Degradation of reactive red (B-3BF) dye wastewater using UV irradiation (254/185 nm) with sodium persulfate in a pilot UV device.

Two low-pressure ultraviolet (UV) lamps at 185/254 nm with sodium persulfate in a pilot UV device were utilized for the degradation of reactive red (B-3BF) dye wastewater compared with two UV lamps at 185/185 nm and two UV lamps at 254/254 nm. The degradation performances of UV irradiation (254/185 nm) with sodium persulfate under different degradation times, flow rates, initial pH, initial Na2S2O8 concentrations and initial dye concentrations were investigated. The experimental results illustrated that the degradation percentage of B-3BF dye could reduce to 90.42% with the energy consumption of 85.1 kWh/kg and the residual dye concentration of 1.92 mg/L by UV irradiation (254/185 nm) with initial Na2S2O8 concentration of 1.5 mmol/L and initial dye concentration of 20 mg/L. In addition, degradation performance of B-3BF dye wastewater by UV irradiation (254/185 nm) with sodium persulfate was more effective than those of UV irradiation (254/254 nm) and UV irradiation (185/185 nm). Therefore UV irradiation (254/185 nm) with sodium persulfate was promising for the degradation of B-3BF dye wastewater.

Molecular Evidence of Structural Changes in Silk Using Unlimited Degradation Mass Spectrometry.

Proteomics has important uses in archeological science because it can distinguish species, reveal the evolution of paleontology, and provide biological evidence of historical events. However, this technique still has full potential in the study of silk aging mechanisms. In this work, we propose a strategy combining unlimited degradation with mass-spectrometry-based proteomics techniques, which interpret protein fragmentation propensity and secondary structure changes by detecting content changes of specific peptide groups in complex proteomes. This approach was employed to study the conformational changes in silk microscopic crystals after heat treatment. Combining conventional mechanics and crystallographic characterization, a thermal aging degradation mechanism model was proposed. At the same time, it explained the interesting problem that the crystallinity remained unchanged, but the mechanical properties decreased significantly. Focusing on the unlimited degradation process, this method will be widely applicable to the study of silk and wool aging processes and regenerated silk fibroin.

Nanoarchitectured Graphene Organic Framework for Drug Delivery and Chemo-photothermal Synergistic Therapy.

The combination of phototherapy and chemotherapy has received extensive attention in the field of cancer therapy. Hence, graphene organic framework (GOF) with a large d-spacing was prepared by solvothermal method, and a novel nanocomposite based on bovine serum albumin (BSA) and the anticancer drug doxorubicin (DOX) was developed, which effectively achieved a photothermal-chemotherapy synergistic treatment. When the feeding ratio was 1:1.6, the DOX loading capacity was 18.51%, and the GOF-BSA/DOX nanocomposite possessed unobvious pH response characteristic, as well as the cumulative release of DOX reached 54.17% at 42°C in the acidic environment (pH = 5.0). The nanocarriers also showed excellent photothermal property and photothermal stability in vitro. In addition, under 808 nm near-infrared laser (NIR) irradiation, the GOF-BSA/DOX nanocomposites generated a large amount of heat, which significantly enhanced the synergistic antitumor effect of in vitro photothermal-chemotherapy. Furthermore, the GOF-BSA/DOX nanocomposites exhibited significantly increased cytotoxicity in the NIR compared with chemotherapy or photothermal therapy alone, suggesting that the combination of chemotherapy and photothermal therapy has excellent antitumor capacity. Therefore, porous GOF nanocarriers may have great potential in combined anti-tumour therapy.

Review of Graphene-Based Textile Strain Sensors, with Emphasis on Structure Activity Relationship.

Graphene-based textile strain sensors were reviewed in terms of their preparation methods, performance, and applications with particular attention on its forming method, the key properties (sensitivity, stability, sensing range and response time), and comparisons. Staple fiber strain sensors, staple and filament strain sensors, nonwoven fabric strain sensors, woven fabric strain sensors and knitted fabric strain sensors were summarized, respectively. (i) In general, graphene-based textile strain sensors can be obtained in two ways. One method is to prepare conductive textiles through spinning and weaving techniques, and the graphene worked as conductive filler. The other method is to deposit graphene-based materials on the surface of textiles, the graphene served as conductive coatings and colorants. (ii) The gauge factor (GF) value of sensor refers to its mechanical and electromechanical properties, which are the key evaluation indicators. We found the absolute value of GF of graphene-based textile strain sensor could be roughly divided into two trends according to its structural changes. Firstly, in the recoverable deformation stage, GF usually decreased with the increase of strain. Secondly, in the unrecoverable deformation stage, GF usually increased with the increase of strain. (iii) The main challenge of graphene-based textile strain sensors was that their application capacity received limited studies. Most of current studies only discussed washability, seldomly involving the impact of other environmental factors, including friction, PH, etc. Based on these developments, this work was done to provide some merit to references and guidelines for the progress of future research on flexible and wearable electronics.

Doxorubicin-loaded pH-responsive nanoparticles coated with chlorin e6 for drug delivery and synergetic chemo-photodynamic therapy.

The integration of chemotherapy drugs and photosensitizers to form versatile nanoplatforms for achieving chemo-photodynamic synergetic therapy has shown great superiority in tumor theranostic applications. We constructed pH-responsive nanoparticles (DOX/PB NPs) encapsulating the chemotherapeutic drug doxorubicin (DOX) into the cores of PLGA NPs coated with bovine serum albumin (BSA) via a water-in-oil (W/O/W) emulsion method. A simple and efficient chemo-photodynamic synergetic nanoplatform (DOX/PB@Ce6 NPs) was obtained by the adsorption of photosensitizer chlorin e6 (Ce6) onto the surface of the DOX/PB NPs. With optimal size, pH-responsive drug release behavior and excellent singlet oxygen production, the DOX/PB@Ce6 NPs have the potential to enhance anti-tumor efficiency. The cellular uptake, cytotoxicity, chemo-photodynamic synergetic effect and biocompatibility of the NPs were evaluated based on HeLa cells via in vitro experiments. The in vitro chemo-photodynamic synergetic experiments indicated that the DOX/PB@Ce6 NPs had remarkable cancer cell killing efficiency under laser irradiation. Notably, by hemolysis assay, all the NPs displayed excellent blood compatibility and were expected to be applicable for intravenous injection. In summary, the designed DOX/PB@Ce6 NPs multifunctional theranostic nanoplatform had excellent reactive oxygen species generation and would be a potential therapeutic platform for chemo-photodynamic synergetic therapy.

Versatile Nanoplatform Loaded with Doxorubicin and Graphene Quantum Dots/Methylene Blue for Drug Delivery and Chemophotothermal/Photodynamic Synergetic Cancer Therapy.

A versatile platform for nanodrug delivery and synergetic therapy is a promising therapeutic pattern for antitumor treatment in clinical biology. Here, we innovatively encapsulated graphene quantum dots (GQDs) or methylene blue (MB) together with doxorubicin (DOX) into the cores of poly lactic-co-glycolic acid (PLGA) nanoparticles coated with bovine serum albumin (BSA) based on the emulsion method to synthesize core-shell structure nanoparticles (GQDs@DOX/PB and MB@DOX/PB NPs). The GQDs@DOX/PB NPs exhibited excellent photothermal properties and stability under 808 nm laser irradiation. The in vitro chemophotothermal synergetic experiments manifested that the GQDs@DOX/PB NPs effectively cause the thermal ablation of tumor cells under NIR laser irradiation. Meanwhile, the in vitro chemophotodynamic synergetic experiments revealed that the MB@DOX/PB NPs could produce reactive oxygen species and showed outstanding antitumor efficacy under 660 nm laser irradiation. Consequently, the pH-responsive multifunctional nanoparticles prepared by a facile strategy have a high tumor cell-killing efficacy, manifesting excellent potential in synergistic therapy.

Tailored monoclonal antibody as recognition probe of immunosensor for ultrasensitive detection of silk fibroin and use in the study of archaeological samples.

The ultrasensitive detection of fibroin in unearthed silk relics has great significance for investigating the origin and transmission of silk. In this study, an anti-fibroin monoclonal antibody was successfully prepared through animal immunization. Next, a label-free electrochemical immunosensor was fabricated using layer-by-layer self-assembly technology, and an indirect enzyme-linked immunosorbent assay (ELISA) was proposed. The two methods exhibited excellent sensitivity and specificity in the detection of silk fibroin, while the immunosensor showed a wider quantitative detection range (0.1-100 ng mL-1) and a lower detection limit (0.051 ng mL-1) than ELISA (10-100 ng mL-1 and 8.71 ng mL-1). Furthermore, the performance of the immunosensor was superior in archaeological sample detection. Taking advantage of the well-prepared monoclonal antibody, the two proposed immunological assays demonstrate tremendous potential for the ultrasensitive detection of silk fibroin, which can make great contributions to exploring the origin and transmission routes of ancient silks.

pH and Thermal Dual-Responsive Graphene Oxide Nanocomplexes for Targeted Drug Delivery and Photothermal-Chemo/Photodynamic Synergetic Therapy.

The development of versatile nanoplatforms with efficient tumor-targeting properties and synergistic therapeutic strategies to realize effective antitumor efficiency are highly anticipated in the field of cancer therapy. Herein, we innovatively synthesized targeted nanocomplexes (NCGO-FA) with nanoscale structures by a modified Hummers' method and then used these nanocomplexes to separately load the doxorubicin (DOX) and methylene blue (MB) via π-π stacking, electrostatic attractions, and/or hydrophobic interactions, forming NCGO@DOX-FA and NCGO@MB-FA nanoplatforms. The results demonstrated that the NCGO-FA nanocomplexes have an ultrahigh surface area, a high-load content of drugs, targeting specificity, and a good photothermal conversion efficiency and photostability. Meanwhile, after loading the nanoplatforms with DOX or MB, NCGO-FA delivered drugs into cancer cells by folic acid (FA) receptors and triggered the drug release by heat and in acidic tumor environments. More importantly, compared with individually applied photothermal therapy, photodynamic therapy, or chemotherapy, the photothermal-chemo or photothermal-photodynamic synergistic therapy with the NCGO@DOX-FA or NCGO@MB-FA nanoplatform exhibits a remarkable synergistic effect, resulting in a distinguished antitumor efficiency. Consequently, this work proposes a facile and versatile method to construct a dual-responsive versatile nanoplatform that combines photothermal-chemo and photodynamic therapies, and these nanoplatforms have excellent application prospects for tumor therapy.

Synthesis of polymer-functionalized nanoscale graphene oxide with different surface charge and its cellular uptake, biosafety and immune responses in Raw264.7 macrophages.

Polymer-functionalized graphene oxide (GO) has superior properties such as large surface area, extraordinary mechanical strength, high carrier mobility, good stability in physiological media and low cytotoxicity, making it an attractive material for drug and gene delivery. Herein, we successfully synthesized GO with an average size of 168.3 nm by a modified Hummers' method. Branched polyethylenimine (PEI) and 6-armed polyethylene glycol (PEG) functionalized GO complexes (GO-PEI and GO-PEG) with different zeta potentials of 47.2 mV and -43.0 mV, respectively, were successfully synthesized through amide linkages between the COOH groups of GO and the NH2 groups of PEI and PEG. Then, the interactions between GO-PEI and GO-PEG complexes and Raw264.7 mouse monocyte-macrophage cells were investigated. The GO-PEI and GO-PEG complexes could both be internalized by Raw264.7 cells. However, compared with the GO-PEG complex, the GO-PEI complex showed higher intracellular delivery efficiency in Raw264.7 cells. Moreover, it was found that the GO-PEI complex not only gathered in endosomes but also in the cytoplasm, whereas GO-PEG gathered in endosomes only. The MTT tests showed that both GO-PEI and GO-PEG complexes exhibited very low cytotoxicity towards Raw264.7 cells when at a low concentration. The cellular immune response test demonstrated the GO-PEG complex enhanced the secretion of IL-6, illustrating it was more stimulus towards macrophage cells. The above results indicated that the GO-PEI complex, with a positive surface charge, demonstrated better potential to be used in effective drug and gene delivery.

MoS2 quantum dots@TiO2 nanotube composites with enhanced photoexcited charge separation and high-efficiency visible-light driven photocatalysis.

MoS2 quantum dots (QDs) that are 5 nm in size were deposited on the surface of ultrathin TiO2 nanotubes (TNTs) with 5 nm wall thickness by using an improved hydrothermal method to form a MoS2 QDs@TNT visible-light photocatalyst. The ultrathin TNTs with high percentage of photocatalytic reactive facets were fabricated by the commercially available TiO2 nanoparticles (P25) through an improved hydrothermal method, and the MoS2 QDs were acquired by using a surfactant-assisted technique. The novel MoS2 QDs@TNT photocatalysts showed excellent photocatalytic activity with a decolorization rate of 92% or approximately 3.5 times more than that of pure TNTs for the high initial concentration of methylene blue solution (20 mg l-1) within 40 min under visible-light irradiation. MoS2 as the co-catalysts favored the broadening of TNTs into the visible-light absorption scope. The quantum confinement and edge effects of the MoS2 QDs and the heterojunction formed between the MoS2 QDs and TNTs efficiently extended the lifetime of photoinduced charges, impeded the recombination of photoexcited electron-hole pairs, and improved the visible-light-driven high-efficiency photocatalysis.

Interactions between rGO/TNT nanocomposites and cells: Regulation of cell morphology, uptake, cytotoxicity, adhesion and migration.

Reduced graphene oxide/titanium dioxide nanotube (rGO/TNT) composites have superior properties, such as a large surface area, extraordinary mechanical strength, high carrier mobility, etc. However, the biosafety and biocompatibility of these composites, such as their influences on cell viability and cell functions, which are of paramount importance, are still not fully addressed. In this study, rGO/TNT nanocomposites were successfully synthesized through a modified hydrothermal treatment method. Then, the interactions between the rGO/TNT nanocomposites and Raw264.7 mouse monocyte-macrophage cells were further investigated. The results show that the rGO/TNT nanocomposites could be internalized by Raw264.7 cells and mainly gathered inside the cytoplasm. No rGO/TNT nanocomposites were observed in the nucleus. Moreover, the rGO/TNT nanocomposites exhibited low cytotoxicity toward Raw264.7 cells at a lower dose, though they may exhibit cytotoxicity to some extent at very high concentrations. In addition, the uptake of the nanocomposites influenced the cell cytoskeleton organization, while the cell adhesion and migration abilities were also impaired.

Application of Electron Paramagnetic Resonance and Solid-state 13C Nuclear Magnetic Resonance of Cross-polarization/Magic Angle Spinning to Study Enzymatic Degradation of Silk Fabrics.

The enzymatic degradation of silk by protease XIV has been investigated by using scanning electron microscopy (SEM), Fourier transfer infrared spectroscopy (FTIR), solid-state 13C nuclear magnetic resonance of cross-polarization/magic angle spinning (13C CP/MAS solid state NMR) and electron paramagnetic resonance (EPR). Micro-morphology of protease XIV aged samples showed that microfilaments were stripped out from the surface of silk fibers. The results of FTIR and 13C CP/MAS solid-state NMR indicated that the enzymatic degradation process could be divided into two stages. The EPR spectra indicated that the enzymatic degradation process was related to the free radical with the g-factor value of 2.0043. We also proposed that at the first degradation stage, the free radicals were apt to lose activities due to the loose structure of the non-crystalline region; at the second degradation stage, the free radicals produced in the crystalline region tended to be stored.

Preparation of the MoS2/TiO2/HMFs ternary composite hollow microfibres with enhanced photocatalytic performance under visible light.

A novel route for synthesis of MoS2/TiO2/hollow microfibers (HMFs) ternary composite photocatalyst using sol-gel method combined with high temperature calcination under a nitrogen circumstances was reported for the first time. The morphology, structure and optical properties of the novel MoS2/TiO2/HMFs photocatalysts were fully characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), specific surface area (BET) and thermogravimetric analysis (TG). The photocatalytic activities were evaluated by photodegradating Methylene blue (MB) and Rhodamine B (RB) under visible light irradiation. The results showed the MoS2/TiO2/HMFs ternary composite hollow microfibre photocatalysts had a purification of more than 98.7% for MB and RB of simulating wastewater, and acquired the superior synergistic effect of adsorption and catalysis for organic pollutants. That's because the sensitization of MoS2 enlarged the wavelength response range to the visible region of the solar spectrum, the HMFs could beneficially increase adsorption capability for organic pollutants, and the mixed crystalline phase of TiO2 accelerated the decomposition of organic pollutant. A detailed study of involved active species unraveled the mechanism regarding photocatalysis. So, the synergistic photocatalytic effect of HMFs, TiO2 and MoS2 was very important and significant for wastewater treatment or prevention of air pollution.

Effect of breastfeeding on childhood BMI and obesity: the China Family Panel Studies.

The objective of this study is to investigate the effect of breastfeeding on childhood obesity in China.We used data collected from the China Family Panel Studies, an ongoing, prospective, and nationwide longitudinal study to explore the extensive and dynamic social changes in China. A total of 7967 children were included in the analysis. Duration of breastfeeding was first treated as a continuous variable and subsequently dichotomized into ever versus never, ≥6 months versus <6 months, ≥8 months versus < 8 months, and ≥12 months versus <12 months. Multiple imputation was conducted and regressions with propensity score matching were performed. We also performed quantile regression to examine whether breastfeeding has an effect on childhood obesity among children with a specific quantile of body mass index (BMI).Consistent with findings from recent studies, in both adjusted and adjusted regressions, we did not find any statistically significant effect of breastfeeding on reducing the risk of obesity (unadjusted odds ratio, OR = 1.02, 95% confidence interval, CI 0.99, 1.05, P = 0.12; adjusted OR 1.01, 95% CI 0.98, 1.05, P = 0.36) or excessive weight (unadjusted OR = 1.01, 95% CI 0.99, 1.03, P = 0.26; adjusted OR = 1.00, 95% CI 0.98, 1.02, P = 0.90). Results were similar using various dichotomization of duration of breastfeeding. Quantile regression revealed that longer duration of breastfeeding is associated with higher BMI among children with small to medium quantile of BMI.Our findings echo recent research and caution against any population-wide strategy in attempting to reduce overweight and obesity through promotion of breastfeeding.

Resonance Raman spectroscopy and density functional theory calculation study of photodecay dynamics of tetra(4-carboxyphenyl) porphyrin.

The 397.9 nm, 416.0 nm and 435.7 nm resonance Raman spectra were acquired for meso-tetrakis(4-carboxyphenyl)porphyrin (TCPP) in tetrahydrofuran solution, and the Raman effect of relaxation dynamics was analyzed according to Herzberg-Teller (vibronic coupling) contributions. Density functional calculations were done to help the elucidation of the Soret (B(x) and B(y)-band) electronic transitions and the corresponding photo relaxation dynamics of TCPP. The spectra indicate that the Franck-Condon region photo relaxation dynamics upon S(0) → S(4) electronic transition are predominantly along the totally symmetric C(m)-ph stretch and Porphin ring breath stretch, and simultaneously along the asymmetric ν(C(m)-Phenyl) + δ(N-H) and ν(C(α)-C(m)-C(α))(as) + def (pyr) vibrational relaxation processes. The excited state structural dynamics of TCPP determined from the resonance Raman spectra show that the internal conversion between the B(y) and B(x) electronic states occurs in tens of femtoseconds, and the electronic relaxation dynamics were firstly interpreted taking into account the time-dependent wave packet theory and Herzberg-Teller (vibronic coupling) contributions.

Photodecay dynamics of octaethylporphine in the condensed phase explored via resonance Raman spectroscopy and density functional theory calculation.

Resonance Raman spectra of free-base octaethylporphine (OEP) were obtained with 368.9 nm, 397.9 nm and 416.0 nm excitation wavelengths, and density functional calculations were done to help the elucidation of Soret (B(x) and B(y)-band) electronic transitions and the corresponding photo relaxation dynamics of OEP. The RRs indicate that the Franck-Condon region photo relaxation dynamics upon S(0)→S(8) electronic transition is predominantly along the totally symmetric C(m)C(α) stretch, the C(ß)C(ß) stretch, and simultaneously along the asymmetric δ(pyr deformation),γ(CH(2)) vibrational relaxation processes. The excited state structural dynamics of OEP determined from resonance Raman spectra show that the internal conversion between B(y) and B(x) electronic states occurs in tens of femtoseconds and the electronic relaxation dynamics were firstly interpreted with account of the time-dependent wave packet theory and Herzberg-Teller (vibronic coupling) contributions.

Excited state structural dynamics of tetra(4-aminophenyl)porphine in the condensed phase: resonance Raman spectroscopy and density functional theory calculation study.

Resonance Raman spectra (RRs) of tetra(4-aminophenyl) porphine (TAPP) were obtained, and density functional calculations were done to help the elucidation of the photorelaxation dynamics of Soret (B(x) and B(y) band) and Q(y) electronic transitions. The RRs indicate that the photorelaxation dynamics for the S(0) --> S(3) excited electronic state is predominantly along the totally symmetric porphin ring C(beta)=C(beta) + C(m)C(alpha) stretch, C(m)-ph stretch, and simultaneously along the asymmetric nu(C(m)C(alpha))(as) and nu(C(alpha)C(beta))(as) relaxation processes leading to Q(y) while that for S(0) --> S(2) is predominantly along the porphin ring C(beta)=C(beta) + C(m)C(alpha) stretch and simultaneously along the asymmetric nu(C(m)C(alpha))(as) + nu(C(alpha)C(beta))(as) relaxation processes leading to thermal equilibrium in Q(x). The excited state structural dynamics of TAPP determined from RRs shows that internal conversion B(x) --> Q(y) electronic relaxation occurs in tens of femtoseconds and the short-time dynamics were first interpreted with account of the time-dependent wave packet theory and Herzberg-Teller contributions.

Excited state structural dynamics and Herzberg-Teller coupling of tetraphenylporphine explored via resonance Raman spectroscopy and density functional theory calculation.

Resonance Raman spectra of free-base tetraphenylporphine (TPP) were obtained with 397.9, 416, and 435.7nm excitation wavelengths and density functional calculations were done to elucidate the electronic transitions and the resonance Raman spectra (RRs) of TPP. The RRs indicate that the Franck-Condon region photodynamics for S(0)-->S(4) electronic state is predominantly along the C(m)-ph stretch while that for S(0)-->S(3) electronic state is predominantly along the porphin ring C(beta)C(beta) stretch. Non-totally symmetric vibrational modes were regularly presented in resonance Raman spectra: the shorter the excitation wavelengths were, the stronger intensity the modes had, which can be interpreted in terms of electric dipole transition moments caused by Franck-Condon and Herzberg-Teller coupling. Four non-total symmetry vibrational mode upsilon(52,)upsilon(64), upsilon(97) and upsilon(130) in A(2) irreducible representative of TPP were observed in 397.9, 416 and 435.7nm resonance Raman spectrum. With the shorter wavelength laser excitations at 416 or 397.9nm, the A(2) vibrational modes show more enhanced Raman intensity by comparison with those in the TPP spectrum excited at 435.7nm.