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1.
PLoS Negl Trop Dis ; 16(1): e0010136, 2022 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-35030167

RESUMO

BACKGROUND: As China is moving onto schistosomiasis elimination/eradication, diagnostic methods with both high sensitivity and specificity for Schistosoma japonicum infections in humans are urgently needed. Microscopic identification of eggs in stool is proven to have poor sensitivity in low endemic regions, and antibody tests are unable to distinguish between current and previous infections. Polymerase chain reaction (PCR) technologies for the detection of parasite DNA have been theoretically assumed to show high diagnostic sensitivity and specificity. However, the reported performance of PCR for detecting S. japonicum infection varied greatly among studies. Therefore, we performed a meta-analysis to evaluate the overall diagnostic performance of variable-temperature PCR technologies, based on stool or blood, for detecting S. japonicum infections in humans from endemic areas. METHODS: We searched literatures in eight electronic databases, published up to 20 January 2021. The heterogeneity and publication bias of included studies were assessed statistically. The risk of bias and applicability of each eligible study were assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool (QUADAS-2). The bivariate mixed-effects model was applied to obtain the summary estimates of diagnostic performance. The hierarchical summary receiver operating characteristic (HSROC) curve was applied to visually display the results. Subgroup analyses and multivariate regression were performed to explore the source of heterogeneity. This research was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and was registered prospectively in PROSPERO (CRD42021233165). RESULTS: A total of 2791 papers were retrieved. After assessing for duplications and eligilibity a total of thirteen publications were retained for inclusion. These included eligible data from 4268 participants across sixteen studies. High heterogeneity existed among studies, but no publication bias was found. The pooled analyses of PCR data from all included studies resulted in a sensitivity of 0.91 (95% CI: 0.83 to 0.96), specificity of 0.85 (95% CI: 0.65 to 0.94), positive likelihood ratio of 5.90 (95% CI: 2.40 to 14.60), negative likelihood ratio of 0.10 (95% CI: 0.05 to 0.20) and a diagnostics odds ratio of 58 (95% CI: 19 to 179). Case-control studies showed significantly better performances for PCR diagnostics than cross-sectional studies. This was further evidenced by multivariate analyses. The four types of PCR approaches identified (convention PCR, qPCR, Digital droplet PCR and nested PCR) differed significantly, with nested PCRs showing the best performance. CONCLUSIONS: Variable-temperature PCR has a satisfactory performance for diagnosing S. japonicum infections in humans in endemic areas. More high quality studies on S. japonicum diagnostic techniques, especially in low endemic areas and for the detection of dual-sex and single-sex infections are required. These will likely need to optimise a nested PCR alongside a highly sensitive gene target. They will contribute to successfully monitoring endemic areas as they move towards the WHO 2030 targets, as well as ultimately helping areas to achieve these goals.

2.
Spectrochim Acta A Mol Biomol Spectrosc ; 264: 120283, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34428635

RESUMO

In this work, we report in situ nonlinear microscopic images on plasmon-enhanced coherent anti-Stokes Raman scattering (CARS) and plasmon-Induced two-photon excited fluorescence (TPEF)of non-fluorescent microorganism. Our unique synthesized Au@Ag nanorods provide with two distinct surface-plasmon resonance (SPR) at 400 and 800 nm, respectively, which can efficiently induce linear fluorescence signals of E. coli but also enhance the nonlinear optical spectroscopy signals of TPEF, and coherent anti-Stokes Raman scattering (CARS) imaging of E. coli and S. aureus. Furthermore, calculations with complete active space self-consistent field (CASSCF) reveals the hot electrons of SPs can efficiently induce the biological fluorescence of non-fluorescent flavin nucleotides on the surface of E. coli. This novel mechanism is expected to guide the development and application of new microbial detection reagents. Gram-negative and Gram-positive bacteria can be well distinguished by nonlinear microscopic imaging of the CARS signal at 1589 cm-1. Benefit by the strong penetrability of non-linear optical signals, it is expected to realize in situ real-time detection and classification of pathogenic microbial infections in vivo.


Assuntos
Escherichia coli , Análise Espectral Raman , Fótons , Coloração e Rotulagem , Staphylococcus aureus
3.
Nanotechnology ; 33(13)2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34911057

RESUMO

Surface-enhanced Raman scattering (SERS) is recognized as one of the most favored techniques for enhancing Raman signals. The morphology of the SERS substrate profoundly affects molecular Raman spectra. This study aimed to construct a ring-mounted nanostructured substrate via liquid-liquid two-phase self-assembly incorporated with anodic aluminum oxide (AAO) membrane transfer techniques. High-density nanoparticles (NPs) assembled on AAO membranes were ascribed to reduce the diameters of the nanopores, with Au-Ag alloy NPs to regulate the dielectric constant so as to reveal the local surface plasmon resonance tunability. SERS engineered in this way allowed for the fabrication of a ring-mounted nanostructured substrate where the distribution density of NPs and dielectric constant could be independently fine-tuned. High SERS activity of the substrate was revealed by detecting the enhanced factor of crystal violet and rhodamine 6G molecules, which was up to 1.56 × 106. Moreover, SERS of thiram target molecules confirmed the supersensitivity and repeatability of the substrate as a practical application. The results of this study manifested a low-cost but high-efficiency ring-mounted nanostructured SERS substrate that might be suitable in many fields, including biosensing, medical research, environmental monitoring, and optoelectronics.

4.
Spectrochim Acta A Mol Biomol Spectrosc ; 265: 120360, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34509891

RESUMO

Plasmon has been widely investigated and applied, because it can greatly enhance molecular Raman spectral intensity. In this study, the resonance Raman effect of the tetra-tert-butylnaphthalocyanine (TTBN) is analyzed, including the Raman wave number shift and enhancement factor, resulting from light of different incident wavelengths. Furthermore, the optical properties of TTBN are obtained, such as charge transfer, the electronic circular dichroism (ECD) spectrum, etc. Lastly, we study the tip-enhanced Raman spectroscopy (TERS) by adjusting the parameters of the metal tip to achieve the highest electromagnetic enhancement at different incident wavelengths. Combining the resonance excitation effect and the tip enhanced Raman effect, the enhancement factor of TERS can reach up to 108-109. This study provides significant help for a profound understanding of the TERS mechanism.

5.
Nanomaterials (Basel) ; 11(12)2021 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-34947768

RESUMO

Carbon dots (CDs) are known as the rising star of carbon-based nanomaterials and, by virtue of their unique structure and fascinating properties, they have attracted considerable interest in different fields such as biological sensing, drug delivery, photodynamic therapy, photocatalysis, and solar cells in recent years. Particularly, the outstanding electronic and optical properties of the CDs have attracted increasing attention in biomedical and photocatalytic applications owing to their low toxicity, biocompatibility, excellent photostability, tunable fluorescence, outstanding efficient up-converted photoluminescence behavior, and photo-induced electron transfer ability. This article reviews recent progress on the synthesis routes and optical properties of CDs as well as biomedical and photocatalytic applications. Furthermore, we discuss an outlook on future and potential development of the CDs based biosensor, biological dye, biological vehicle, and photocatalysts in this booming research field.

6.
Mol Biol Rep ; 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34725747

RESUMO

BACKGROUND: Oncomelania hupensis hupensis is the only intermediate host of Schistosoma japonicum, the causative agent of schistosomiasis in China and is therefore of significant medical and veterinary health importance. Although tremendous progress has been achieved, there remains an understudied area of approximately 2.06 billion m2 of potential snail habitats. This area could be further increased by annual flooding. Therefore, an understanding of population genetics of snails in these areas may be useful for future monitoring and control activities. METHODS AND RESULTS: We sampled snails from Hexian (HX), Zongyang (ZY) and Shitai (ST) in Anhui (schistosomiasis transmission control), and from Hengtang (HT), Taicang (TC), Dongsan (DS) and Xisan (XS) in Jiangsu (schistosomiasis transmission interrupted), downstream of Anhui. ST, DS and XS are classified as hilly and mountainous areas, and HX, ZY, TC and HT as lake and marshland areas. The mitochondrial cytochrome c oxidase subunit I gene were sequenced. Out of 115 snails analyzed, 29 haplotypes were identified. We observed 56 (8.72%) polymorphic sites consisting of 51 transitions, four transversions and one multiple mutational change. The overall haplotype and nucleotide diversity were 0.899 and 0.01569, respectively. Snail populations in Anhui had higher genetic diversity than in Jiangsu. 73.32% of total variation was distributed among sites and 26.68% within sites. Snails were significantly separated according to eco-epidemiological settings in both network and phylogenetic analyses. CONCLUSION: Our results could provide important guidance towards assessing coevolutionary interactions of snails with S. japonicum, as well as for future molluscan host monitoring and control activities.

7.
Opt Express ; 29(22): 36857-36870, 2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34809086

RESUMO

It is great challenge and interesting for researchers to fabricate substrates for enhanced Raman and sensor, and assemble some easy-to-synthesize metallic nanomaterials into controllable nanostructures with special morphologies and arrangements, via alternating current (AC) electric field. The Au-Ag alloy nanoparticles (Au-Ag alloy NPs) colloidal suspension with excellent dispersibility synthesized by wet chemical method, and the morphology of the assembly can be well controlled by regulating the frequency of the AC electric field. Au-Ag alloy nanochains array (Au-Ag ANCs) with dense plasmonic "hot spots" is formed when the AC electric field of 4Vpp-30kHz is applied, which is supported by the result of finite element method (FEM) numerical simulation. Experimental results demonstrate that Au-Ag ANCs show excellent SERS activity: Au-Ag ANCs can detect both Rhodamine 6G (Rh6G) and crystal violet (CV) in the magnitude order of 10-10 M, and the Raman peaks intensity and analyte concentration has a strong linear correlation (R2 is 0.99339 and 0.95916, respectively). Besides, the introduction of Au-Ag ANCs makes the Raman spectra intensity of thiram (a pesticide) with a concentration of 30 ppm on the surface of the blank ITO glass significantly enhanced, and it can detect thiram with a concentration as low as 0.03 ppm. In addition, Au-Ag ANCs substrate exhibits great uniformity and stability, so they have considerable application potential in the field of quantitative detection of trace substances.

8.
Acta Trop ; 222: 106048, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34273315

RESUMO

Praziquantel (PZQ), the only choice of chemotherapy for schistosomiasis recommended by World Health Organization (WHO), has been widely used over 40 years. The long-term, and rapid expansion of, PZQ use for disease control across a large populations continues to raise concern regarding the potential for emergence and establishment of drug resistance. Recent research has also proposed that the long survival and low sensitivity of unpaired worms, derived from either incomplete treatment cure rates or single-sex schistosome infections within final hosts, could exacerbate the risk of PZQ resistance (PZQ-R) emerging. With the aim of assessing whether PZQ efficacy amongst S. japonicum may have changed over time in China, we performed a unique systematic review and meta-analyses on datasets which evaluated the efficacy of PZQ via laboratory assays of field S. japonicum isolates on experimental mice over time. Relevant published literatures from four electronic bibliographic databases and lists of article references were searched. Two indexes, d, a measure used in meta-analyses for worm burden difference between two groups, and r, a traditional measure for worm reduction percentage after treatment but without considering sample size were calculated for each study. A total of 25 papers including 127 experimental studies with eligible data on 2230 mice were retrieved. The pooled d (D) was 3.91 (3.56-4.25) and pooled r (R) was 54.52% (52.55%-56.52%). D significantly increased over time, whereas R non-significantly decreased; both estimates were significantly associated with the total drug dose. Such findings suggested no evidence of PZQ-R emergence S. japonicum to date. However, we consider the potential role of parasite origins, PZQ dosage, and single versus mixed gender infections of the results published to date, and the avenues now needed for further research.


Assuntos
Anti-Helmínticos , Praziquantel , Esquistossomose Japônica , Animais , Anti-Helmínticos/uso terapêutico , Resistência a Medicamentos , Camundongos , Praziquantel/uso terapêutico , Schistosoma japonicum , Esquistossomose Japônica/tratamento farmacológico
9.
Nanoscale ; 13(24): 10712-10725, 2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34128524

RESUMO

Tip-Enhanced Raman Spectroscopy (TERS) provides very high spatial resolution and detection sensitivity, so it has important applications in nano-scale molecular analysis. Plexciton is a polarization mode caused by a strongly coupled interaction between plasma excitons and excitons. It is a hot topic in plasma photonics research. We introduce the characteristics, production methods, observation methods and some applications of TERS. The electric field gradient (EFG) is an important factor affecting TERS resolution. The electron-phonon interaction is a fundamental inelastic interaction and plays an important role in current-carrying single-molecular junctions. This article summarizes the characteristics and applications of these three parts for readers to gain a preliminary understanding.

10.
Int J Parasitol ; 51(11): 887-891, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33905765

RESUMO

Schistosomiasis is caused by dioecious helminths of the genus Schistosoma. Recent work indicated that unpaired female and male schistosomes can survive within their definitive host for at least 1 year, although the viability or fertility of these worms after subsequent pairing remained untested. We performed two experiments on laboratory mice, one with female Schistosoma japonicum exposure first and male schistosomes second and another vice versa. After surviving as single-sex unpaired forms for up to 1 year, 58.5% of male and 70% of female schistosomes were able to mate and produce viable eggs. This highlights an additional biological challenge in achieving elimination of schistosomiasis.


Assuntos
Schistosoma japonicum , Esquistossomose Japônica , Esquistossomose , Animais , Feminino , Fertilidade , Masculino , Camundongos , Reprodução
11.
Nanoscale ; 13(11): 5594-5619, 2021 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-33720254

RESUMO

The successful fabrication of WS2/MoS2 heterostructures provides more possibilities for optoelectronic and thermoelectric applications than graphene because of their direct bandgap characteristics; therefore, scientific investigations on WS2/MoS2 heterostructures are more significant and thriving. In this paper, we review the latest research progress in WS2/MoS2 heterostructures, and look forward to their properties and applications. Firstly, we analyze the crystal structure and electronic structure of WS2, MoS2, and their heterostructures. Secondly, we comprehensively present the widely used methods for preparing heterostructures. Finally, based on the unique physical characteristics of WS2/MoS2 heterostructures, we focus on their properties and applications in mechanics, electronics, optoelectronics, and thermoelectronics.

12.
Chem Rec ; 21(4): 797-819, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33539663

RESUMO

In this review, we focus on the summary of catalytic reaction driven by surface plasmons and plexciton, where the plexciton is the interaction between plasmon and exciton. We first review the reduction and oxidation reactions driven by plasmons, and analyze the role of plasmons in the two reactions. We then summarize the recent research on the surface catalytic reactions driven by plasmon-exciton coupling and discuss the promotion effect of coupling interaction in oxidation reaction and reduction reaction. The coupling effect of plasmons and excitons can successfully improve the efficiency of catalytic reactions. Finally, this paper demonstrates the research progress in the electrooptical synergic plasmon-exciton co-driven surface catalytic reactions.

13.
Nanoscale ; 13(2): 581-601, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33410859

RESUMO

In this review, the development context and scientific research results of chiral surface plasmons (SPs) in recent years are classified and described in detail. First, the principle of chiral SPs is introduced through classical and quantum theory. Following this, the classification and properties of different chiral structures, as well as the superchiral near-field, are introduced in detail. Second, we describe the excitation and propagation properties of chiral SPs, which lays a good foundation for the application of chiral SPs and their chiral spectra in various fields. After that, we have summarized the recent research results of chiral SPs and their applications in the areas of biology, two-dimensional materials, topological materials, analytical chemistry, chiral sensing, chiral optical force, and chiral light detection. Chiral SPs are a new type of optical phenomenon that have useful application potential in many fields and are worth exploring.

14.
Chem Rec ; 20(12): 1474-1504, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32970383

RESUMO

Gold nanoparticles have excellent optical and plasmon properties and have enormous research potential when they combine with different ligands. Functionalized gold nanoparticles are widely used in drug delivery, biological detection, sensors, and even clinical treatment. At present, with the rapid development of functionalized gold nanoparticles, we think it is necessary to sort out the recent research results. In this paper, the synthesis, characteristics, and biological applications of the three aspects are introduced. Firstly, the synthetic methods of functionalized gold nanoparticles are reviewed, and the improvement of the commonly used synthetic methods is summarized. Then, the catalytic properties, oxidation resistance, and chirality optical properties are summarized in detail. Finally, we summarize the research progress in the field of biology in recent years.


Assuntos
Ouro/química , Nanopartículas/química , Microscopia Eletrônica de Transmissão , Espectrofotometria Ultravioleta , Ressonância de Plasmônio de Superfície
15.
Chem Rec ; 20(9): 1043-1073, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32779364

RESUMO

Gold nanorods are anisotropic and exhibit different optical characteristics in both transverse and longitudinal directions, so the plasmon resonance in the near-infrared region will reflect two absorption peaks. Because of strong enhancements of electromagnetic fields of gold nanorods, gold nanorods are widely used in medical treatment, biological detection, sensors, solar cells and other fields. Since rapid developments of gold nanorods, it is necessary to sort out the recent achievements. In this review, we select three classifications of single nanorods/nanowires, dimers and assembled nanorods to introduce their syntheses methods, optical properties and applications respectively. We firstly overview the history of nanorods/nanowires syntheses and summarize the improvement of the commonly utilized seed-mediated growth synthesis method; and then, physically, nano-plasmonic and optical properties of single and assembled nanorod/nanowires are concluded in detail. Lastly, we mainly summarize the recent advances in applications and provide perspective in different fields.

16.
Spectrochim Acta A Mol Biomol Spectrosc ; 242: 118780, 2020 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-32801023

RESUMO

In this work, we use the visualization method to study their intramolecular electric-magnetic interactions and reveal the physical mechanism of their electronic transition to explain the cause of the opposite ECD spectrum orientations. Azaphilone A and B are two chiral molecules, due to their differing chirality, the electronic circular dichroism (ECD) spectra of bromophilone A and B are very different at 431 nm. Based on the two-step transition process, the charge-transfer characteristics of the corresponding two-photon excited states of the two chiral molecules are analysed in detail by calculating the photoinduced charge transfer and electron-hole coherence in the two-photon absorption (TPA) process.

17.
Chem Rec ; 20(9): 894-911, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32343030

RESUMO

We introduce the principle and applications of one-photon absorption (OPA) and two-photon absorption (TPA) controlled by external electric fields. The physical mechanism of OPA and TPA are firstly introduced, which can visually promote thoroughly understanding of principle and physical analysis. Secondly, the applications of different molecules in OPA and TPA with and without external electric field are introduced in detail. The effect of the external electric field on the charge transfer during the absorption process is also exemplified. Furthermore, the external electric field on the molecular orbital wave function is visualized through the charge transfer process in the excited state transitions. The purpose of this review is to deepen the understanding of the types of charge transfer under linear and non-linear absorption in different systems.

18.
Spectrochim Acta A Mol Biomol Spectrosc ; 229: 117858, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31813728

RESUMO

By using the ab initio density-functional theory method, we investigated the charge redistribution of monolayer graphene with ZigZag and/or ArmChair edges upon infrared excitation. The photoinduced charge redistribution is strongly dependent on edge types. The priority of electrons transfer has been revealed by charge density difference. To further investigate the influence of edge types on optical properties, the dielectric constants and absorption coefficient of graphene with various edge types have been calculated. The edge types have a non-negligible influence on optical properties of graphene, and the Zigzag edge graphene owns stronger optical absorption in infrared region. Our results are potentially beneficial for designing graphene nanodevices in the infrared region.

19.
Opt Express ; 27(16): A995-A1003, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31510488

RESUMO

The excited-state carrier dynamics of lead halide perovskites play a critical role in their photoelectric properties, and are greatly affected by lattice structural changes. In this work, the carrier dynamics of all-inorganic CsPbBr3 peroveskite, as a function of pressure, are investigated using in situ high-pressure femtosecond transient absorption spectroscopic experiments. Compression is found to drive crystal structural evolution, thereby markedly changing the behavior of charge carriers in CsPbBr3. Before the phase transition, simultaneous prolonging of the carrier relaxation and Auger recombination is achieved alongside a narrowing in the bandgap. The results favor improved efficiency and photovoltaic performance.

20.
J Phys Chem A ; 123(37): 8071-8081, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31461280

RESUMO

The chiral source and its mechanism in the molecular system are of great significance in many fields. In this work, we proposed visualized methods to investigate the physical mechanism of a chiral molecule, where the electric and magnetic interactions are visualized with the transitional electric dipole moment, the transitional magnetic dipole moment, and the transitional electric quadrupole moment, and their tensor product. This will also serve as an effective means of visualizing the interaction of light with matter. The relationship between the molecular Raman optical activity (ROA) response and molecular structure was analyzed in an intuitive way. The relationship between chromophore chirality and molecular vibration mode are revealed via interaction between the transition electric dipole moment and the transition magnetic dipole moment. The molecular chirality is derived from the anisotropy of the molecular transition electric dipole moment and the transition magnetic dipole moment. The anisotropic dipole moment localized molecular chromophore is the source of the vibration mode in which the ROA responds to the reverse.

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