest that in hydro/solvothermal synthesis the addition of a small amount of [RMI]Br plays a crucial role. Complex 1 exhibits single right-handed helices constructed by ptptp ligands and Mn(ii) ions. Complex 2 possesses octanuclear helicate structures in which two propeller-shaped [Mn(µ-ptptp)3](4-) units embrace two [Mn3(µ3-Cl)](5+) cluster cores inside. Complexes 3 and 4 are isostructural and display a 1D double chain formed by two kinds of pseudo meso-helices: (Mn-ptptp)n and (Mn-5-R-ip)n. Complex 5 has a 2D structure containing 1D Mn(ii) ion chains formed through carboxylates and [ptptp](2-)-N,N bridges. Complex 6 shows a 2D structure formed by a meso-helix (Mn-ptptp)n and the partly deprotonated Hbtc ligands. Complex 7 features a heterochiral [2 + 2] coaxially nested double-helical column formed by using the outer double-helices (Mn-ptptp)n as a template to encapsulate the inner double-helices (Mn-tdc)n with opposite orientation. All complexes were characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, single-crystal X-ray crystallography and powder X-ray diffraction. The magnetic properties of 1-7 were also investigated.

19.
Dalton Trans ; 44(28): 12832-8, 2015 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-26101807

RESUMEN

A series of 2D layered isostructural coordination complexes {[M3(L)2(H2O)6]·H2O}n (M = Mn (1), Mn0.7Co0.3 (2), Mn0.5Co0.5 (3), Mn0.3Co0.7 (4), and Co (5), respectively, H3L = 1-aminobenzene-3,4,5-tricarboxylic acid) have been synthesized under hydrothermal conditions, and applied to catalyze the reaction of degenerating organic dyes under visible light irradiation. The photocatalytic results indicate that complex 5 exhibits good photocatalytic properties in the presence of H2O2, while 1 can restrain the photodegradation of organic dyes. Remarkably, when Mn ions are gradually replaced by Co ions in the complexes, the photocatalytic activities of 1­5 turn from inhibition to promotion, which is a controllable regulation of photocatalytic properties via changing metal ions. Moreover, by using novel magnetic analysis methods and diffuse-reflectance UV/Vis spectra analysis methods, we explain the influence of central metal ions on the photocatalytic performance.

20.
Appl Opt ; 47(11): 1718-28, 2008 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-18404168

RESUMEN

The iterative projection method, originally proposed by Kaczmarz and Cimmino, was recently applied to particle size analysis with forward light scattering. Modification was made to improve the convergent procedure. However, there are still limitations. It is found that the solutions are oscillatory when the method is applied to a set of underdetermined linear equations without any additional constraints. A new version of the projection method, combined with the constraints of nonnegativity and smoothness, is proposed and is studied in the presence of experimental noise. Compared with the early versions of the projection method, this one shows fast convergence, is more stable against random noise, and is insensitive to particle size distributions.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...