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Chemiluminescence is a powerful analytical technique with many advantages, while aptamers are well-known as good molecular recognition units. However, many aptamer-based chemiluminescence assays employed interface sensing, which often needed several immobilization, separation, and washing steps. To minimize the risks of contamination and false-positive, we for the first time proposed a photocatalytic aptamer chemiluminescent system for a homogeneous, label-free, generic assay of small molecules. After binding to a DNA aptamer, thioflavin T has a unique photocatalytic oxidase activity to activate the system's luminol chemiluminescence. Then, the specific binding between the aptamer and target molecules will compete with the above process. Therefore, we can realize the efficient assay of different analytes including estradiol and adenosine. Such a homogeneous chemiluminescent system allowed a direct assay of small molecules with limits of detection in a nM level. Several control tests were carried out to avoid possible false-positive results, which were originated from the interactions between analytes and sensing interfaces previously. This homogeneous chemiluminescent system provides a useful strategy to reliably assay various analytes in the pharmacy or biology field.
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Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Técnicas Biossensoriais/métodos , Aptâmeros de Nucleotídeos/química , Medições Luminescentes/métodos , Luminol/química , AdenosinaRESUMO
The accurate discrimination of single-nucleotide variants is of great interest for disease diagnosis and clinical treatments. In this work, a unique DNA probe with "Hill-type" cooperativity was first developed based on toehold-mediated strand displacement processes. Under simulation, this probe owns great thermodynamics advantage for specificity due to two mismatch bubbles formed in the presence of single-nucleotide variants. Besides, the strategies of ΔG' = 0 and more competitive strands are also beneficial to discriminate single-nucleotide variants. The feasibility of this probe was successfully demonstrated in consistent with simulation results. Due to "Hill-type" cooperativity, the probe allows a steeper dynamic range compared with previous probes. With simulation-guided rational design, the resulting probe can accurately discriminate single-nucleotide variants including nucleotide insertions, mutation, and deletions, which are arbitrarily distributed in target sequence. Two specificity parameters were calculated to quantitatively evaluate its good discrimination ability. Hence, "Hill-type" cooperativity can serve as a novel strategy in DNA probe's design for accurate discrimination of single-nucleotide variants.
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DNA , Nucleotídeos , Hibridização de Ácido Nucleico , Sondas de DNA/genética , DNA/genética , MutaçãoRESUMO
Homogeneous assays often obviate any separation and washing steps, thus minimizing the risks of contamination and false positive. DNA toehold exchange is a homogeneous, reversible process whose thermodynamic properties can be finely tuned for various assay applications. However, the developed probes often rely on direct interactions of analytes with DNA strands involved in toehold exchange, limiting the versatility of probe design. Here, the coaxial adjacent stacking between one auxiliary strand and another invading strand offers a favorable ΔG to shift one DNA balance, while the auxiliary strand is independent of the DNA balance itself. Therefore, such a DNA balance allowed fine tuning of the equilibrium via adjustment of the auxiliary strand alone. The energy contribution of base stacking can be quantified in a homogeneous solution based on the difference in the equilibrium constant. Besides, the proof of concept for DNA balance allows effective assay of a small molecule or ribonuclease in a homogeneous solution. This novel DNA balance via adjacent base stacking provides an interesting alternative to homogeneously assay various analytes.
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PURPOSE: To describe the prevalence and analyse the associated factors of possible sarcopenia and sarcopenia among community-dwelling old adults in China, in order to provide effective strategies for early prevention and treatment of sarcopenia. METHODS: This cross-sectional study evaluated community-dwelling old adults aged over 60 years. The basic information, morphological indices, body composition, physical activities were collected and assessed. Possible sarcopenia and sarcopenia were diagnosed by the criteria of Asian Working Group for Sarcopenia (AWGS) in 2019. A multivariate logistic regression model with stepwise method was employed to identify factors associated with possible sarcopenia and sarcopenia. RESULTS: In total 729 old adults from Tianjin were included in this study. Eighty-one participants were diagnosed with possible sarcopenia (prevalence of 11.11%). Seventy-five participants were diagnosed with sarcopenia (prevalence of 10.29%). Age (odds ratio (OR):1.047, 95% confidence interval (CI): 1.055-1.090) and lower physical activities (low level OR:4.171, 95% CI:1.790-9.720; medium level OR:2.634, 95% CI:1.352-5.132) were significantly associated with possible sarcopenia. Age (OR:1.187, 95% CI:1.124-1.253), higher body fat percentage (OR:1.225, 95% CI:1.140-1.317), lower BMI (OR:0.424, 95% CI:0.346-0.519), lower mini-mental state examination (MMSE) scores (OR:0.865,95% CI:0.781-0.958) and low physical activities (OR:4.638, 95% CI:1.683-12.782) were significantly associated with sarcopenia. CONCLUSION: Possible sarcopenia and sarcopenia are prevalent among community-dwelling old adults in China. Ageing and lower physical activities were both associated with possible sarcopenia and sarcopenia. Old adults with sarcopenia more likely have higher body fat percentage, lower BMI and lower cognitive function compared with those without this condition.
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Sarcopenia , China/epidemiologia , Estudos Transversais , Humanos , Vida Independente , Prevalência , Sarcopenia/diagnóstico , Sarcopenia/epidemiologiaRESUMO
BACKGROUND: Sarcopenia refers to the progressive loss of skeletal muscle mass and muscle function, which seriously threatens the quality of life of the older adults. Therefore, early diagnosis is urgently needed. This study aimed to explore the changes of serum protein profiles in sarcopenia patients through a cross-sectional study, and to provide the reference for clinical diagnosis. METHODS: This study was a cross-sectional study carried out in the Tianjin institute of physical education teaching experiment training center from December 2019 to December 2020. Ten older adults were recruited, including 5 sarcopenia and 5 healthy older adults. After a detailed diagnostic evaluation, blood samples were collected to prepare serum for proteomic analysis using the HPLC System Easy nLC method. The differentially expressed proteins (DEPs) were screened by the limma package of R software (version 4.1.0). RESULTS: A total of 114 DEPs were identified between the patients and healthy older adults, including 48 up-regulated proteins and 66 down-regulated proteins. The functional enrichment analysis showed that the 114 DEPs were significantly enriched in 153 GO terms, which mainly involved in low-density lipoprotein particle remodeling, and negative regulation of immune response,etc. The PPI network further suggested that the cholesteryl ester transfer protein and Apolipoprotein A2 could serve as biomarkers to facilitate diagnosis of sarcopenia. CONCLUSIONS: This study provided a serum proteomic profile of sarcopenia patients, and identified two proteins with diagnostic value, which might help to improve the diagnostic accuracy of sarcopenia.
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Sarcopenia , Idoso , Apolipoproteína A-II/metabolismo , Biomarcadores/metabolismo , Proteínas de Transferência de Ésteres de Colesterol/metabolismo , Estudos Transversais , Força da Mão/fisiologia , Humanos , Lipoproteínas LDL/metabolismo , Força Muscular/fisiologia , Músculo Esquelético , Proteômica , Qualidade de VidaRESUMO
2D covalent organic frameworks (COFs) are receiving ongoing attention in semiconductor photocatalysis. Herein, we present a photocatalytic selective chemical transformation by combining sp2 carbon-conjugated porphyrin-based covalent organic framework (Por-sp2 c-COF) photocatalysis with TEMPO catalysis illuminated by 623â nm red light-emitting diodes (LEDs). Highly selective conversion of amines into imines was swiftly afforded in minutes. Specifically, the π-conjugation of porphyrin linker leads to extensive absorption of red light; the sp2 -C=C- double bonds linkage ensures the stability of Por-sp2 c-COF under high concentrations of amine. Most importantly, we found that crystalline framework of Por-sp2 c-COF is pivotal for cooperative photocatalysis with (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO). This work foreshadows that the outstanding hallmarks of COFs, particularly crystallinity, could be exploited to address energy and environmental challenges by cooperative photocatalysis.
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Two-dimensional (2D) piezoelectric semiconductor materials are garnering significant attention in applications such as intelligent sensing and energy harvesting due to their exceptional physical and chemical properties. Among these, molybdenum disulfide (MoS2), a 2D wide-bandgap semiconductor, exhibits piezoelectricity in odd-layered structures due to the absence of an inversion symmetry center. In this study, we present a straightforward chemical vapor deposition (CVD) technique to synthesize monolayer MoS2 on a Si/SiO2 substrate, achieving a lateral size of approximately 50 µm. Second-harmonic generation (SHG) characterization confirms the non-centrosymmetric crystal structure of the wide-bandgap MoS2, indicative of its piezoelectric properties. We successfully transferred the triangular MoS2 to a polyethylene terephthalate (PET) flexible substrate using a wet-transfer method and developed a wide-bandgap MoS2-based micro-displacement sensor employing maskless lithography and hot evaporation techniques. Our testing revealed a piezoelectric response current of 5.12 nA in the sensor under a strain of 0.003% along the armchair direction of the monolayer MoS2. Furthermore, the sensor exhibited a near-linear relationship between the piezoelectric response current and the strain within a displacement range of 40-100 µm, with a calculated response sensitivity of 1.154 µA/%. This research introduces a novel micro-displacement sensor, offering potential for advanced surface texture sensing in various applications.
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In recent years, wearable e-skin has emerged as a prominent technology with a wide range of applications in healthcare, health surveillance, human-machine interface, and virtual reality. Inspired by the properties of human skin, arrayed wearable e-skin is a novel technology that offers multifunctional sensing capabilities. It can detect and quantify various stimuli, mimicking the human somatosensory system, and record a wide range of physical and physiological parameters in real time. By combining flexible electronic device units with a data acquisition system, specific functional sensors can be distributed in targeted areas to achieve high sensitivity, resolution, adjustable sensing range, and large-area expandability. This review provides a comprehensive overview of recent advances in wearable e-skin technology, including its development status, types of applications, power supply methods, and prospects for future development. The emphasis of current research is on enhancing the sensitivity and stability of sensors, improving the comfort and reliability of wearable devices, and developing intelligent data processing and application algorithms. This review aims to serve as a scientific reference for the intelligent development of wearable e-skin technology.
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Fontes de Energia Elétrica , Dispositivos Eletrônicos Vestíveis , Humanos , PeleRESUMO
Perfluorinated compounds (PFCs) are useful man-made chemicals and serve as new emerging organic pollutants due to their environmental and health concerns. Chromatography-mass detection methods often need complex procedure and are also too expensive, so there is a critical demand to develop rapid, inexpensive, easy-to-operate and sensitive methods for PFCs detection. In this work, double fluorescent biosensors ('DT sensor' and 'FT sensor') have been designed to quantitatively detect long-chain perfluorinated compounds (PFCs), due to their strong hydrophobic interaction with DNA probe or lysozyme fiber. The ratio and rapid fluorescence responses offered more obvious signal changes, and high sensitivity with a limit of detection (LOD) of 0.16 µM (98.2 ppb) for perfluorododecanoic acid (PFDoA). For three PFCs with longer perfluoroalkyl chain (CF2), increased detection sensitivity was achieved due to a stronger hydrophobicity. The fluorescent biosensors showed a good selectivity for long-chain PFCs and served as cross-reactive sensors to differentiate three different long-chain PFCs. The biosensors also had robust signal response in tap water or serum samples, and the LOD can be further lowered to pM (ppt) level after sample preconcentration.
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Técnicas Biossensoriais , Monitoramento Ambiental , Poluentes Ambientais , Fluorocarbonos , Humanos , Sondas de DNA , Poluentes Ambientais/análise , Fluorocarbonos/análise , Limite de Detecção , Muramidase/química , Poluentes Químicos da Água/análise , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Monitoramento Ambiental/instrumentaçãoRESUMO
Ti-incorporated mesoporous materials have widespread applications in photocatalysis. Their adjustable pores could accommodate dyes like alizarin red S (ARS) to circumvent the lack of visible light response. Herein, Ti-MCM-41 was obtained to anchor visible light-capturing ARS, forming ARS-Ti-MCM-41. The ARS-Ti-MCM-41 was screened for the selective photocatalytic oxidation of organic sulfides. To improve the stability of the anchored ARS, electron transfer was orchestrated by a mediator trimethylamine (TMA, 2 mol%) illuminated by blue LEDs. Phenyl methyl sulfide could be almost entirely converted into phenyl methyl sulfoxide with 99% of selectivity within 18 min. In addition, Ti-MCM-41 was beneficial for the anchored ARS, which in turn guaranteed good recycling performance of ARS-Ti-MCM-41. The solvent trifluoroethanol enabled the stability of TMA and facilitated the highly selective formation of the target sulfoxides. This work sheds light on the vast possibility for visible light photocatalysis of dye-mesoporous materials.
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Corantes , Sulfetos , Catálise , Titânio , LuzRESUMO
Pesticide carbaryl can cause serious environmental pollution and its sensitive detection is of increasing interest. Gold nanoparticles (AuNPs) are classically colorimetric probes for detection of many analytes, but the instability in complex media limits their application. Here, Au@Ova NPs have been developed as a stable, effective, sensitive, and selective sensing system for colorimetric detection of carbaryl. Au@Ova NPs present unique and proper colloidal stability in various medias containing salt, small molecules, organic solvent (DMSO), and seawater, which are distinct from previous ones including citrate (or rhodamine B) capped AuNPs. Compared with Au@BSA NPs, Au@Ova NPs showed efficient responses to carbaryl by inhibiting acetylcholinesterase, with a linear concentration range between 0 and 25 µg/L and a detection limit of 0.25 µg/L. In addition, this nanoprobe also has good selectivity and can be applied in different real samples analysis, including fruit juice (tomato and apple) and real water samples (artificial urine and seawater).
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Ouro , Nanopartículas Metálicas , Colorimetria , Carbaril/análise , Ovalbumina , AcetilcolinesteraseRESUMO
Inadequate cytoreductive surgery (CRS) has been identified as a prognostic factor for poor patient outcomes in cases of peritoneal metastasis. While imaging probes are used to identify peritoneal metastasis to facilitate CRS, many of these probes exhibit high background signals, resulting in a significant delay in achieving a satisfactory tumor-to-normal ratio (TNR) due to prolonged clearance time. In this study, we designed a novel fluorescent probe named Tras-AA-Cy NH2, which enables the relatively rapid imaging of subcutaneous tumors and peritoneal tumors while maintaining a high TNR. Mechanistically, Tras-AA-Cy NH2 exhibits selective targeting towards the Human epidermal growth factor receptor 2 on the surface of cancer cells. Following internalization, it undergoes enzymatic cleavage catalyzed by the overexpressed cathepsin, leading to the subsequent release of near-infrared fluorophores. Consequently, Tras-AA-Cy NH2 achieved a TNR of 7.8 at 6 h and 21.4 at 24 h in subcutaneous tumor mice. Even after 522 h of in vivo circulation, the TNR remained above 5, indicating an ultralong imaging time window. It is noteworthy that Tras-AA-Cy NH2 has demonstrated successful utilization for peritoneal tumor-specific imaging and further affirmed its tumor tissue-specific recognition capability using human resected tissues. In summary, these findings underscore the rational design of Tras-AA-Cy NH2 for visualizing peritoneal tumors.
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Neoplasias Peritoneais , Humanos , Animais , Camundongos , Neoplasias Peritoneais/diagnóstico por imagem , Neoplasias Peritoneais/secundário , Catepsinas/metabolismo , Fluorescência , Corantes Fluorescentes/metabolismo , Imagem Óptica/métodosRESUMO
Numerous applications in visible light photocatalysis have been found over conjugated microporous polymers (CMPs) whose function could be rationally designed at the molecular level. In this context, the oxidation of thiols into disulfides entails proton and electron transfer and thus requires both Brønsted base and photocatalysis, which could be both combined into CMPs. With carbazole as a Brønsted base and an electron donor, CMPs were constructed to implement the synergistic deprotonation and oxidation of thiols into disulfides in ethanol (C2H5OH). Gratifyingly, the bifunctional CMPs could activate molecular oxygen (O2) to superoxide anion (O2â¢-) and promote the blue light-induced selective oxidation of thiols into symmetrical disulfides with high efficiency in C2H5OH. More remarkably, the highly selective formation of unsymmetrical disulfides could also be achieved without adding a Brønsted base. This work highlights the feasibility of combining cooperative photocatalysis into CMPs for versatile chemical transformations.
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Dissulfetos , Compostos de Sulfidrila , Dissulfetos/química , Luz , Oxigênio , Polímeros/químicaRESUMO
One sustainable concept emerges to implement the selective oxidation of sulfides with dioxygen (O2) at ambient conditions and has received increasing attention. As such, three donor-acceptor (D-A) type conjugated microporous polymers (CMPs) were connected via robust CC bonds prepared from FeCl3-promoted polymerization of monomers of 3,6-di(9H-carbazol-9-yl)-9H-fluorene with the 9H position of the fluorene moiety occupied by 1,1'-biphenyl-, difluoro-, or keto- group, furnishing 9,9'-(9,9'-spirobi[fluorene]-2,7-diyl)-bis-9H-carbazole-CMP (SFC-CMP), 9,9'-(9,9-difluoro-9H-fluorene-2,7-diyl)bis(9H-carbazole)-CMP (FFC-CMP), and 2,7-di(carbazol-9-yl)-fluoren-9-one-CMP (OFC-CMP), respectively. These three carbazole-fluorene CMPs could implement blue light-driven highly selective oxidation of sulfides into sulfoxides with O2 in methanol (CH3OH). Intriguingly, the SFC-CMP imparted the best photocatalytic activity for selective oxidation of sulfides in a broad scope. Besides, the SFC-CMP photocatalyst could be fully recovered even outperforming the fresh one. This work highlights that the properties of CMPs could be regulated by the D-A units like carbazole-fluorene to execute selective chemical transformations ambiently.
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Polímeros , Sulfetos , Carbazóis , Fluorenos , OxigênioRESUMO
Carbaryl is a widely-used carbamate pesticide and the detection of its residues in environmental, food and clinical samples is of great importance. In this sturdy, we developed a green photocatalytic-biosensor based on double strand DNA-SYBR green I complex for sensitively colorimetric detection of carbaryl. This green photocatalytic-biosensor can oxidize 3,3',5,5'-tetramethylbenzidine (TMB) into blue ox-TMB. Meanwhile thiocholine is catalytically produced by acetylcholinesterase (AChE) to directly reduce blue ox-TMB into colorless TMB. But the activity of AChE will be suppressed by carbaryl, thus generating less thiocholine and resulting in more ox-TMB for colorimetric analysis. After the careful optimization of sensing conditions (2 µM for DNA concentration, 50 × concentration for SYBR Green I, 10 min for illumination time), the lowest detectable concentration for carbaryl is 0.008 ng/mL with a linear response in the range of 0.01-0.25 ng/mL. In addition, this photocatalytic-biosensor has good selectivity over non-target chemicals (acetamiprid, atrazine, carbendazim, melamine, bisphenol A, estradiol). It also allows detection of pesticides in real samples verified by a standard HPLC method.
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Técnicas Biossensoriais , Praguicidas , Acetilcolinesterase/química , Carbaril , Inibidores da Colinesterase/análise , Colorimetria/métodos , Praguicidas/análise , TiocolinaRESUMO
The special hollow core-shell structure and excellent dielectric-magnetic loss synergy of composite materials are two crucial factors that have an important influence on the microwave absorption properties. In this study, hollow ZnFe2O4 nanospheres were successfully synthesized by a solvothermal precipitation method firstly; based on this, a C shell precursor phenolic resin was coated on the ZnFe2O4 hollow nanospheres' surface by an in situ oxidative polymerization method, and then ZnFe2O4@C was obtained by high-temperature calcination. Samples were characterized by SEM, TEM, XRD, XPS, BET, VSM, VNA. The results show that the maximum reflection loss (RLmax) reaches -50.97 dB at 8.0 GHz, and the effective bandwidth (EAB) of hollow core-shell structure ZnFe2O4@C is 3.2 GHz (6.16-9.36 GHz) with a coating thickness of 3.5 mm. This work provides a useful method for the design of lightweight and high-efficiency microwave absorbers.
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Numerous studies have demonstrated that type 2 diabetes (T2D) is closely linked to the occurrence of Alzheimer's disease (AD). Nevertheless, the underlying mechanisms for this association are still unknown. Insulin resistance (IR) hallmarked by hyperinsulinemia, as the earliest and longest-lasting pathological change in T2D, might play an important role in AD. Since hyperinsulinemia has an independent contribution to related disease progressions by promoting inflammation in the peripheral system, we hypothesized that hyperinsulinemia might have an effect on microglia which plays a crucial role in neuroinflammation of AD. In the present study, we fed 4-week-old male C57BL/6 mice with a high-fat diet (HFD) for 12 weeks to establish IR model, and the mice treated with standard diet (SD) were used as control. HFD led to obesity in mice with obvious glucose and lipid metabolism disorder, the higher insulin levels in both plasma and cerebrospinal fluid, and aberrant insulin signaling pathway in the whole brain. Meanwhile, IR mice appeared impairments of spatial learning and memory accompanied by neuroinflammation which was characterized by activated microglia and upregulated expression of pro-inflammatory factors in different brain regions. To clarify whether insulin contributes to microglial activation, we treated primary cultured microglia and BV2 cell lines with insulin in vitro to mimic hyperinsulinemia. We found that hyperinsulinemia not only increased microglial proliferation and promoted M1 polarization by enhancing the production of pro-inflammatory factors, but also impaired membrane translocation of glucose transporter 4 (GLUT4) serving as the insulin-responding glucose transporter in the processes of glucose up-taking, reduced ATP production and increased mitochondrial fission. Our study provides new perspectives and evidence for the mechanism underlying the association between T2D and AD.
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Feature variable selection and modeling are two of the most principal research contents in spectral analysis. In the present paper, beginning from the introduction of feature spectrum selection based on Tikhonov regularization and discussion on it's application in multi-component mixed alkane gas analysis, 7 sets of feature spectra were abstracted from the absorption spectra of 7 kinds of alkane gas, including methane, ethane, propane, iso-butane, n-butane, iso-pentane and n-pentane. In order to overcome the problem of over-training of neural network, a method called optimal parameter selection of neural netework (NN) was presented to build analysis model of analyte. Optimal parameters were selected from many trained networks with same architecture based on error process. And analysis models of spectral analysis for 7 kinds of alkane gas were built. Finally, the testing analysis results done with standard gases are given. The results show that the method presented in this paper can be used to reduce the cross--sensitivity between any two kinds of gas. The cross-sensitivity is less than 0.5%. The resolving power is as high as 20 X 10(-6).
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A novel thickness measurement method for surface insulation coating of silicon steel based on NIR spectrometry is explored. The NIR spectra of insulation coating of silicon steel were collected by acousto-optic tunable filter (AOTF) NIR spectrometer. To make full use of the effective information of NIR spectral data, discrete binary particle swarm optimization (DBPSO) algorithm was used to select the optimal wavelength variates. The new spectral data, composed of absorbance at selected wavelengths, were used to create the thickness quantitative analysis model by kernel partial least squares (KPLS) algorithm coupled with Boosting. The results of contrast experiments showed that the Boosting-KPLS model could efficiently improve the analysis accuracy and speed. It indicates that Boosting-KPLS is a more accurate and robust analysis method than KPLS for NIR spectral analysis. The maximal and minimal absolute error of 30 testing samples is respectively--0.02 microm and 0.19 microm, and the maximal relative error is 14.23%. These analysis results completely meet the practical measurement need.
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Recently, conjugated microporous polymers (CMPs) comprised of thiazolo[5,4-d]thiazole (TzTz) linkages have received much attention due to their excellent photoelectric properties. Herein, the polycondensation of dithiooxamide and benzyl aldehydes of C2, C3, and D2h symmetry afforded three TzTz-linked CMPs, namely TzTz-CMP-1, TzTz-CMP-2, and TzTz-CMP-3. Importantly, the porous and flexible characteristics of TzTz-linked CMPs enable the smooth selective aerobic oxidation of amines in ethanol (C2H5OH), a clean but redox-active solvent. All three TzTz-linked CMPs significantly surpass the benchmark mesoporous graphite carbonnitride (mpg-C3N4) photocatalyst. Intriguingly, TzTz-CMP-2 displays the best photocatalytic activity for the blue-light-mediated selective transformation of primary and secondary amines into imines. The conversions of amines were up to 90% with excellent selectivities for imines. This work highlights that CMPs with TzTz linkages may offer efficient photocatalytic selective transformations under genuinely ambient conditions.