RESUMO
Perfect absorption with adjustable Q factor and wavelength is essential in both theory and application. To address this issue, a structure composed of an epsilon-near-zero (ENZ)- SiO2 grating and a multilayer dielectric structure was designed. In the structure, the intrinsic loss is related to the ENZ thickness, while the external leakage depends on the grating parameters. By adjusting the ENZ film thickness, the intrinsic loss rate was tuned to match the external leakage rate corresponding to different grating parameters, realizing the critical couplings with different Q factors and wavelengths. Under critical coupling, the absorption rate reached a maximum of 99.999%, demonstrating ultra-perfect absorption. The Q factor was adjusted from 4350 to 35800, and the absorption wavelength was modified from 1050 to 1282 nm. The design work may provide new ideas for developing wavelength- and Q-selective absorbers, optical modulators, dielectric sensors, and photodetectors.
RESUMO
The modulation of microstructures in conjugated polymers represents a viable strategy for enhancing photocatalytic efficiency, albeit hampered by complex processing techniques. Here, we present an uncomplicated, template-free method to synthesize polymeric photocatalysts, namely BCN(x)@PPy, featuring a hollow nanotube-nanocluster core-shell superstructure. This configuration is realized through intramolecular covalent crosslinking and synergistic intermolecular donor-acceptor (D-A) interactions between phenylene pyrene (PPy, D) nanotubes and poly([1,1'-biphenyl]-3-carbonitrile) (PBCN, A) nanoclusters. Interestingly, the optimized BCN2@PPy composite demonstrates remarkably enhanced performance for photocatalytic hydrogen evolution, with an efficiency of 14.7-fold higher than that of unmodified PPy nanotubes. Experimental and density functional theory calculations revealed that BCN(x)@PPy composites are conducive to shortening photogenerated exciton migration, facilitating charge separation and transfer, reducing nanoclusters aggregation or re-stacking, and providing sufficient catalytically active sites, all contributing to the heightened efficiency in photocatalysis. These insights underscore the potential for precise molecular adjustments in conjugated polymers, advancing artificial photosynthesis.
RESUMO
In this study, a novel green fluorescent probe material, nitrogen-doped carbon quantum dots (N-CQDs), was prepared by a one-step hydrothermal synthesis method using walnut green skin as a carbon source and acetamide-glycolic acid deep eutectic solvent (AGADES) as a modifier. By covalent coupling, the amide chromophore in AGADES is designed to cover the surface of walnut green skin carbon quantum dots (W-CQDs), forming a fluorescence energy resonance effect and improving the fluorescence performance of the carbon quantum dots. The prepared N-CQDs have a uniform particle size distribution, and the fluorescence quantum efficiency has increased from 12.5% to 32.5%. Within the concentration range of 0.01~1000 µmol/L of Pb2+, the linear detection limit is 1.55 nmol/L, which can meet the trace detection of Pb2+ in the water environment, and the recycling rate reaches 97%. This method has been successfully applied to the fluorescence detection and reuse of Pb2+ in actual water bodies, providing new ideas and methods for the detection of heavy metal ions in environmental water.
RESUMO
Since carbon dots (CDs) with good water solubility are preferred by researchers and biological applications, a hydrothermal method was used to synthesize green fluorescent CDs with an excitation-independent peak at 526â nm using deionized water as the solvent and neutral red as the carbon source. To achieve spectral modulation, the pH of the solvent was adjusted with KOH to obtain orange CDs (O-CDs) in an alkaline environment, with the emission peak red-shifted to 630â nm. The water-soluble CDs were prepared for multidimension sensing as Fe3+ sensing (on/off). Carbon dots dispersed into a silica gel matrix can be used for fingerprint detection of various materials.
RESUMO
Developing visible to near-infrared light-absorbing conjugated polymer photocatalysts is crucial for enhancing solar energy utilization efficiency, as most conjugated organic polymers only absorb light in the visible range. In this work, we firstly developed a novel thiophene S,S-dioxide (TDO) monomer with the stronger electron-withdrawing character, and then prepared a series of donor-acceptor1-donor-acceptor2-type (D-A1-D-A2-type) conjugated terpolymers (THTDB-1-THTDB-5) by statistically adjusting the molar ratio of two sulfone-based acceptor monomers, dibenzothiophene-S,S-dioxide (BTDO, A1) and TDO (A2). These terpolymers demonstrate a gradually expanding absorption range from visible light to the second near-infrared (Vis-to-NIR-II) region with the gradual increase of the TDO contents in the polymer skeleton, showcasing excellent absorption properties and efficient light-capturing capabilities. The optimized D-A1-D-A2 polymer photocatalyst THTDB-4 exhibits a high hydrogen evolution rate of 21.27 mmol g-1 h-1 under visible light without any co-catalyst. The dual-sulfone-acceptor engineering offers a viable approach for developing efficient the longer Vis-to-NIR-II light-harvesting polymer photocatalysts.
RESUMO
At present, the fast distinction of different metal ions in pure water media is not only a great challenge, but also drives the protection of water quality in environmental water bodies. In this paper, a novel ionic liquid fluorescent probe Glycolic Acid-L-Arginine (GA-L-Arg) was rationally created and designed through an in-depth study of ionic liquids. It is also used as an innovative multi-ion fluorescent probe for colorimetric detection and separate identification of Fe3+ and Co2+ in aqueous solutions of various metal ions. GA-L-Arg has excellent water solubility due to the strong hydrophilicity of Glycolic Acid and L-Arginine. The probe showed high sensitivity, extremely significant selectivity, and great pH stability for Fe3+ and Co2+ in pure water. The GA-L-Arg structure and the mechanism of Fe3+ and Co2+ detection were analyzed by infrared spectroscopic characterization and quantum chemical calculations. More importantly, the distinct colorimetric partitioning of Fe3+ and Co2+ was performed by the unique extraction of Fe3+ in the presence of the fluorescent probe and buffer solution.
Assuntos
Glicolatos , Líquidos Iônicos , Corantes Fluorescentes/química , Colorimetria/métodos , Metais/química , Íons , ArgininaRESUMO
BACKGROUND: It remains unclear whether laparoscopic multisegmental resection and anastomosis (LMRA) is safe and advantageous over traditional open multisegmental resection and anastomosis (OMRA) for treating synchronous colorectal cancer (SCRC) located in separate segments. AIM: To compare the short-term efficacy and long-term prognosis of OMRA as well as LMRA for SCRC located in separate segments. METHODS: Patients with SCRC who underwent surgery between January 2010 and December 2021 at the Cancer Hospital, Chinese Academy of Medical Sciences and the Peking University First Hospital were retrospectively recruited. In accordance with the inclusion and exclusion criteria, 109 patients who received right hemicolectomy together with anterior resection of the rectum or right hemicolectomy and sigmoid colectomy were finally included in the study. Patients were divided into the LMRA and OMRA groups (n = 68 and 41, respectively) according to the surgical method used. The groups were compared regarding the surgical procedure's short-term efficacy and its effect on long-term patient survival. RESULTS: LMRA patients showed markedly less intraoperative blood loss than OMRA patients (100 vs 200 mL, P = 0.006). Compared to OMRA patients, LMRA patients exhibited markedly shorter postoperative first exhaust time (2 vs 3 d, P = 0.001), postoperative first fluid intake time (3 vs 4 d, P = 0.012), and postoperative hospital stay (9 vs 12 d, P = 0.002). The incidence of total postoperative complications (Clavien-Dindo grade: ≥ II) was 2.9% and 17.1% (P = 0.025) in the LMRA and OMRA groups, respectively, while the incidence of anastomotic leakage was 2.9% and 7.3% (P = 0.558) in the LMRA and OMRA groups, respectively. Furthermore, the LMRA group had a higher mean number of lymph nodes dissected than the OMRA group (45.2 vs 37.3, P = 0.020). The 5-year overall survival (OS) and disease-free survival (DFS) rates in OMRA patients were 82.9% and 78.3%, respectively, while these rates in LMRA patients were 78.2% and 72.8%, respectively. Multivariate prognostic analysis revealed that N stage [OS: HR hazard ratio (HR) = 10.161, P = 0.026; DFS: HR = 13.017, P = 0.013], but not the surgical method (LMRA/OMRA) (OS: HR = 0.834, P = 0.749; DFS: HR = 0.812, P = 0.712), was the independent influencing factor in the OS and DFS of patients with SCRC. CONCLUSION: LMRA is safe and feasible for patients with SCRC located in separate segments. Compared to OMRA, the LMRA approach has more advantages related to short-term efficacy.
RESUMO
Background: Psoriasis is a complex autoimmune disease. Frequent interactions between epidermal and immune cells are likely to be responsible for the strong heterogeneity of psoriasis. Therefore, our work aims to build on current knowledge and further search for new molecular mechanisms related to psoriasis pathogenesis in order to develop new targeted drugs. Methods: Data from psoriasis samples were obtained from the Gene Expression Omnibus (GEO) database, and batch effects were corrected using the "Combat" algorithm in the "SVA" package. Functional annotation of differential genes in psoriasis was performed by Gene set enrichment analysis (GSEA). Core functional modules were identified using the Multiscale Embedded Gene Co-Expression Network Analysis (MEGENA) algorithm for selection from the differential gene interaction network. The expression and potential function of Rh Family C Glycoprotein (RHCG) was predicted in single cell data by the "Seurat" package and validated in psoriasis samples by multiplex immunofluorescence. In addition, the regulatory function of HOP Homeobox (HOPX) on RHCG in keratinocytes was confirmed using RNA interference. Using immune infiltration analysis, RHCG and DC cells were analyzed for their association. Finally, the molecular mechanisms of treatment of psoriasis using Tripterygii Radix (TR) and Cinnamomi Ramulus (CR) were explored through network pharmacology and experimental validation. Results: Immune response (represented by C1_2) and collagen matrix formation (represented by C1_3) were identified as two important pathogenic factors in psoriasis and helped to define new biological subtypes of psoriasis. One important psoriasis hub gene, RHCG, was obtained and found to be closely associated with keratinocyte differentiation as well as DC cell maturation. And RHCG was regulated by HOPX in keratinocytes. In addition, the mechanism of action of CR and TR in the treatment of psoriasis was tentatively confirmed to be related to TRPV3, NFKB2, and YAP1. Conclusions: Our study identifies a new causal disease gene (RHCG) and offers potential alternatives for the treatment of psoriasis.
Assuntos
Doenças Autoimunes , Proteínas de Transporte de Cátions , Humanos , Algoritmos , Diferenciação Celular , Bases de Dados Factuais , Glicoproteínas , Glicoproteínas de MembranaRESUMO
A new type of green carbon quantum dots (ILB-CQDs) was prepared by hydrothermal method using ionic liquid as a modifier and grape skin as carbon source, and was obtained from hydrogen-bonded lattice structure ionic liquid preparation, which makes the CQDs in a ring-like stable structure with a stability period of more than 90 day. There is also the catalytic effect of the ionic liquid on cellulose, which makes the prepared CQDs show good advantages, such as uniform particle size, high quantum yield (26.7%), and very good fluorescence performance. This is a smart material for the selective detection of Fe3+ and Pd2+. It has a detection limit of 0.001 nM for Fe3+ and 0.23 µM for Pd2+ in pure water. It has a detection limit of 3.2 nmol/L for Fe3+ and 0.36 µmol/L for Pd2+ in actual water, both of which meet the requirements of WHO drinking water standards. And there is to achieve more than 90% of water restoration effect.
Assuntos
Líquidos Iônicos , Pontos Quânticos , Água , Pontos Quânticos/química , Carbono/química , BiomassaRESUMO
Although the theory of scattered speckles was initially established via idealization of treating the incident light as monochromatic, phenomenon and regulations of wide-spectrum speckles are yet urgent to be studied, with immense growing applications of broadband source such as femtosecond laser, light-emitting-diode and sunlight illumination. Here we quantitatively analyze the morphology and statistics of speckles produced by a point-like source with wide-spectrum, using a phase plate model to describe the scattering layer. Due to differences in induced phase related to wavelength, wide-spectrum speckle patterns appear radial divergence in intensity distribution, as well as in visibility of both speckles and that of the second-order coherence. This is significantly different from the translation-invariance of monochromatic speckles. The spatially-varying morphology and statistics of the speckles contain spatial and spectral information of the incidence, thus can be used as an indicator to achieve optical metrology or sensing with a wide-spectrum source in the scattering environment.
RESUMO
Research towards practical applications of ghost imaging attracts more and more attention in recent years. Signal-to-noise ratio (SNR) of bucket results thus quality of images can be greatly affected by environmental noise, such as strong background light. We introduce temporal cross-correlation into typical ghost imaging to improve SNR of bucket value, taking temporal profile of illumination pulses as a prior information. Experimental results at sunny noontime verified our method, with the imaging quality greatly improved for the object at a distance of 1.3km. We also show the possibility of 3-dimensional imaging, experimentally.
RESUMO
A scalable enantioselective nickel-catalyzed electrochemical reductive homocoupling of aryl bromides has been developed, affording enantioenriched axially chiral biaryls in good yield under mild conditions using electricity as a reductant in an undivided cell. Common metal reductants such as Mn or Zn powder resulted in significantly lower yields in the absence of electric current under otherwise identical conditions, underscoring the enhanced reactivity provided by the combination of transition metal catalysis and electrochemistry.
RESUMO
BACKGROUND: Implantology or implant dentistry is growing fast during last four decades. Facing the growing demand of implant treatment, there are extreme challenges to clinicians and researchers. First is peri-implantitis with remarkable prevalence. Though investigators have revealed that the etiology of the peri-implant infection is similar to periodontitis, clinically there is no effective treatment. Second, implantation in patients with severe systemic conditions, i.e., severe diabetes, lupus, osteoporosis, organ transplant, and cancer with intensive radiotherapy and/or chemotherapy, is another challenge to implant treatment for lack of scientific research data. Animal models are crucial to help investigators reveal the mechanisms underlying these disorders. Murine models are used most commonly. Rats are the better subject in dental implant research, due to mice could not provide clinical compatible and macro-level measurable data for implant osseointegration and peri-implantitis in oral cavity for lacking enough cancellous bone to support an implant more than 1 mm in length. OBJECTIVE: Our aim of this research is to find a clinical comparable rat dental implant model. METHODS: Six male Sprague-Dawley rats with body weight more than 500 g were used in the experiment. Each rat received two implants. One implant was placed at maxillary diastema in each side. Seven weeks after the implantation, only one implant successfully osseointegrated without movement and inflammation. Implant success and failure rate is analyzed by using Clopper-Pearson's exact method at 95% confidence interval. RESULTS: The present data indicate that the true success rate of implantation in maxillary natural diastema in rat is less than 38.4% at a confident level of 95%. Meanwhile, Micro-CT indicates maxillary first molar position will be a promising site for implantation. CONCLUSION: Maxillary nature diastema may not be an appropriate site for implantation research for its low successful rate, but maxillary first molar position could be a candidate for implantation research. Further researches are required to illustrate the details.
RESUMO
Palladium-catalyzed transfer semihydrogenation of alkynes using H2O as the hydrogen source and Mn as the reducing reagent is developed, affording cis- and trans-alkenes selectively under mild conditions. In addition, this method provides an efficient way to access various cis-1,2-dideuterioalkenes and trans-1,2-dideuterioalkenes by using D2O instead of H2O.
RESUMO
We have developed a Ni-catalyzed enantioselective hydroarylation of styrenes with arylboronic acids using MeOH as the hydrogen source, providing an efficient method to access 1,1-diarylalkanes, which are essential structural units in many biologically active compounds. In addition, Ni-catalyzed enantioselective hydrovinylation of styrenes with vinylboronic acids is also realized with good yields and enantioselectivities. The synthetic utility was demonstrated by the efficient synthesis of ( R)-(-)-ibuprofen.
RESUMO
A triple reflection grazing incidence x-ray telescope is proposed and evaluated. This form of an optical system can detect x-ray energy that is close to the optical axis, which solves the problems encountered by traditional Wolter-type systems. In this paper, we also propose a new design method to ensure that the entire telescope structure is compact and integrated. Finally, a proof-of-concept design with an acceptable image quality is proposed.
RESUMO
Volatile organic compounds (VOCs) samples were collected and analyzed for the surface coating processes of aluminum products in Foshan. The concentration levels of VOCs from solvent-based coating (63.90-149.67 mg·m-3) are much higher than that from water-based, electrophoretic, and powder coating (2.99-21.93 mg·m-3). With respect to the VOC composition, aromatics are the main VOC group of solvent-based coating emission, ranging from 52.32%-71.55%. Typical species include toluene, ethylbenzene, xylene, and ethyl acetate. The VOCs emitted from water-based coating are mainly oxygenated VOCs, such as ethyl acetate (48.59%) and tetrahydrofuran (8.43%), while the percentage of aromatics (11.32%) is lower than that of solvent-based coating. Isopropanol is the most abundant species of electrophoretic coating emissions, accounting for up to 81.19% of the VOCs. The major VOC compounds of powder coating processes are acetone (30.25%), propane (15.48%), ethylene (12.15%), ethane (9.35%), and n-butane (5.16%). The calculation of the ozone formation potential (OFP) shows that the solvent-based coating has the highest OFP (3.89 g·g-1), followed by powder coating (2.53 g·g-1), while water-based and electrophoretic coating have lower OFPs (1.31 and 0.85 g·g-1, respectively). The most important contributor to OFP of solvent-based coating are aromatics, especially C7-C10 aromatics. The major contributors of water-based coating are ethyl acetate, m/p-xylenes, and toluene, with contributions of 23.24%, 21.76%, and 17.07%, respectively. The key reactive components of powder coating are ethylene, propene, and 1-butene; the sum of alkenes accounts for 71.11% of the OFP. With respect to the contribution of VOCs emitted from electrophoretic coating to the OFP, the percentage of isopropanol (65.08%) is significantly larger than that of other species (<6%).
RESUMO
We propose a new panossramic optical system that provides an additional field of view (FOV) channel without expanding the physical size of a conventional panoramic annular lens (PAL). The two channels are contained within one PAL, their optical paths do not interfere with each other, and the two images are realized on a single image plane. A prototype panoramic lens was developed that provides a 360° × (38-80°) front FOV channel and a 360° × (102-140°) back FOV channel.
RESUMO
An efficient Ni-catalyzed reductive carboxylation of allylic alcohols with CO2 has been successfully developed, providing linear ß,γ-unsaturated carboxylic acids as the sole regioisomer with generally high E/Z stereoselectivity. In addition, the carboxylic acids can be generated from propargylic alcohols via hydrogenation to give allylic alcohol intermediates, followed by carboxylation. A preliminary mechanistic investigation suggests that the hydrogenation step is made possible by a Ni hydride intermediate produced by a hydrogen atom transfer from water.
RESUMO
BACKGROUND: It has been suggested that dementia is caused by neuronal damage due to chronic inflammation from peripheral sources such as the oral cavity in periodontal disease. OBJECTIVE: The aim of our review was to assess the risk of dementia or cognitive impairment associated with chronic periodontitis and multiple tooth loss. MATERIALS AND METHODS: An extensive search of electronic databases of articles on the relation between periodontitis, tooth loss and dementia published on or before April 2016 was conducted. Experimental and human studies that provided a description consistent with multiple tooth loss, chronic periodontal disease and cognitive impairment obtained by validated methods were selected. The data extracted from the articles included study design, country of origin, sample size, methods used to assess periodontitis and cognition, average age at the baseline and number of years of follow-up. The Newcastle-Ottawa scale was used to assess the quality of human studies. RESULTS: The literature search yielded 756 articles which were independently screened, and 16 articles were included in the review. Four human studies reported an association of subsequent dementia with multiple tooth loss. One human study reported that chronic periodontal disease was associated with dementia. Eight experimental studies demonstrated an association between cognitive impairment and tooth loss. CONCLUSION: The literature on chronic periodontitis and multiple tooth loss as risk factors to dementia remains inconclusive. More randomised clinical trials on the association between periodontitis and dementia with uniform criteria for evaluation and diagnosis of periodontitis are warranted.