Metal element-fusion peptide heterostructured nanocoatings endow polyetheretherketone implants with robust anti-bacterial activities and in vivo osseointegration.

Polyetheretherketone (PEEK), renowned for its exceptional mechanical properties and bio-stability, is considered a promising alternative to traditional metal-based implants. However, the inferior bactericidal activity and the limited angiogenic and osteogenic properties of PEEK remain the three major obstacles to osseointegration in vivo. To overcome these obstacles, in this work, a versatile heterostructured nanocoating was conceived and equipped on PEEK. This nanocoating was designed to endow PEEK with the ability of photo-activated pathogen disinfection, along with enhanced angiogenesis and osteogenesis, effectively addressing the triple-barrier challenge towards osseointegration. The crafted nanocoating, encompassing diverse nutritional metal elements (Fe3+, Mg2+, and Sr2+) and a fusion peptide adept at promoting angiogenesis and osteogenesis, was seamlessly decorated onto PEEK. The engineered implant exhibited an antibacterial activity of over 94% upon near-infrared illumination by virtue of the photothermal conversion of the polyphenol nanocoating. Simultaneously, the decorated hierarchical nanocoatings synergistically promoted cellular adhesion and proliferation and up-regulated angiogenesis-/osteogenesis-associated cytokine expression in endothelial/osteoblast cells, resulting in superior angiogenic differentiation and osteoinductive capability in vitro. Moreover, an in vivo assay in a rabbit femoral defect model revealed that the decorated implant can achieve ameliorative osseointegrative fixation. Collectively, this work offers a practical and instructive clinical strategy to address the triple-barrier challenge associated with PEEK-based implants.

Achieving Clearance of Drug-Resistant Bacterial Infection and Rapid Cutaneous Wound Regeneration Using an ROS-Balancing-Engineered Heterojunction.

Intractable infected microenvironments caused by drug-resistant bacteria stalls the normal course of wound healing. Sono-piezodynamic therapy (SPT) is harnessed to combat pathogenic bacteria, but the superabundant reactive oxygen species (ROS) generated during SPT inevitably provoke severe inflammatory response, hindering tissue regeneration. Consequently, an intelligent nanocatalytic membrane composed of poly(lactic-co-glycolic acid) (PLGA) and black phosphorus /V2C MXene bio-heterojunctions (2D2-bioHJs) is devised. Under ultrasonication, 2D2-bioHJs effectively eliminate drug-resistant bacteria by disrupting metabolism and electron transport chain (ETC). When ultrasonication ceases, they enable the elimination of SPT-generated ROS. The 2D2-bioHJs act as a "lever" that effectively achieves a balance between ROS generation and annihilation, delivering both antibacterial and anti-inflammatory properties to the engineered membrane. More importantly, in vivo assays corroborate that the nanocatalytic membranes transform the stalled chronic wound environment into a regenerative one by eradicating the bacterial population, dampening the NF-κB inflammatory pathway and promoting angiogenesis. As envisaged, this work demonstrates a novel tactic to arm membranes with programmed antibacterial and anti-inflammatory effects to remedy refractory infected wounds from drug-fast bacteria.

Domino index: A rapid quantification tool for the domino effect in chemical plants.

The severity of industrial accidents involving domino effects is widely acknowledged in chemical and process industries. The interdependence of installations and complexity of layouts pose significant challenges for the rapid quantitative assessment of domino effects in large chemical plants. In this study, a set of domino indices was introduced to measure the extent to which a given installation triggered and propagated domino effects, as well as to assess the overall domino effect in a specified area. An accelerated algorithm for domino accident modelling was developed based on Monte Carlo simulations to calculate the domino index. This algorithm can simulate all potential domino accident propagation pathways and the failure frequencies of installations. Two case studies, derived for a hypothetical chemical plant and actual oil-storage facilities, were examined to evaluate the applicability of the method. Furthermore, the method was validated using conditional probability calculations and vertex metrics. The results demonstrated that the proposed domino index is a useful tool for rapidly quantifying domino effects and that it can assist in identifying critical installations, designing plant layouts, and screening hazardous areas. The method and indices can provide guidance for the prevention of severe domino accidents.

Low androgen levels induce ferroptosis of rat penile cavernous endothelial cells.

Background: Endothelial dysfunction caused by low androgen levels in penile tissue can lead to erectile dysfunction. The exact mechanism of endothelial dysfunction has not been thoroughly studied. Objective: The study sought to verify whether low androgen levels induce ferroptosis of endothelial cells in rat penile tissue. Methods: Rat penile cavernous endothelial cells (CP-R133) were divided into a no-androgen group (Dihydrotestosterone (DHT): 0 nmol/L), very low-androgen group (DHT: 0.1 nmol/L), low-androgen group (DHT: 1 nmol/L), DHT = 10 nmol/L group, DHT (0 nmol/L) + ferrostatin-1 (Fer-1) group, DHT (0.1 nmol/L) + Fer-1 group, DHT (1 nmol/L) + Fer-1 group, DHT (10 nmol/L) + Fer-1 group. Cell viability, intracellular ferrous ion (Fe2+), malondialdehyde (MDA), GSH into oxidized glutathione (GSSG), reactive oxygen species (ROS), nitric oxide (NO), transferrin receptor 1 protein (TfR1), solute carrier family 7 member 11 (SLC7A11), glutathione peroxidase 4 (GPX4), acyl-CoA synthetase long-chain family member 4 (ACSL4), endothelial nitric oxide synthase (eNOS), and phospho-eNOS (p-eNOS) were detected. Outcomes: Low androgen levels could induce ferroptosis of rat penile cavernous endothelial cells in vivo by upregulating the expressions of TfR1 and ACSL4 and downregulating the expressions of SLC7A11 and GPX4. Results: Cell viability, the levels of glutathione (GSH), NO, SLC7A11, GPX4, and p-eNOS/eNOS in the DHT = 0 nmol/L group were lower than those in the other groups (P < .05). The levels of Fe2+, ROS, MDA, GSSG, TfR1, and ACSL4 in the DHT = 0 nmol/L group were higher than those in the other groups (P < .05). Cell viability and the levels of GSH, NO, SLC7A11, GPX4, and p-eNOS/eNOS in the DHT = 1 nmol/L group were lower than those in the DHT (1 nmol/L) + Fer-1 group, DHT = 10 nmol/L group, and DHT (10 nmol/L) + Fer-1 group (P < .05). The levels of Fe2+, ROS, MDA, GSSG, TfR1, and ACSL4 in the DHT = 1 nmol/L group were higher than those in the DHT (1 nmol/L) + Fer-1 group, DHT = 10 nmol/L group, and DHT (10 nmol/L) + Fer-1 group (P < .05). Clinical Implications: A ferroptosis inhibitor might be a novel drug for treating erectile dysfunction caused by low androgen level. Strengths and Limitations: The results of this study need to be further confirmed in in vitro and in human studies. Meanwhile, further investigation is needed to clarify whether low androgen levels affect ferroptosis of rat penile cavernous smooth muscle and nerve cells. Conclusion: Low androgen levels can induce ferroptosis of endothelial cells in rat penile tissue. Inhibition of ferroptosis can reverse endothelial dysfunction caused by low androgen levels.

Preparation of poly(sodium 4-styrene sulfonate) grafted magnetic chitosan microspheres for adsorption of cationic dyes.

A novel adsorbent with high adsorption capacity to remove cationic dyes was synthesized. Sodium 4-styrene sulfonate (SSS) was grafted polymerization on the surface of magnetic chitosan microspheres via -NH2/S2O82- surface initiating system, obtaining MCS-g-PSSS microspheres. The grafted microsphere was characterized by Fourier transforms infrared spectroscopy, X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, vibration sample magnetometer and the Brunauer-Emmett-Teller. Cationic dyes were adsorbed by MCS-g-PSSS and methylene blue(MB) was acted as a typical example. The adsorption performance was explored by varying experimental conditions. The results showed the maximal adsorption capacity was 989 mg/g at pH 1 at 25 °C. The pseudo-second order model was found to be applicable for the adsorption kinetics. The adsorption capacity increased with rising temperature and it decreased owing to adding of ions. The adsorption isotherms were the best fitted by Langmuir. MCS-g-PSSS for MB showed high adsorption capacity due to the strong electrostatic interactions and π-π stacking, which was explained by FTIR and XPS and was verified by DFT calculations. The degree of adsorption spontaneity increased with rising the temperature. The grafted MCS-g-PSSS microspheres had high adsorption capacity for various kinds of cationic dyes and excellent for remove MB in the aqueous solution.

[Spatiotemporal Distributions and Ecological Risk Assessments of Typical Antibiotics in Surface Water of Taihu Lake].

Using solid phase extraction-high performance liquid chromatography tandem mass spectrometry, antibiotics belonging to four classes (i.e. sulfonamides, quinolones, tetracycline, and macrolides) in the surface water of Taihu Lake were monitored monthly for a year. Moreover, the potential ecological risks of antibiotics in Taihu Lake were assessed. During the one-year monitoring, all the eighteen target antibiotics were detected to some extent in the surface water. The detection rates of five sulfonamides (sulfamethoxazole, sulfathiazole, sulfadiazine, sulfadimethazine, and trimethoprim) were higher than 50%. The concentrations of quinolones in the surface water were relatively higher. The average and medium concentrations of ciprofloxacin were 13.0 ng·L-1 and 13.5 ng·L-1, respectively. There were significant differences in the antibiotic pollution during the different months, with the average concentrations of the target antibiotics ranging from 7.3 to 33.5 ng·L-1. The concentration levels were lower from June to October, while higher concentrations were observed from February to May and in November. In the surface water of Taihu Lake, the spatial variations of antibiotics among the 20 sampling sites were not significant, with the average concentrations ranging from 13.0 to 14.3 ng·L-1. During the one-year monitoring, the rates of medium and high risks that the antibiotics posed to algae reached 57.5%. The ecological risks of antibiotics were more severe in April and November, and the quinolones may be the dominant risk factor. This issue should be carefully considered by management authorities.

Preparation of sulfonate chitosan microspheres and study on its adsorption properties for methylene blue.

Dyes bring a lot of benefits to our lives, however, as common organic pollutants, they have destructive influences on the environment. Firstly, glutaraldehyde crosslinked chitosan microspheres (GCS) are prepared via inverse-phase suspension polymerization. Then, GCS microspheres are acted as the base material, ammonium persulfate (Aps) as the initiator, sodium styrene sulfonate (SSS) as anionic functional monomer, functional microspheres (GCS-g-PSSS) are prepared by surface grafting polymerization. The amount of monomer and Aps, temperature and reaction time is respectively explored. The chemical structures and physicochemical properties of functional microspheres were characterized by FT-IR, zeta potential, scanning electron microscope and X-ray photoelectron spectroscopy. The adsorption kinetic at different temperature and initial concentration is studied and fitted. The adsorption isotherms of GCS-g-PSSS for MB are explored at different pH, temperature and salinity. The adsorption capacity of GCS-g-PSSS for MB is 820.1 mg/g at 318 K. The adsorption isotherms at different temperature are fitted by Langmuir, Freundlich, Dubinin-Radushkevich and Temkin. Thermodynamic parameters imply that adsorption is a spontaneous and endothermic process. And this adsorbent has good reusability. The adsorption ability of GCS-g-PSSS microspheres is also excellent for other cationic dyes. Thus, GCS-g-PSSS microspheres might serve as a promising adsorbent for contaminated water scavenging.

[Temporal and Spatial Occurrence of NSAIDs in Taihu Lake and Relevant Risk Assessment].

Non-steroidal anti-inflammatory drugs (NSAIDs) are a class of drug residues with a high frequency of detection in Taihu Lake. However, little information is available about the occurrence of typical NSAID mixtures in Taihu Lake as a whole across the four seasons. Therefore, for each season, the concentrations of five typical NSAIDs including diclofenac, ibuprofen, indomethacin, naproxen, and ketoprofen were monitored in the water of Taihu Lake by the method of high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) at 19 transects covering the entire lake. The temporal and spatial occurrence of NSAID mixtures in the water of Taihu Lake and their correlation with environmental factors were analyzed, and the mixture risk quotient (MRQ) model was also used to assess the ecological risk of the NSAID mixtures. The research results are as follows:① The concentrations of NSAIDs in the northern, western, and eastern waters of Taihu Lake are at a higher level compared to those in the central waters. Ketoprofen is the main contributor to the contamination of NSAID mixtures in all regions of Taihu Lake. ② The concentrations of NSAIDs in Taihu Lake are higher in summer (15.9-134.3 ng·L-1) and autumn (16.4-144.6 ng·L-1) but lower in spring (25.3-72.5 ng·L-1) and winter (14.6-57.4 ng·L-1), being significantly correlated with water conductivity and pH, respectively. ③ The MRQ model evaluation reveals that there are nine sections in Taihu Lake showing a high ecological risk (MRQ>1) from NSAID mixtures throughout the year. The ecological risk of the NSAID mixtures at a medium or high level (MRQ>0.1) lasts for a long time spanning the spring, summer, and autumn seasons, of which the risk is greatest in autumn. Overall, the pollution caused by the NSAID mixtures in the water of Taihu Lake should not be ignored, and especially great attention should be paid to the pollution in autumn.

Effect of pidotimod combined with azithromycin on children with mycoplasma pneumonia and the expression levels of IL-10 and G-CSF in serum.

This study explored the effect of pidotimod combined with azithromycin on children with mycoplasma pneumonia and the expression of interleukin-10 (IL-10) and granulocyte colony-stimulating factor (G-CSF) in serum. The clinical data of 149 children with mycoplasma pneumonia from May 2014 to May 2018 in Zhangqiu District Maternal and Child Health Care Hospital were collected. Among them, 70 children treated with azithromycin sequential therapy were the control group, and 79 children treated with the combination of pidotimod and azithromycin were the observation group. Double antibody sandwich enzyme-linked immunosorbent assay (ELISA) was used to determine the expression levels of IL-10 and G-CSF in serum before and after treatment. Pearson's correlation coefficient was used to analyze the correlation between IL-10 and G-CSF in serum. The total effective rate in the observation group (94.94%) was significantly higher than that in the control group (81.43%) (P<0.05). There was no significant difference in the expression levels of IL-10 and G-CSF between the two groups before treatment (P>0.05). The expression levels of IL-10 and G-CSF in the two groups after treatment were significantly lower than those before treatment (P<0.05). After treatment, the expression levels of IL-10 and G-CSF in serum in the observation group were significantly lower than those in the control group. There was a significant positive correlation between the expression levels of IL-10 and G-CSF before and after treatment in the observation group (P<0.05), and a significant positive correlation between the expression levels of IL-10 and G-CSF before and after treatment in the control group (P<0.05). Compared with sequential treatment with azithromycin alone, pidotimod combined with azithromycin significantly reduced the expression levels of IL-10 and G-CSF in serum of children with mycoplasma pneumonia, improved the curative effect and reduced the occurrence of adverse reactions, which has high application value in clinic.

Evaluation of the Removal of Potassium Cyanide and its Toxicity in Green Algae (Chlorella vulgaris).

To evaluate the removal of potassium cyanide (KCN) and its toxicity in algae, an initial comprehensive analysis was performed with Chlorella vulgaris. The algae showed potential removal capability for KCN, with the maximal removal rate of 61%. Moreover, effects of KCN on growth, cellular morphology and antioxidant defense system of C. vulgaris were evaluated. Cell number and chlorophyll a content decreased in most cases, with the maximal inhibition rates of 48% and 99%, respectively. The 100 mg L- 1 KCN seriously damaged the algal cell membrane. Additionally, activity of superoxide dismutase (SOD) was promoted by KCN exposure among 0.1-50 mg L- 1 and inhibited by 100 mg L- 1 KCN, while the malondialdehyde (MDA) content gradually decreased in C. vulgaris with increasing exposure concentration compared to the control. The present study reveals that C. vulgaris is useful in bio-treatment of cyanide-contaminated aquatic ecosystem, except in high concentrations which would cause overwhelming effects.

Enhanced tunable Raman soliton source between 1.9 and 2.36 µm in a Tm-doped fiber amplifier.

We demonstrate generation of widely tunable femtosecond pulses by utilizing the soliton self-frequency shift effect in a Tm-doped fiber amplifier, seeded by dispersion managed mode-locked Tm oscillator. The monochromatic soliton pulses with a duration of the order of 100 fs have been obtained and its wavelength can be adjusted continuously in the range of 1.9-2.36 µm by varying the pump power. The efficiency of Raman conversion is as high as 97% with output power up to 1.16 W. The experimental results are in good agreement with numerical simulations of pulse propagation in Tm-doped fiber amplifier.

1 µJ, sub-300 fs pulse generation from a compact thulium-doped chirped pulse amplifier seeded by Raman shifted erbium-doped fiber laser.

We present a compact thulium-doped chirped pulse amplifier producing 241 fs pulses with 1 µJ energy. The system is seeded with the Raman shifted soliton generated by the combination of an erbium-doped femtosecond laser and a nonlinear fiber. The Tm-doped large mode area fiber yields output power of 71 W, corresponding to pulse energy of 2.04 µJ, with a slope efficiency of 52.2%. The amplified pulses have been compressed to a duration time of 241 fs, using a folded Treacy grating setup. The pulse energy is measured to be 1.02 µJ, corresponding to a peak power of ~3 MW. To the best of our knowledge, this is the highest average power and pulse energy generated from an all-fiber, Raman shifted soliton seeded thulium-doped chirped pulse amplifier system.

High-power linearly-polarized picosecond thulium-doped all-fiber master-oscillator power-amplifier.

We demonstrated a linearly-polarized picosecond thulium-doped all-fiber-integrated master-oscillator power-amplifier system, which yielded 240 W of average output power at 127 MHz repetition rate. The seed source is a passively mode-locked polarization-maintaining thulium-doped all-fiber oscillator with a nearly transform-limited pulse duration of 10 ps. In combination with a pre-chirp fiber having a positive group velocity dispersion and a three stage polarization-maintaining thulium-doped all-fiber amplifier, output pulse energies up to 1.89 µJ with 42 kW pulse peak power are obtained without the need of complex free-space stretcher or compressor setups. To the best of our knowledge, this is the highest average output power ever reported for a picosecond all-fiber-integrated laser at 2 µm wavelength region.

High-power, high signal-to-noise ratio single-frequency 1 µm Brillouin all-fiber laser.

We demonstrate a high-power, high signal-to-noise ratio single-frequency Brillouin all-fiber laser with high slope efficiency at 1 µm wavelength. The laser is pumped by an amplified single-longitudinal-mode distributed Bragg reflector fiber laser with a linewidth of 33 kHz. By optimizing the length of the Brillouin ring cavity to 10 m, stable single-frequency Brillouin fiber laser is obtained with 3 kHz linewidth owing to the linewidth narrowing effect. At the launched pump power of 2.15 W, the Brillouin fiber laser generates maximum output power of 1.4 W with a slope efficiency of 79% and the optical signal-to-noise ratio of 77 dB.

Dissipative soliton resonance and reverse saturable absorption in graphene oxide mode-locked all-normal-dispersion Yb-doped fiber laser.

We observed dissipative soliton resonance phenomenon in a graphene oxide mode-locked Yb-doped fiber laser, which delivered square-shaped pulse of 0.52 ns~60.8 ns and single pulse energy of 159.4 nJ at 1064.9 nm. The 3 dB-bandwidth of Lorentz-shaped spectrum was 0.19 nm. We pointed out that the reverse saturable absorption played a big role in generating square-shaped or flat-top pulses, which verified by additional simulation work.

High-power operation of silica-based Raman fiber amplifier at 2147 nm.

We demonstrated a 2147 nm silica-based Raman fiber amplifier with output power of 14.3 W directly pumped with a 1963 nm CW thulium-doped all-fiber MOPA. The 1963 nm thulium-doped all-fiber MOPA is seeded with a 2147 nm thulium-doped all-fiber laser at the same time. The Raman Stokes power shift from 1963 nm to 2147 nm is accomplished in a piece of 50 m silica-based highly nonlinear fiber (HNLF). The conversion efficiency was 38.5% from 1963 nm to 2147 nm in the HNLF. The output power achieved was only currently limited by available 1963 nm input power and the architecture has significant scaling potential. To the best of our knowledge, this is the highest power operation of a Raman fiber amplifier at >2 µm wavelength region.

High power mid-infrared supercontinuum generation in a single-mode ZBLAN fiber with up to 21.8 W average output power.

We report high power mid-infrared (mid-IR) supercontinuum (SC) generation in a single-mode ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF) fiber with up to 21.8 W average output power from 1.9 to beyond 3.8 µm pumped by amplified picosecond pulses from a single-mode thulium-doped fiber (TDF) master oscillator power amplifier (MOPA). The optical-optical conversion efficiency from the 793 nm pump laser of the last stage thulium-doped fiber amplifier (TDFA) to mid-IR SC output is 17%. It is, to the best of our knowledge, the highest average power mid-IR SC generation from a ZBLAN fiber to date.

[Chemical constituents of bark of Taxus chinensis var. mairei].

OBJECTIVE: To study the chemical constituents in the bark of Taxus chinensis var. mairei collected from southeast of China. METHODS: Chemical constituents were isolated and purified by column chromatography, Prep-TLC, and preparative HPLC. The structures were identified on the basis of 1D-and 2D-NMR spectral analysis. RESULTS: Twelve taxane diterpenoids were isolated from the bark of Taxus chinensis var. mairei grown in southeast of China. They were identified as: taxagifine (1), decinnamoyltaxagifine (2), 19-debenzoyl-19-acetyltaxinine M(3), 9-dihydro-13-acetyl-baccatin III (4), 7, 9-dideacetylbaccatin IV (5), 1,3-dihydro-taxinine (6), taxumairol C (7), taxezopidine J (8), 7-xylosyl-10-deacetyl-taxol A (9),10-deacetyltaxol (10), taxicin II (11), and 2alpha, 7beta, 10beta-triacetoxy-5alpha, 13alpha-dihydroxy-2 (3 --> 20) abeotaxa-4 (20), 11-dien-9-one (12). CONCLUSION: Compounds 1, 2, 4 - 6, 8, 9, 11 and 12 are obtained from this plant for the first time. Compound 7 is obtained from the bark of Taxus chinensis var. mairei for the first time.

210 W single-frequency, single-polarization, thulium-doped all-fiber MOPA.

A high-power single-frequency, single-polarization, thulium-doped all-fiber master-oscillator power-amplifier (MOPA) is demonstrated by using all-polarization-maintaining (all-PM) thulium-doped fiber and all-PM-fiber components. The MOPA yielded 210 W of single-frequency, linear-polarized laser output at central wavelength of 2000.9 nm with a polarization extinction ratio (PER) of >17 dB. No indication of stimulated Brillouin scattering (SBS) could be observed at the highest output power level, and the output power was only currently limited by available pump power. To the best of our knowledge, this is the first demonstration of average output power exceeding 200 W from a single-frequency, single-polarization, thulium-doped all-fiber laser at 2 µm wavelength region.

Stable passively Q-switched and gain-switched Yb-doped all-fiber laser based on a dual-cavity with fiber Bragg gratings.

We demonstrate a stable passively Q-switched and gain-switched Yb-doped all-fiber laser cladding-pumped by a continuous fiber-coupled 976 nm laser diode. By use of an all-fiber dual-cavity, the efficient elements of the laser mainly include the fiber Bragg gratings and rare-earth doped fiber, allowing the oscillator to be integrated in a compact size with reliable and stable output. In this scheme, an efficient laser output with 45 ns pulse width, 62 µJ pulse energy, and 1.4 kW peak power operating at 1081 nm was obtained. To the best of our knowledge, this is the minimum pulse width in this similar kind of all-fiber configuration at present. Sequential nanosecond pulses were obtained at the repetition rate of several to tens of kHz with the variation of the diode pumping power. Effects of laser parameters such as pump power, cavity length, external-cavity wavelength, and FBG reflectivity on laser performance were also presented and discussed.