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Biomimetic light‐harvesting architecture has been proposed as an alternative for existing solar conversion systems. Chlorophyll‐sensitized TiO2 have been identified as promising catalyst for photocatalytic reduction system, but it is largely limited to complicated process for purification of chlorophyll and adding extra hole scavenger in system. In sharp contrast to conventional photosensitization methods in which the organic dyes were often adsorbed after photosensitization, herein mesoporous TiO2 incorporated with chlorophyll extract was synthesized in situ (TiO2/Chl). Interestingly, TiO2 incorporated with chlorophyll exhibited two distinct absorption bands around 407 and 668 nm which are closed to the characteristic absorption peak of chlorophyll. TiO2 incorporated with chlorophyll kept at 185°C for 1.5 hours (TiO2/Chl‐185) achieved a high photoreduction rate of 86.1% for the photocatalytic reduction of Cr(VI), which was approximately 29 and 20 times higher than that of TiO2 and TiO2 adsorbing chlorophyll (TiO2/ads Chl), respectively. The significant enhancement was due to the confinement of chlorophyll. This demonstrates that mesoporous TiO2 templated and confined with chlorophyll could offer a new approach for synergistic photoreduction of Cr(VI).

Chitosan (CS) is the only natural alkaline polysaccharide originated from deacetylation of chitin that is the main component of shell from marine organisms. It has great potential medical application due to its broad-spectrum antimicrobial activity and good water solubility originated from its protonated amino groups under acidic condition and abundant hydroxyl groups. However, unprotonated NH2 group of CS leads to its poor solubility under physiological condition and limits its diverse applications. Therefore, it is highly necessary to summarize the modification strategies of CS derivatives systematically to help researchers select the most appropriate strategies for their specific applications. Herein, we have summarized the modification strategies of CS derivatives for improving their antimicrobial activity, water solubility, biocompatibility, and mechanical property by chemical reaction and physical integration. And then we have reviewed the CS derivatives in hydrogels, nanoparticles, or coatings for medical application in wound dressing, drug delivery, medical implant. Last but not the least, we have put forward the future perspectives of deep studies about structure-activity relationship and clinical applications of CS derivatives.

Highly sensitive and rapid detection of chloramphenicol antibiotics (CAPs) in aquatic products via lateral flow immunoassay (LFA) strips remains challenging. This study developed a surface-enhanced Raman scattering (SERS)–based LFA strip for ultrasensitive analysis of CAPs by using noble metal nanoparticles (NPs). A kind of core–shell Au@Ag NPs were employed to prepare SERS tags considering the stability and repeatability. In order to obtain higher stability and repeatability, we designed antibody-modified gold@silver core–shell nanoparticles (Au@Ag NPs) as SERS nanotags for quantitative Raman detection of the target in the LFA strip. Results showed that SERS-based LFA strip allowed quantified analysis of chloramphenicol (CAP), thiamphenicol (TAP), and florfenicol (FFC) with the limits of detection of 0.36 ng/mL, 0.20 ng/mL, and 0.78 ng/mL, respectively. Furthermore, SERS-based LFA strip exhibited favorable sensitivity (IC50 values of CAP, TAP, and FFC were 12.94 ng/mL, 8.76 ng/mL, and 12.22 ng/mL, respectively). This SERS-based LFA strip was finally applied in the detection of CAP in chub and the recovery was 91.5 to 106.4%. This SERS-based LFA strip could be used as an effective tool for detecting CAPs in aquatic products.

In 2020, 5F-MDMB-PICA (5F-MDMB-2201) was one of the most common synthetic cannabinoids (SCs) identified in drugs seized by the Beijing Drug Control Agency, and it was categorized as Schedule II by the United Nations Office on Drugs and Crime in March 2020. It is difficult to detect 5F-MDMB-PICA in biological matrices due to its fast metabolic rate in vivo. In this work, 5F-MDMB-PICA metabolic profiles were investigated by liquid chromatography--quadrupole exactive high field orbitrap mass spectrometer (LC-Q Exactive HF MS), with accurate mass measurements in human urine, serum and pubic hair. To obtain intact metabolites, solid-phase extraction for urine and serum and direct ultrasonic extraction for pubic hair were applied to clean the samples without enzymatic hydrolysis. The differences in 5F-MDMB-PICA metabolism in the three different matrices were compared for the first time to determine the best detection biomarkers for monitoring 5F-MDMB-PICA misuse. Urine samples were determined to be the preferred biological material for identifying 5F-MDMB-PICA abuse. Forty-seven intact metabolites were detected in human urine, the ester hydrolyzed with glucuronidated metabolite in urine samples can be used as the primary biomarker to identify drug misuse. Fifteen metabolites were found in serum samples. Ester hydrolysis was considered to be the major metabolic pathway, and a large number of metabolites were involved with it. Zero metabolites apart from the parent drug were detected in pubic hair samples. Twenty-eight new metabolites and their metabolic pathways were characterized and tentatively identified by LC–QE-HF-MS, and a new potential biomarker (M5 ester hydrolysis + propionic acid) was also identified.

In this study, two novel mixed ACE-inhibiting peptides, namely Se-TAPep 1 and TAPep 1, were prepared and purified from selenium-enriched and common alkali-soluble proteins using a series of process, and then its physicochemical properties and oligopeptide sequence were analyzed. The results showed that Se-TAPep 1 and TAPep 1 could be successfully separated, but their ACE inhibitory activities were different (IC50 values were 13.39 mg/mL and 23.56 mg/mL, respectively), this may be related to the difference in selenium content. Further analysis of physicochemical properties showed that the protein or peptide fractions contained their characteristic absorption peaks and contained aromatic amino acids, while the apparent morphology was different, the presence of selenium could change the apparent morphology of protein or polypeptide fractions, arranging of selenium-enriched fractions more irregular. The amino acid composition analysis showed that the Pro content of the selenium-enriched fractions was higher than that of the ordinary component, whereas the oligopeptide sequence analysis showed that both LQPSLGFP derived from Se-TAPep 1 and AETGEIKGHY derived from TAPep 1 contained some characteristics of highly active ACE-inhibiting peptides, but the characteristics of LQPSLGFP were more conspicuous, which may be related to its molecular weight and source of mixed peptides. These findings indicated that the selenium-enriched tea mixed peptides had better potential uses than ordinary tea mixed peptides in the preparation of functional food.

A polymer chemical sensor based on lab-on-a-molecule was synthesised by amine-aldehyde polymerisation for selective detection of fluorine ions (F−) and cyanide (CN−). The polymer chemical sensor shows significant absorption and fluorescence changes upon the addition of F− and CN−, which can be observed by the naked eye and optical reactions. The polymer has a higher fluorescence enhancement effect than its monomer and the distance of wavelength of each anion increased which could be applied to better distinguish the two anions.

The structure and hypoglycemic activity of tea polysaccharides has been extensively studied, while there are few reports on the characterization and hypoglycemic activity of dark tea polysaccharides. The crude dark tea polysaccharide (CDTPS) was optimally extracted from Fuzhuan dark tea. Six polysaccharide fractions (namely DTPS-1, DTPS-2, DTPS-3, DTPS-4, DTPS-5, and DTPS-6) were isolated from CDTPS, and their physicochemical, structural, and biological properties were compared and analyzed. The results revealed that the compositions, structural characteristics, and biological properties of the six DTPSs were different. Therein, DTPS-4 and DTPS-6 had looser morphology, faster solubility, and a more stable structure. Additionally, DTPS-4 had the optimum in vitro antioxidant capabilities, and DTPS-6 had the strongest in vitro hypoglycemic capabilities. In addition, a correlation analysis revealed that the molecular weight and uronic acid content were significantly related to their antioxidant and hypoglycemic activities. Our results indicated that DTPS-4 and DTPS-6 could be further developed into functional foods or additives, respectively.

Encrypted storage of optical information has attracted increasing interest for anticounterfeiting, information transmission, and military applications. In this study, an inverse opal-structured titanium dioxide/heptadecafluorodecyltrimethoxysilane (IOS-T/F) panel is developed. Based on a unique wetting-enhanced mechanism of structural color vision derived from a reduced light scattering and strengthened effective refractive index, this panel is capable of reversible writing/erasing and encryption/decryption of optical information. Multiple levels of information can be compiled, concealed, and erased simply using controlled ultraviolet irradiation to form patterned hydrophilic/hydrophobic differences, and the process of revealing or concealing the information only requires a few drops of water or evaporation, respectively. Importantly, the functions of the IOS-T/F panel can be well maintained under harsh conditions, including strongly acidic/alkaline environments or extreme temperatures (from -40 to 80 °C), as well as can be recovered after staining by various pollutants. This system provides simple encryption, rapid decryption, and the ability to store multiple sets of information under diverse application scenarios, which represents a novel material design strategy for security-related applications and smart optical systems.

The introduction of metal particles (MP) in the phase change materials (PCM) realizes the highly efficient thermal energy storage. However, a suitable carrier is necessary for PCM/MP composites for various applications. In this work, the polyethylene glycol (PEG) was used as PCM, five MPs including copper (Cu), aluminum (Al), silver (Ag), iron (Fe), and zinc (Zn) particles were used, and the viscose fabric was selected as a carrier for coating of PEG/MPs. The PEG was blended with different MPs with the same weight ratio of 72.3:23.7. Then, the PEG/MP-coated viscose fabric was prepared by applying PEG/MP composites on the viscose fabric with the same weight ratio of 90:10 and the PEG-coated viscose fabric (86.7:13.3) was set as reference. The phase transition of the prepared PEG/MP composites and the PEG/MP-coated viscose fabrics was investigated via the differential scanning calorimetry (DSC). The thermal behavior of the PEG/MP-coated viscose fabric was investigated via Alambeta device and the T-history method. The results revealed that the enthalpy of all the PEG/MP-coated viscose fabrics were larger than 100J/g. Besides, only the higher theoretical enthalpy of the PEG in the PEG/MP composites was found, and the MPs assisted in the higher crystallization of PEG. Results from the Alambeta device proved that the thermal conductivity was increased when MPs were introduced in the coated viscose fabric. T-history curves of all the PEG/MP-coated viscose fabric revealed that the heating constant of the phase transition stage mainly accounted for the quick heat transfer.

Se-enriched green tea has been widely used as a functional food and disease prevention. In this study, two kinds of homogeneous polysaccharides namely ASe-TPS2 and NSe-TPS2 were obtained from artificial and natural Se-enriched teas with the molecular weights of 6.73 × 103 Da and 2.44 × 105 Da. The structures of ASe-TPS2 and NSe-TPS2 were characterized by monosaccharide composition analysis, partial acid hydrolysis, methylation, FT-IR spectroscopy, NMR spectroscopy, SEM and TGA analysis. It showed that ASe-TPS2 and NSe-TPS2 were acidic polysaccharides containing high amount of uronic acid. The structure of the ASe-TPS2 was mainly composed of β‑D‑(1 → 3)‑Glcp, α‑D‑(1 → 4)‑GalpA, (1 → 4)‑Glcp, α‑L‑(1 → 2)‑Rhap and α‑D‑(1 → 4)‑GalpA, and the non-reducing ends were mainly composed of Araf and Xylp. However, the NSe-TPS2 was mainly composed of β‑D-(1 → 4)‑Glcp and α‑D‑(1 → 4)-GalpA, and the branches were mainly composed of β‑L‑(1 → 2)‑Araf, α‑D‑(1 → 3)‑Galp and β‑L‑(1 → 2)‑Rhap whereas the non-reducing ends were mainly composed of Glcp and Galp residues. These results suggested that the distinction of selenylation methods could present different polysaccharide chain structures.

An N-heterocyclic carbene (NHC)-catalyzed α-functionalization of the in situ activated α,β-unsaturated carboxylic acids bearing γ-H was realized through formal [4 + 2] annulations with o-quinone methides, which paved a new avenue for the assembly and modification of the dihydrocoumarin scaffold in good yields with excellent diastereo- and enantioselectivities.

Qingzhuan tea (QZT) is a unique type of dark tea exclusively produced in Hubei Province of China. In the current study, liquid chromatography-mass spectrometry (LC-MS) coupled with multivariate analysis was applied to characterize the chemical composition of QZT and investigate the effect of QZT processing on its metabolic profile and sensory quality. The contents of polyphenols and flavonoids decreased significantly while the polysaccharides content remained stable, while the theabrownin content inversely increased during QZT processing. LC-MS-based metabolomics analyses revealed that the tea sample after microbial fermentation (MFT) was dramatically different from the sample before microbial fermentation (UFT), while MFT was very similar to QZT. A total of 102 compounds were identified as critical metabolites responsible for metabolic changes caused by QZT processing, with the contents of catechins and flavonoids significantly decreased, and some novel phenolic acids and catechin derivatives were formed. The sensory quality of QZT was mainly formed during microbial fermentation, which greatly reduced the astringency and bitterness of raw tea leaves and produced its characteristic woody and stale aroma as well as mellow taste. These results suggested that microbial fermentation is the critical process in changing the metabolic profile of raw tea leaves and forming the sensory quality of QZT.

A convenient and straightforward strategy for the synthesis of 2,3-disubstituted and 2,3,5-trisubstituted furans via a base-promoted domino reaction of β-keto compounds with vinyl dichlorides is described. This transition-metal-free approach proceeds under operationally simple reaction conditions featuring easily available starting materials, a broad substrate scope, and good functional group tolerance.

So far, the poor stability of Cu2O is still the major challenge in heterogeneous catalysis. Herein, Bougainvillea glabra (B. glabra) derived carbon supported copper composite (Cu2O/BGC) was synthesized in situ by one-pot pyrolysis method. In the synthetic strategy, B. glabra was used as reductant and carbon source simultaneously, and copper nitrate as copper precursor. Cu2O/BGC exhibited a significant enhancement in both catalytic activity and stability for cyclohexane oxidation with tert-butyl hydroperoxide as oxidant under solvent-free condition. Cu2O/BGC with a Cu/C ratio of 0.8 calcined at 800 °C showed the highest catalytic cyclohexane conversion efficiency (77.1%) and cyclohexanone selectivity (68.5%). Its turnover number (TON) is 12.2- and 1.3-fold compared to pure Cu2O and Cu2O/BGC prepared by deposition-reduction method, respectively. Hot filtration experiment confirmed that the sample was a heterogeneous catalyst which could be reused five times without losing its activity.

The performance of disposable face masks in blocking pathogenic microbes mainly relies on the ability of melt-blown fabrics to electrostatically adsorb air droplets. While their easy invalidity in electrostatic effect highly limits their use recyclability, leading to a heavy burden on the surrounding environment due to their decomposing difficulty. Thus, it is urgent to develop reusable air filtration fabrics. In this work, we report a washable electret air-filtering fabrics with negligible cytotoxicity by combining spontaneous polarizing photochromic molecule with electrospinning electret technology. The electrostatic charge and filtration efficiency of the composite fabrics were highly improved compared to the commercial polypropylene melt-blown fabrics. Moreover, due to its electrostatic charge induced by self-polarization, the photochromic Spiropyran(SP)/polystyrene(PS) electret fabrics can maintain high filtration performance (over 95%) towards PM0.3 particles and low air flow resistance (

The chemical profile and taste quality of various dark teas vary considerably due to the huge differences in tea cultivar, processing technology, and production region. Herein, we integrated liquid chromatography-mass spectrometry and electronic tongue to reveal variations in chemical profile and taste quality of five typical dark teas, namely Pu-erh tea (PET), Fuzhuan tea (FZT), Qingzhuan tea (QZT), Kangzhuan tea (KZT), and Liubao tea (LBT), and elucidate chemical basis for their taste quality. The chemical phenotypes of dark teas were classified into FZT, PET, and QZT-KZT-LBT, whereas their taste phenotypes were classified into FZT, PET-QZT, and KZT-LBT. Totally, 49 compounds were identified as differential metabolites, with higher contents of catechins and flavonoid glycosides in FZT, and higher contents of catechin derivatives, flavonoids, and alkaloids in PET. PET had the strongest bitterness and aftertaste-bitterness, while FZT showed the strongest astringency, aftertaste-astringency, and saltiness among five typical dark teas. The bitterness and aftertaste-bitterness of dark teas were negatively associated with polyphenols, flavonoids, and polysaccharides, but positively associated with theabrownins; their aftertaste-astringency was positively related to polyphenols and flavonoids, but negatively related to theabrownins. This study will guide dark tea taste quality control and lay a foundation for comparing their health benefits.

An N-heterocyclic carbene (NHC)-catalyzed formal [4 + 2] synthesis of dihydrocoumarins was realized from saturated carboxylic acids and o-quinone methides via an in situ activation strategy. This protocol results in excellent diastereoselectivity and enantioselectivity and good yields and uses readily available and inexpensive starting materials.

In recent years, selenium-enriched polysaccharides (Se-PS) have been paid more and more attention, and the activity of many Se-PSs has been studied but little on their structure. This study aimed to investigate the activity, structural characterization and present forms of selenium in two different artificial selenium-enriched tea polysaccharides (Se-TPS). The physicochemical analysis showed that both CSe-tps1 and ASe-tps1 were acidic heteropolysaccharides with different monosaccharide composition, molar ratio, and selenium content. Structural investigations including FT-IR, Raman spectra and 1D, 2D NMR analysis revealed that selenium in CSe-tps1 replaced the hydroxyl group at the C-6 position in the polysaccharide with the form of selenyl ester, while most of the selenium in ASe-tps1 replaced the hydroxyl group at the C-1 and C-6 position in the form of the SeH bond on the branch of the polysaccharide. Besides, a series of studies on the structural characteristics of the Congo red test, I2-KI reaction, FESEM, DSC, and XRD analysis showed that the two artificial Se-TPSs had a triple helix structure and more branches. However, there were significant differences in crystal morphology, apparent morphology, heat release ability, and the α-glucosidase inhibition activity. These results indicated that the difference in artificial selenization methods not only made the polysaccharide exhibit different structural characteristics and the hypoglycemic activity, but also had a significant effect on the form of selenium in polysaccharides.

Coating of metal-organic frameworks (MOFs) on flexible substrates is a crucial technology for applications such as purification/separation, sensing, and catalysis. In this work, a facile coordination replication strategy was developed to coat various MOFs onto flexible fibrous materials where a dense layer of an insoluble precursor template, such as a layered hydroxide salt, was first deposited onto a fiber substrate via a mild interfacial reaction and then rapidly transformed into a MOF coating in a ligand solution at room temperature. Spatiotemporal harmonization of solid precursor dissolution and MOF crystallization enabled precise replication of the precursor layer morphology to form a continuous MOF coating composed of intergrown crystals. The resulting flexible, highly robust, and processable fibrous MOF/textile composites demonstrated tremendous potential for industrially relevant applications such as continuous removal of the organosulfur compound dibenzothiophene from simulated gasoline and ammonia capture. This rapid, versatile, eco-friendly, and scalable MOF coating process at room temperature gives rise to new possibilities for preparing MOF-coated functional materials.

Embedding of the functional materials into aerogel powders was realized via the filtration method. In this work, the effect of aerogel on the molecule structure of the embedded polyethylene glycol (PEG) was investigated by dispersing aerogel powders in 20 wt% PEG aqueous solution with subsequent filtration method. The encapsulation of the PEG in the aerogel was characterized by isothermal nitrogen (N2) adsorption/desorption. The structure of the embedded PEG in the aerogel powders was investigated via SEM-EDS, FE-SEM, FT-IR, XRD. TG-DTA, DSC, and leakage test. It was found that the only physical capillary force worked to adsorb PEG molecules from its solution by the aerogel powders. The BET surface area and the DFT pore volume of the PEG/aerogel powders were reduced obviously when compared with pure aerogel powders. The ability of the pores in the aerogel powders ranging from 14 nm to 16 nm to adsorbing the PEG molecules from the water system was weak. The crystallinity of the PEG was significantly reduced because of the limited space for crystal growth, and the decomposed temperature and thermal capacity decreased correspondingly.

Creep and sulfate erosion resistance of concrete are very important in terms of performance of concrete. It is of great interests to combine these two effects together to make a comprehensive investigation of the long-term performance of concrete. However, the research of the concrete creep under both dry-wet circulation and sulfate attack condition has rarely been reported. This paper firstly conducted experiments on the creep of concrete subjected to dry-wet cycle and sulfate attack. The test factors considered in this study include load stress level, sulfate solution concentration, immersion ways including long-term immersion (LM) and dry-wet cycle (DW). Then a creep model of concrete under sulfate corrosion was proposed considering concrete damage by mechanics theory, the prediction from the modified creep model is in good agreement with the test data. Taking into account the dry-wet cycles effects in the BP-KX model of concrete creep, the paper presented a model to predict the creep of concrete under dry-wet circulation and sulfate attack based on the creep model of concrete under sulfate corrosion. Finally, the calculated results from this new model were compared with the test data and the characteristics, shortage and applicability of this new model were also discussed.

Hydrophilic polypyrrole-coated copper nanoneedles (PPy-CuNDs) were synthesized and utilized to construct a superhydrophobic surface on a polyethylene terephthalate fabric (PET) by using the spray-coating technique. The morphology of the as-synthesized PPy-CuNDs can be facilely tuned by changing the concentration of the reducing agent: hydrazine monohydrate. The CuNDs with well-defined nanocrystalline structures and nanoscale thick, rough PPy coating layers were formed simultaneously in one pot. The PPy-CuNDs self-assembled into an entangled, stacking nanocarpet on the surface of the PET fabric, and they eventually formed a reentrant surface texture similar to that of chrysanthemum leaves. The PPy-CuND-PET surface initially showed good superhydrophobic properties, but a fast transition from the superhydrophobic state to the highly adhesive state was observed. The underlying mechanism of this transition and its potential applications were proposed in the context.

Benefiting from the integrated functions of cilia and glomeruli in the olfactory system, animals can discriminate various odors even in hostile environments. Inspired by this synergetic system of response and signal processing units, a sensor chip of graphene oxide (GO) and photonic crystals (PCs) is fabricated. The GO aerogel functions like the olfactory cilia, which effectively captures the analytes and generates abundant sensing signals for recognition; and the PCs act as the olfactory glomeruli, whose periodic structure enables selective enhancement of the fluorescent signals to realize further signal processing. Ten biogenic amines and seven drug amines are effectively discriminated. The integrated sensor strategy of response and signal manipulation units will promote enormous pursuits of rapid clinical diagnosis or intractable pathology analysis.

To make further studies on the difference of cis-nitenpyram analogues, a series of cis-nitenpyram compounds containing a flexible amido segment anchored on tetrahydropyrimidine ring was designed and synthesized. Preliminary bioassays indicate that all the analogues exhibit a mortality of 100% at 100 mg/L, and the analogue 4d shows the best activity against Nilaparvata lugens and Myzus persicae, with a mortality of 100% at 4 mg/L (LC50=0.172 mg/L). The structure activity relationship studies show that insecticidal activities of the analogues are affected by the kinds and size of substituent R. In addition, the molecular docking simulations reveal that compouds 4 with a flexible amido segment on tetrahydropyrimidine ring show their different binding affinities for the nicotinic acetylcholine receptor(nAChR) of insect and compoud 4d shows stronger hydrogen-bonding with nAChR, which may provide the structure-activity relationship observed in vitro.

A novel and sensitive electrochemical sensor for bisphenol A (BPA) determination based on carbon black supporting ferroferric oxide nanoparticles (Fe 3 O 4 NPs-CB) was developed. The Fe 3 O 4 NPs-CB nanocomposite fabricated on the glassy carbon electrode (GCE) demonstrated a high electrocatalytic activity towards the oxidation of BPA. The oxidation overpotentials of BPA decreased significantly and the peak current increased greatly compared with those of Fe 3 O 4 NPs- or CB-modified or bare GCE. Differential pulse voltammetry (DPV) was used as a sensitive analytical method for the determination of BPA, and a much wider linear dynamic range of BPA determination was found between 0.1 nM and 50 μM. The limit of detection (LOD) for BPA was found down to 0.031 nM based on S / N = 3. Fabricated Fe 3 O 4 NPs-CB nanocomposite on GCE displayed several outstanding properties such as good stability, high sensitivity and remarkable repeatability. The described sensor has been used for the determination of BPA in water samples with good recovery, ranging from 93.2% to 104.1%. Additionally, the migration of BPA from PC drinking bottles was evaluated by using water to simulate migration into aqueous and acidic foods.

Introduction In this paper, the authors presented a case of acrylamide poisoning in a middle-aged woman who had underwent unsuccessful cosmetic surgery six years earlier. The victim was told that the product that had been injected into her face was Restylane®, which mainly contained sodium hyaluronate and was the first and only Food and Drug Administration (FDA)-approved dermal filler for lip enhancement in the USA for more than 20years. Widespread facial infections occurred several years post-injection; finally, the victim had to undergo removal surgery. Acrylamide poisoning was strongly suspected based on the victim's clinical manifestation. The product that had been injected into the victim's face was probably polyacrylamide hydrogel-based product, which had been prohibited by the State Food and Drug Administration (SFDA) in China in 2006. To confirm this suspicion, a systematical method was established to differentiate varieties of cosmetic surgery products and identify residential acrylamide. Methods The removed objects, original products and a certified reference sample of Restylane® were collected for examination. A direct microscopic examination was applied as a rapid screening method. Fourier transform infrared (FTIR) microspectroscopy analysis was subsequently performed to distinguish the main components from each sample. Automated solid phase extraction, ultra high performance liquid chromatography (SPE UHPLC) analysis was ultimately utilised and optimised to detect the residual acrylamide. Chromatographic separation was achieved on an ACQUITY UHPLC HSS T3 column. The mobile phase consisted of 0.01% aqueous formic acid solution and acetonitrile. The tunable UV (TUV) detection wavelength was at 202nm. Results The microscopic examination indicated that different samples had different morphological characteristics, depending on their main components. The FTIR spectrum showed that different polymers could be distinguished according to the CO stretching vibration (1655cm −1 ), NH bending vibration (1540cm −1 ) and CO stretching vibration (1078 and 1045cm −1 ). The UHPLC results demonstrated that the calibration curve was linear in the range of 0.5–20.0μg/mL, with a correlation coefficient of 0.999. The average recoveries of the method were 99–107% with an RSD of 1.6–6.3%. The detection limit was 0.1μg/mL (S/N=3). The analytical time was 6min per sample. Acrylamide was detected in the allegedly Restylane® injection. Conclusions This systematical method provides a rapid, accurate and sensitive determination of polyacrylamide and residual acrylamide. The microscopic and FTIR spectroscopic examinations help to verify the existence of polyacrylamide quickly and easily. The optimised SPE UHPLC-TUV method offers a simpler and more sensitive approach to confirm the amount of acrylamide, comparing to the methods in the literature.

Uniform and well-dispersed photoluminescent semiconductor CdSe (Cadmium selenium) QDs (Quantum dots) were in-situ prepared by taking G4.0-NH2PAMAM(polyamidoamine) dendrimers as inner templates in water and methanol respectively. The prepared solutions containing photoluminescent semiconductor CdSe QDs were utilized for detection of unfumed oil fingerprints on tinfoil. The results show that unfumed latent fingerprints treated with prepared CdSe/PAMAM nanocomposites both displayed yellow emission and the latent fingerprints were detected clearly, while treated with CdSe/PAMAM composites in water manifested stronger emission compared with those treated with CdSe/PAMAM composites in methanol; Also, the veins of fingerprints treated with CdSe/PAMAM nanocomposites in methanol became slim because of the dissolution of methanol to oil components in fingerprints.

Two kinds of new immunogens and coating antigens had been designed and synthesised by methods of lively ester (DCC) and carbodiimide (EDC), respectively. Preliminary immunosorbent assays indicated that the two target conjugates presented good inhibition ratio against the haptens of cypermethrin in vivo. The results showed that the best efficient titres of anti-cypermethrin rabbit serum in methods of DCC and EDC were 1:32000 and 1:64000, the IC50 of them were 18.907µg/L and 16.877µg/L against the haptens of cypermethrin, respectively. The data indicated that the anti-cypermethrin antibodies in method of EDC had higher sensitivity and higher selectivity than the anti-cypermethrin antibodies in method of DCC. Thus, we can synthesise antigens and anti-bodies with method of EDC. The antibodies of high quality can be effectively used in the field of the rapid detection of pyrethroid pesticide residues in the research of the reagent strips.

It is challenging to explore a unified solution for the treatment of oily wastewater from complex sources. Thus, membrane materials with flexible separation schemes are highly desired. Herein, we fabricated a smart membrane by electrospinning TiO2 doped polyvinylidene fluoride (PVDF) nanofibers. The as-formed beads-on-string structure and hierarchical roughness of the nanofibers contribute to its superwetting/resisting property to liquids, which is desirable in oil/water separation. Switched simply by UV (or sunlight) irradiation and heating treatment, the smart membrane can realize reversible separation of oil/water mixtures by selectively allowing water or oil to pass through alone. Most importantly, the as-prepared nanofiber membrane possesses outstanding antifouling and self-cleaning performance resulting from the photocatalytic property of TiO2, which has practical significance in saving solvents and recycling materials. This work provides a route for fabricating cost-effective, easily scaled up, and recyclable membranes for on-demand oil/water separation in versatile situations, which can be of great usage in the new green separation technology.

PP/POSS and PP/SiO2 composite non-woven fabrics filled with polyhedral oligomeric silsesquioxanes (POSS) and SiO2 respectively using a convenient blending method were prepared through melt-blown process with corona charging. The morphology of the composite fibers and the distribution of POSS and SiO2 nanoparticles in PP matrix were investigated by field-emission scanning electron microscope (FSEM) and transmission electron microscope (TEM), respectively. POSS and SiO2 can act as nucleating agent and accelerate the crystallization process during nonisothermal cooling. The shear storage modulus G′, loss modulus G″, and complex viscosity η* of non-woven fabric reduce when 1 wt % POSS was added and increase for PP5/POSS composite non-woven fabric compared with pure PP non-woven fabrics. However, all G′, G″ and η* of PP/SiO2 non-woven fabric decrease with increasing SiO2 content owing to plasticization by SiO2. Both stress and elongation at break of the PP/POSS melt-blown non-woven fabrics are improved compared with PP non-woven fabrics, however decrease when SiO2 was added, as compared to the neat PP non-woven fabric. The onset temperature of decomposition for both the PP/POSS and PP/SiO2 composite non-woven fabrics is higher (5–10 °C) than pure PP and char content is increased with increasing POSS and SiO2.

This article mainly focused on the hypoglycemic effects of green tea flower polysaccharides (TFPS) and their possible mechanisms about regulating concentration of blood glucose. An alloxan-induced Sprague–Dawley (SD) rat model was used to observe the change in blood glucose. Inhibition rate of α-amylase and α-glucosidase, and antioxidant ability of TFPS were also tested to explain the possible mechanism. The results showed that TFPS could reduce blood glucose in alloxan-treated rats. TFPS had strong hydrogen donor ability and could protect cell membrane from overoxidation. TFPS could also inhibit the activity of α-amylase and α-glucosidase in vitro. But the inhibition of α-amylase by TFPS was comparatively low. It suggested that TFPS could protect against rapid blood glucose rise in alloxan-induced SD rats. The possible mechanism was that TFPS not only could donate hydrogen to protect SD rats from oxidative damage, but also inhibit digestive enzymes activities.

Yields of tea flower polysaccharides (TFPS) were investigated by ethanol fractional precipitation and stepwise precipitation and the monosaccharide composition of TFPS was investigated by ion chromatography(IC). Furthermore, a preliminary study on bioactivities of TFPS was discussed. The result indicated that the molecular weight distribution of TFPS was wide. Results of ethanol fractional precipitation and stepwise precipitation suggested that most of polysaccharides were precipitated when the final concentration of ethanol was adjusted to 30% (v/v). TFPS contained acid polysaccharides and it was composed of rhamnose, arabinose, galactose, glucose, xylose, mannose, GalA, and GluA with a molar ratio of 4.95:11.57:11.89:4.26:1.31:1.98:8.41:1.0. Furthermore, TFPS exhibited strong inhibitory effect on α-glucosidase and proliferation effect on lymphocytes.

a b s t r a c t In this paper, the composition and biological activities of polysaccharides from tea seed (TSPS) obtained by water extraction were investigated. The properties and chemical compositions of TSPS were analyzed with HPGPC, IC, and IR methods. The results showed that TSPS consisted of three kinds of polysaccharides with the molecular weight of 500 kDa, 130 kDa, and 5 kDa. TSPS consisted of rhamnose, xylose, arabinose, glucose and galactose, GalA, GulA, with a molar ratio of 4.9:1.7:11.1:27.2:14.0:3.4:1, sugar backbone of TSPS might consist of glucose, but branched chain may consist of rhamnose, xylose, arabinose, and galactose. The IR spectrum of TSPS revealed the typical characteristics of polysaccharides and protein. TSPS significantly inhibited the growth of K562 cells, especially, at the concentration of 50 g/ml; the inhibition activity of TSPS was the highest with an inhibition ratio beyond 38.44 ± 2.22% (P < 0.01). TSPS with high concentrations (100, 200 and 400 g/ml) had higher proliferation effect on lymphocyte. Results of these studies demonstrated that the polysaccharide had a potential application as natural antitumor drugs.

A new method for the determination of tea polysaccharide (TPS) in green tea (Camellia sinensis) leaves has been developed. The method was based on the enhancement of resonance light scattering (RLS) of TPS in the presence of cetylpyridinium chloride (CPC)-NaOH system. Under the optimum conditions, the RLS intensity of CPC was greatly enhanced by adding TPS. The maximum peak of the enhanced RLS spectra was located at 484.02 nm. The enhanced RLS intensity was proportional to the concentration of TPS in the range of 2.0-20 μg/ml. It showed that the new method and phenol-sulfuric acid method give some equivalent results by measuring the standard compounds. The recoveries of the two methods were 96.39-103.7% (novel method) and 100.15-103.65% (phenol-sulfuric acid method), respectively. However, it showed that the two methods were different to some extent. The new method offered a limit of detection (LOD) of 0.047 μg/ml, whereas the phenol-sulfuric acid method gives a LOD of 1.54 μg/ml. Interfered experiment demonstrated that the new method had highly selectivity, and was more suitable for the determination of TPS than phenol-sulfuric method. Stability test showed that new method had good stability. Moreover, the proposed method owns the advantages of easy operation, rapidity and practicability, which suggested that the proposed method could be satisfactorily applied to the determination of TPS in green tea.

In this paper, the crude polysaccharides from the flowers of tea plant (Camellia sinensis) (TFPS) extracted with hot water were fractionated on a DEAE Sepharose FF chromatography to get TFPS1 with a yield of 18%. The properties and chemical compositions of TFPS1 were analyzed with GC, HPGPC, IC, IR methods and its morphology was observed with atomic force microscopy (AFM). The results showed that TFPS1 was a neutral glycoprotein conjugate with a molecular weight 500 kDa. The alanine, threonine, glycine, valine, serine, histidine, glutamic acid, histidine and tyrosine were found in TFPS1 and the total content was 2.03%. TFPS1 was consisted of rhamnose, arabinose, mannose, glucose and galactose, with a mole ratio of 1.0:2.9:0.5:1.3:3.3. Sugar backbone of TFPS1 may consist of glucose and galactose, but branched chain may consist of arabinose, galactose and rhamnose. The IR spectrum of TFPS1 revealed the typical characteristics of polysaccharides and protein. TFPS1 was spherical particle structure with a diameter of 50–70 nm.

A chitosan-degrading fungus, BSF114, was isolated from soil. The culture preparation showed strong chitosanolytic enzyme activity at optimum pH 4.0 and optimum temperature of 60 degrees C after 36-40 h fermentation. The rapid decreased viscosity of chitosan solutions at early stage of reaction suggested an endo-type cleavage of the polymeric chitosan chains. To identify the isolated fungus, molecular biological and morphological methods were used. The fungal internal transcribed spacer (ITS) region 1 was amplified, sequenced, and then compared with related sequences in the GenBank database using BLAST. The phylogenetic relationships were then analyzed, and the results showed that the fungus belongs to Aspergillus fumigatus. Morphological observations were also used to confirm the above conclusion. The chitooligosaccharides (COS) obtained through hydrolyzing the colloidal chitosan showed A. fumigatus BSF114 is suitable for degrading chitosan and producing chitooligosaccharides on a large scale. High concentrations of the COS (1000 and 500 microg/mL) significantly proliferated mice marrow cells.

Four flavones (flavone, 7-hydroxyflavone, chrysin, and baicalein) sharing the same B- and C-ring structure but a different numbers of hydroxyl groups on the A-ring were studied for their affinities for BSA and HSA. The hydroxylation on ring A of flavones increased the binding constants (K(a)) and the number of binding sites (n) between flavones and serum albumins. The affinities of 7-hydroxyflavone for BSA and HSA were about 800 times and 40 times higher than that of flavone, respectively. It appears that the optimal number of hydroxyl groups introduced to the ring A of flavones is one. As more hydroxyl groups were introduced to positions at C-5, C-6, and/or C-7 of flavones, the affinities for serum albumins decrease. The critical energy transfer distances (R(0)) between the hydroxylated flavones (1-3 OH on the ring A) and serum albumins decreased with the increasing affinities for serum albumins.

A direct procedure for the determination of total polysaccharides (TPS) in Camellia sinensis was set up based on the modified phenol-sulfuric acid method. The monosaccharide composition of TPS was analyzed by GC. Based on the results of GC, model monosaccharide mixtures were made which provided an adequate standard for this procedure. Through single-factor and orthogonal (L934) experiments, the experimental conditions such as the volume of phenol, the volume of concentrated sulfuric acid, the reaction time, and the incubation temperature, were optimized. The highest sensitivity of absorbance was obtained when the volume of concentrated sulfuric acid, the volume of phenol (6%), and the incubation temperature were 2.5 ml, 0.2 ml, and 50?C, respectively. Under optimum conditions, the prepared samples were determined satisfactorily, with the recovery from 100.2% to 103.7%, and a relative standard deviation (RSD) of 2.1%. Overall, the modified method is easily operated, rapid, sensitive and accurate. A similar procedure can be applied to the determination of other plant polysaccharides as well. .

A continuous adsorption study in a fixed-bed column was carried out by using phoenix tree leaf powder as an adsorbent for the removal of methylene blue (MB) from aqueous solution. The effect of flow rate, influent MB concentration and bed depth on the adsorption characteristics of adsorbent was investigated at pH 7.4. Data confirmed that the breakthrough curves were dependent on flow rate, initial concentration of dye and bed depth. Four kinetic models, Thomas, Adams–Bohart, Yoon–Nelson and Clark, were applied to experimental data to predict the breakthrough curves using nonlinear regression and to determine the characteristic parameters of the column that are useful for process design, while a bed-depth service time analysis (BDST) model was used to express the effect of bed depth on breakthrough curves and to predict the time needed for breakthrough at other conditions. The Thomas and Clark models were found suitable for the description of whole breakthrough curve, while the Adams–Bohart model was only used to predict the initial part of the dynamic process. The data were in good agreement with the BDST model. It was concluded that the leaf powder column can be used in wastewater treatment.

The interaction between flavonoids and proteins has attracted great interest among researchers. However, few reports have focused on the structure-affinity relationship of flavonoids binding to proteins. This work mainly concerns the effect of glycosylation of flavonoids on the affinities for BSA. Four flavonoid aglycones (baicalein, quercetin, daidzein, and genistein) and their monoglycosides (baicalin, quercitrin, daidzin, and puerarin, genistin) and another poly glycoside (rutin) are studied for their affinities for BSA. The glycosylation of flavonoids significantly affects the quenching/binding process. In general, the glycosylation of flavonoids lowers the affinity for BSA by 1 to 3 orders of magnitude depending on the conjugation site and the class of sugar moiety. The glucopyranosylation (daidzin and genistin) of flavonoids lowered the affinity for BSA by 5-10 times. Rhamnosylation (quercitrin) of flavonoids, however, lowered the affinity for BSA by 5600 times. This result partly supports that flavonoid aglycones are more easily absorbed than flavonoid glycosides. Higher binding affinities for BSA are associated with higher antioxidant activities for flavonoids. Glycosylation also decreases the hydrophobicity of flavonoids, and hydrophobic interaction may play an important role in binding flavonoids to proteins.

A neutral polysaccharide, coded as NTPS-1, was obtained from the crude tea polysaccharide (NTPS) of green tea ( Camellia sinesis ) by a DEAE-Sepharose fast flow column. The polysaccharide appeared to be homogenous with the weight of 21,247 Da by the high performance gel permeation chromatography (HPGPC) analysis. The NTPS-1 was found to consist of galactose. The structure of NTPS-1 was characterized by infrared (IR) spectrum, gas chromatography (GC), periodate oxidation, Smith degradation, 1D NMR and 2D NMR spectroscopy. It was found that NTPS-1 was a galactan consisting of β-(1→4)-linked galactopyranosyl units.

A reversed-phase liquid chromatographic method was developed for the quantitative determination of three major hypotensive compounds, namely geniposidic acid, chlorogenic acid, and geniposide in the bark of Eucommia ulmoides. Soxhlet extraction of GPA, GPS, and CA from E. ulmoides was optimized according to the Taguchi experimental design. Maximum global yields were obtained using the following conditions: extraction temperature, 80?C; extraction time, 1 h; number of extractions, three; solvent volume, 16 ml/g of sample; and 50% ethanol concentration in water. Optimal conditions of separation and detection were achieved on a Diamonsil ODS C18 column (150 mm ? 4.6 mm, 5 ?m) with a linear gradient of methanol and 0.04% aqueous phosphoric acid (v/v) at a flow rate of 1.0 ml/min and detection wavelength of 240 nm. All calibration curves showed good linearity (r2 > 0.999) within test ranges. The relative deviation of this method was less than 3% for intra- and inter-day assays, and the recovery percentage of the method was 95-104%, with a relative standard deviation (R.S.D.) of less than 5%. The current assay method was used for quantitative determination of geniposidic acid, chlorogenic acid, and geniposide in five samples of E. ulmoides with different age. The results indicate that the developed method could be readily utilized as a quality control method in working with E. ulmoides.

Uniform and well-dispersed photoluminescent semiconductor CdS (cadmium sulfide) QDs (quantum dots) were in situ prepared inside Generation 4.0-NH 2 PAMAM (polyamidoamine) dendrimers in methanol, methanol and water mixed solutions of volume ratio 1:9, respectively. The prepared solutions containing photoluminescent semiconductor CdS QDs were utilized for detection of cyanoacrylate ester fumed fingerprints on tinfoil. The results show that fumed latent fingerprints treated with prepared CdS/PAMAM nanocomposites in methanol, 1:9 methanol:water mixed solutions emit pale yellow–green and orange luminescence respectively under ultraviolet excitation of 365 nm from an UV LED. Fumed fingerprints were successfully detected with good resolving rate and the mechanism was studied in detail.

Comparison analysis of linear least square method and nonlinear least square method for estimating the kinetic parameters was made using the experimental column data of methylene blue (MB) adsorption onto zeolite at different flow rates and initial concentration. The data were fitted to Thomas model equations using linear and nonlinear regressive analysis, respectively. The error analysis was performed. Present investigation showed that the linear and nonlinear methods are both suitable to predict the breakthrough curves using Thomas model parameters and the nonlinear method is better.

Biomaterials are being extensively used in various biomedical fields; however, they are readily infected with microorganisms, thus posing a serious threat to the public health care. We herein presented a facile route to the antibacterial modification of an important A-B-A type biomaterial using poly (ethylene glycol) methyl ether (mPEG)- poly(e-caprolactone) (PCL)-mPEG as a typical model. Inexpensive, commercial bis(2-hydroxyethyl) methylammonium chloride (DMA) was adopted as an antibacterial unit. The effective synthesis of the antibacterial copolymer mPEG-PCL-∼∼∼-PCL-mPEG (where ∼∼∼ denotes the segment with DMA units) was well confirmed by FTIR and (1)H NMR spectra. At an appropriate modification extent, the DMA unit could render the copolymer mPEG-PCL-∼∼∼-PCL-mPEG highly antibacterial, but did not largely alter its fascinating intrinsic properties including the thermosensitivity (e.g., the body temperature-induced sol-gel transition), non-cytotoxicity, and controlled drug release. A detailed study on the sol-gel-sol transition behavior of different copolymers showed that an appropriate extent of modification with DMA retained a sol-gel-sol transition, despite the fact that a too high extent caused a loss of sol-gel-sol transition. The hydrophilic and hydrophobic balance between mPEG and PCL was most likely broken upon a high extent of quaternization due to a large disturbance effect of DMA units at a large quantity (as evidenced by the heavily depressed PCL segment crystallinity), and thus the micelle aggregation mechanism for the gel formation could not work anymore, along with the loss of the thermosensitivity. The work presented here is highly expected to be generalized for synthesis of various block copolymers with immunity to microorganisms. Light may also be shed on understanding the phase transition behavior of various multiblock copolymers.

Se-polysaccharides from Se-enriched tea leaves were purified by DEAE-sepharose fast flow gel column (2.5×60cm) and three polysaccharide fractions (Se-TPS1, Se-TPS2, and Se-TPS3) were isolated and purified with yields of 6.5, 37.14, and 8.57%, respectively. The average sizes of Se-TPS1 and Se-TPS2 were determined by HPGPC system, with molecular weights of 1.1×10(5) and 2.4×10(5)Da, respectively. Se-TPS3 was a polysaccharide polymer with two peaks with molecular weights of 9.2×10(5) and 2.5×10(5)Da. Monosaccharide components analysis by ion chromatography revealed Se-polysaccharides were acidic polysaccharoses and different from each other in monosaccharide kinds and molar ratio. Elements of Se, C, H, N, S, and 14 kinds of mineral elements were analyzed by AFS, EA, and ICP-AES, respectively. Spectral analysis (IR and UV) indicated Se-polysaccharides were typical glycoproteins. Morphological analyses of the samples were determined by SEM and AFM. In addition, the DPPH and superoxide radicals scavenging activities were also discussed to assess antioxidant activities of the samples, and Se-polysaccharides showed higher antioxidant activities compared to the ordinary polysaccharides.

An improved thermal decomposition method was used to directly prepare water-soluble Fe3O4 magnetic nanoparticles (MNPs) with relatively higher quality via reductive decomposition of ferric acetylacetonate [Fe(acac)3], in the presence of benzyl ether and phenol, in which inexpensive phenol acted as reducing agent and stabilizer, produce the semi phenol-benzoquinone coated on the Fe3O4 and make the Fe3O4·MNPs water-soluble and the colloidal solution stable. By changing the molar ratio of phenol to Fe(acac)3 and reaction time, the size of Fe3O4·MNPs could be varied from 19.3 ± 4.4 nm to 9.7 ± 1.5 nm, with the saturation magnetizations in the range of 51.3–62.9 emu/g.

A novel polypropylene/Polyhedral oligomeric silsesquioxanes (PP/POSS) composite unwoven fabric with permanent electret was prepared through melt-blown process with corona charging. Field-emission scanning electron microscope (FESEM) and wide-angle X-ray diffraction (WAXRD) were employed to investigate the morphology of the composite fibers and the distribution of POSS nanoparticles on the surface of the fibers, respectively. POSS acted as nucleating agent and accelerated the crystallization process during nonisothermal cooling. The utmost stable charge density of PP/POSS melt-blown unwoven fabric was improved by 78.4% compared with the neat PP unwoven fabric. The maximum value of collection efficiency measured by monodisperse polystyrene aerosol (PSL) (particle size: 0.3 μm) collection could reach 97.36% for PP/POSS composite melt-blown unwoven fabric, which improved by 9% compared with neat PP melt-blown unwoven fabric. Moreover, both stress and elongation at break of the PP/POSS melt-blown unwoven fabrics were improved compared with PP unwoven fabric.

Based on the characteristics of concrete sulfate attack, a two-dimension cellular automata model is developed based on the fundamental theory of cellular automata to simulate the penetration process of sulfate ion in concrete under sulfate attack. The evolution rules of the cellular automata model are validated by comparison with the calculation results from the Fick's second law. Meanwhile, it discusses the essential distinction between the cellular automata model and the Fick's second law in calculation method and characteristics of the sulfate ion corrosion in concrete. By further analysis of the characteristics of sulfate ion's diffusion in different corrosion time in concrete, the calculated results derived from the cellular automata model, in which the changes of sulfate ion's jump probabilities are taken into account, show better correlation with the experimental data than that from the Fick's second law, thereby a new approach is provided for analysis of concrete durability.

The effect of solution temperature and the determination of the kinetic parameters of methylene blue (MB) adsorption onto cereal chaff were performed to understand the adsorption mechanism. The pseudo-second order kinetic model was fitted to the experimental data and found it was good to predict the adsorption behavior using nonlinear regressive method, suggesting that the mechanism may be a chemisorption process. The activation energy of adsorption (Ea) was 22.4 kJ mol-1. The thermodynamic parameters (ΔG0, ΔH0, and ΔS0) were also determined from the temperature dependence. The results showed that the process of adsorption MB was spontaneous and endothermic process and an increase in temperature favored the adsorption. The diffusion coefficient was also estimated.