Accumulation of polyethylene microplastics induces oxidative stress, microbiome dysbiosis and immunoregulation in crayfish.

Microplastics have become a worldwide pollutant, widely discovered in soil, air and aquatic environment. Microplastics have been found in habitats where crayfish (Procambarus clarkii) cultivated, but the impact of microplastics on crayfish remains unclear. In this study, after 21-day dietary exposure, polyethylene (PE) particles were found to accumulate in intestine, hepatopancreas, gills and hemolymph of crayfish. Furthermore, PE particles can still be detected in these tissues after a 7-day depuration in clean water. PE retained in these tissues caused oxidative stress responses, as indicated by the change of oxidative-stress-related index, such as the increase of H2O2 level and SOD activity. PE exposure also caused hemocytic encapsulation in crayfish hepatopancreas and increase of mucus secretion in intestine. Moreover, PE exposure affected the microbiota balance in crayfish, by reducing the total microbiota abundance and altering the proportions of many bacterial families. Interestingly, results showed that PE exposure led to of lower numbers of hemocytes and declination of phenoloxidase activity. Finally, PE exposure induced the expression of immune-related genes, including transcription factors and antimicrobial peptides. Taken these together, we conclude that PE microplastics exert considerable toxic effects on crayfish and are a potential threat to crayfish aquaculture and consumption. This study provides basic toxicological data toward quantifying and illuminating the impact of PE microplastics on freshwater animals.

Ultrasonic-Assisted Method for the Preparation of Carbon Nanotube-Graphene/Polydimethylsiloxane Composites with Integrated Thermal Conductivity, Electromagnetic Interference Shielding, and Mechanical Performances.

Due to the rapid development of the miniaturization and portability of electronic devices, the demand for polymer composites with high thermal conductivity and mechanical flexibility has significantly increased. A carbon nanotube (CNT)-graphene (Gr)/polydimethylsiloxane (PDMS) composite with excellent thermal conductivity and mechanical flexibility is prepared by ultrasonic-assisted forced infiltration (UAFI). When the mass ratio of CNT and Gr reaches 3:1, the thermal conductivity of the CNT-Gr(3:1)/PDMS composite is 4.641 W/(m·K), which is 1619% higher than that of a pure PDMS matrix. In addition, the CNT-Gr(3:1)/PDMS composite also has excellent mechanical properties. The tensile strength and elongation at break of CNT-Gr(3:1)/PDMS composites are 3.29 MPa and 29.40%, respectively. The CNT-Gr/PDMS composite also shows good performance in terms of electromagnetic shielding and thermal stability. The PDMS composites have great potential in the thermal management of electronic devices.

An epidemiological survey of gastroesophageal reflux disease at the digestive endoscopy center in Guangzhou.

OBJECTIVE: This study aims to investigate the detection rates, common symptoms and risk factors of gastroesophageal reflux disease (GERD), and laryngopharyngeal reflux disease (LPRD) at the digestive endoscopy center. METHODS: A multicenter cross-sectional survey conducted at three hospitals and a total of 565 eligible participants were enrolled. All the patients completed routine ENT examination, gastroscopy, gastroesophageal reflux questionnaire (GerdQ), reflux symptom index (RSI) and a self-designed 25-item symptoms table survey. RESULTS: Among the 565 eligible participants, the detection rates of GERD and LPRD were 18.41% (104/565) and 9.91% (56/565), respectively. The detection rate of GERD combined with LPRD was 3.19% (18/565). Among GERD and LPRD patients, males (vs. females), middle-aged and elderly patients (vs. young people), BMI ≥ 24.0 kg/m2 (vs. BMI < 24.0 kg/m2), with current smoking history (vs. no smoking), and current drinking history (vs. no drinking), lying down immediately after meal (vs. no lying down immediately after meal) were significantly higher (all p < 0.05). The most common extraesophageal symptoms in patients with GERD were dry mouth (66.35%), globus sensation (56.73%), dry throat and pharyngeal itching (55.77%). The most common extraesophageal symptoms in patients with LPRD were globus sensation (91.07%), dry throat and pharyngeal itching (83.93%), and dry mouth (82.14%). CONCLUSION: GERD and LPRD had a high detection rate at the digestive endoscopy center in Guangzhou, China. Older age, BMI ≥ 24.0 kg/m2, smoking and drinking history were risk factors for both GERD and LPRD. Neither GerdQ nor RSI scores included common extraesophageal symptoms.

A multi-controlled drug delivery system based on magnetic mesoporous Fe3O4 nanopaticles and a phase change material for cancer thermo-chemotherapy.

Herein a novel multi-controlled drug release system for doxorubicin (DOX) was developed, in which monodisperse mesoporous Fe3O4 nanoparticles were combined with a phase change material (PCM) and polyethylene glycol 2000 (PEG2000). It is found that the PCM/PEG/DOX mixture containing 20% PEG could be dissolved into water at 42 °C. The mesoporous Fe3O4 nanoparticles prepared by the solvothermal method had sizes of around 25 nm and exhibited a mesoporous microstructure. A simple solvent evaporation process was employed to load the PCM/PEG/DOX mixture on the mesoporous Fe3O4 nanoparticles completely. In the Fe3O4@PCM/PEG/DOX system, the pores of the Fe3O4 nanoparticles were observed to be filled with the mixture of PCM/PEG/DOX. The Fe3O4@PCM/PEG/DOX system showed a saturation magnetization value of 50.0 emu g-1, lower than 71.1 emu g-1 of the mesoporous Fe3O4 nanoparticles, but it was still high enough for magnetic targeting and hyperthermia application. The evaluation on drug release performance indicated that the Fe3O4@PCM/PEG/DOX system achieved nearly zero release of DOX in vitro in body temperature, while around 80% of DOX could be released within 1.5 h at the therapeutic threshold of 42 °C or under the NIR laser irradiation for about 4 h. And a very rapid release of DOX was achieved by this system when applying an alternating magnetic field. By comparing the systems with and without PEG2000, it is revealed that the presence of PEG2000 makes DOX easy to be released from 1-tetradecanol to water, owing to its functions of increasing the solubility of DOX in 1-tetradecanol as well as decreasing the surface tension between water and 1-tetradecanol. The novel drug release system shows great potential for the development of thermo-chemotherapy of cancer treatment.

Quaternized chitosan/polyvinyl alcohol anion exchange membrane enhanced by functionalized attapulgite clay with an ionic "chain-ball" surface structure.

Biomass chitosan has garnered considerable interest for alkaline anion exchange membranes (AEMs) due to its eco-friendly and sustainable characteristics, low reactant permeability and easily modifiable nature, but it still faces the trade-off between high hydroxide conductivity and sufficient mechanical properties. Herein, a novel functionalized attapulgite clay (f-ATP) with a unique ionic "chain-ball" surface structure was prepared and incorporated with quaternized chitosan (QCS)/polyvinyl alcohol (PVA) matrix to fabricate high-performance composite AEMs. Due to the strengthened interfacial bonding between f-ATP nanofillers and the QCS/PVA matrix, composite membranes are synergistically reinforced and toughened, achieving peak tensile strength and elongation at break of 24.62 MPa and 33.8 %. Meanwhile, abundant ion pairs on f-ATP surface facilitate ion transport in the composite AEMs, with the maximum OH- conductivity of 46 mS cm-1 at 80 °C and the highest residual IEC of 83 % after alkaline treatment for 120 h. Moreover, the assembled alkaline direct methanol fuel cell exhibits a remarkable power density of 49.3 mW cm-2 at 80 °C. This work provides a new strategy for fabricating high-performance anion exchange membranes.

[Application of vancomycin-loaded calcium sulphate in treatment of osteomyelitis].

OBJECTIVE: To investigate the role of vancomycin-loaded calcium sulphate in the treatment of osteomyelitis. METHODS: We implanted vancomycin-loaded calcium sulphate into 24 patients with traumatic osteomyelitis who were treated in our hospital from February 2008 to February 2010,and then the antibiotic concentrations in the lesions were measured.Bacterial culture results,inflammatory markers,as well as wound healing were observed.X-ray was performed in the location where the vancomycin-loaded calcium sulphate was implanted.The blood vancomycin level as well as liver and kidney functions were determined. RESULTS: The vancomycin concentration in the lesion exceeded the effective therapeutic concentrations and the minimum inhibitory concentration,while the blood concentration was low.The liver and renal function remained normal.The safety profile was good,and the cure rate of osteomyelitis reached 100%. CONCLUSIONS: The vancomycin-loaded calcium sulphate can release high-concentration vancomycin in the diseased sites without causing high blood concentration.Also,it can guide the regeneration of bones.Therefore,it is effective and safe in treating osteomyelitis.

Elevated pCO2 alleviates the toxic effects of polystyrene nanoparticles on the marine microalga Nannochloropsis oceanica.

Concerns about the environmental effects of nanoplastics on marine ecosystems are increasing. Ocean acidification (OA) has also become a global environmental problem. Plastic pollution occurs concomitantly with anthropogenic climate stressors such as OA. However, the combined effects of NP and OA on marine phytoplankton are still not well understood. Therefore, we have investigated the behavior of ammonia (NH2) polystyrene nanoparticles (PS NP) in f/2 medium under 1000 µatm pCO2 and discussed the toxicity of PS NP (100 nm; 0.5 and 1.5 mg/L) on Nannochloropsis oceanica under long and short-term acidification (LA and SA; pCO2 ~ 1000 µatm). We observed PS NP suspended in pCO2 1000 µatm f/2 medium aggregated to a size greater than nanoscale (1339.00 ± 76.10 nm). In addition, we found that PS NP significantly inhibited the growth of N. oceanica at two concentrations, which also produced oxidative stress. Whereas, the growth of algal cells under the coupling of acidification and PS NP was significantly better than that of single PS NP exposure. This indicated that acidification significantly alleviated the toxic effects of PS NP on N. oceanica, and long-term acidification can even promote the growth of N. oceanica under low-density NP. To further understand the mechanism, we analyzed a comparative transcriptome. The results showed that PS NP exposure inhibited the expression of genes involved in the TCA cycle. The acidification was possibly reflected in ribosomes and corresponding processes, which alleviated the negative effects of PS NP on N. oceanica by promoting the synthesis of related enzymes and proteins. This study provided a theoretical basis for assessing the damage of NP to marine phytoplankton under OA. We propose that future studies evaluating the toxicology of NP to marine ecology should consider the changing ocean climate.

Reproductive toxicity and cross-generational effect of polyethylene microplastics in Paramisgurnus dabryanus.

Pollution of microplastics (MPs) has become a global environmental issue due to the difficulty in its degradation and may cause unexpected ecological effects. Nevertheless, little is known about the potential effects of MPs on reproduction toxicity in aquatic species. In this study, adult loach (Paramisgurnus dabryanus, F0 generation) were exposed to two concentrations (1 and 10 mg/L) of polyethylene MPs (PE-MPs) for 15 or 30 days, and the toxic effects in parental loach and the offspring (F1 generation) were examined. Our results showed that PE-MPs exposure could change the indicators content of antioxidant system in the brain, liver, and gonad. PE-MPs can accumulate in the gonads, disrupt the transcription of HPG-axis related genes, alter sex hormone levels, increase cell apoptosis and gonadal pathological lesions, lead to the damage of biological characteristics of semen, and affect the reproduction in F0 generation. PE-MPs remaining in the parental gonads can be transferred to the F1 generation embryos and accumulated on the embryonic chorionic membrane, increasing mortality and malformation rates, accelerating hatching time, and decreasing hatching rate and body length. These results suggest that PE-MPs leads to a potential adverse influence on reproduction and serious impacts on population sustainability. This work provides a new perspective into the effects of MPs on reproductive damage and cross-generational effects in teleost fish, which have implications in fields of freshwater ecology and environmental toxicology.

Optical and Molecular Signatures of Dissolved Organic Matter Reflect Anthropogenic Influence in a Coastal River, Northeast China.

Sources and molecular composition of dissolved organic matter (DOM) in coastal rivers have been tightly linked with its reactivity and fate, thus influencing element and nutrient cycling. The DOM in coastal rivers is usually sourced from both terrestrial and marine inputs, with further complication by anthropogenic activities, which is less understood in coastal rivers located near populated industrial regions. In this study, DOM in a typical anthropogenically influenced coastal river, Daliao River, was analyzed for optical analyses and for molecular composition via Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to give a better scope of composition and sources of DOM. The DOM was enriched in autochthonous and anthropogenic inputs at upstream sites according to high chlorophyll a concentrations, strong protein-like fluorescence, and nonoxygen heteroatomic CHOS formulae (19-24% by relative peak intensity) detected by FT-ICR MS analysis. A series of surfactant-like formulae, indicative of wastewater inputs, were identified and showed a decreasing trend from upstream to the river mouth. Compared with large world rivers, the DOM of Daliao River is characterized by higher abundances of heteroatomic (excluding O) formulae and molecular lability, which is likely caused by strong autochthonous and anthropogenic inputs. In general, we demonstrate that in addition to optical properties, the molecular composition can assess the specific anthropogenic imprints and molecular lability of DOM, which is essential for constraining sources and identifying processes during the transit of DOM from the river to estuary with increasing urbanization and industrialization.

Effects of Paclitaxel-conjugated N-Succinyl-Hydroxyethyl Chitosan Film for Proliferative Cholangitis in Rabbit Biliary Stricture Model.

BACKGROUND: Paclitaxel (PTX) could inhibit the growth of fibroblasts, which occurs in proliferative cholangitis and leads to biliary stricture. However, its use has been limited due to poor bioavailability and local administration for short time. This study designed and synthesized a new PTX-conjugated chitosan film (N-succinyl-hydroxyethyl chitosan containing PTX [PTX-SHEC]) and evaluated its safety and efficiency using in vivo and in vitro experiments. METHODS:: The SHEC conjugated with PTX was confirmed by nuclear magnetic resonance (NMR) and Fourier-transform infrared spectroscopy (FT-IR) measurements. Drug releases in vitro and in vivo were determined using high-performance liquid chromatography. Cell viability in vitro was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. Rabbit biliary stricture model was constructed. All rabbits randomly divided into five groups (n = 8 in each group): the sham-operated rabbits were used as control (Group A), Groups B received laparotomies and suture, Group C received laparotomies and covered SHEC suture without the PTX coating, Group D received laparotomies and covered PTX-SHEC suture, and Group E received laparotomies and 1000 µmol/L PTX administration. Liver function tests and residual dosage of PTX from each group were measured by enzyme-linked immunosorbent assay. Histological data and α-smooth muscle actin (SMA) immunohistochemical staining of common bile duct were examined. RESULTS:: NMR and FT-IR indicated that PTX was successfully introduced, based on the appearance of signals at 7.41-7.99 ppm, 1.50 ppm, and 1.03 ppm, due to the presence of aromatic protons, methylene protons, and methyl protons of PTX, respectively. No bile leak was observed. The PTX-conjugated film could slowly release PTX for 4 weeks (8.89 ± 0.03 µg at day 30). The in vitro cell viability test revealed significantly different levels of toxicity between films with and without PTX (111.7 ± 4.0% vs. 68.1 ± 6.0%, P < 0.001), whereas no statistically significant difference was observed among the three sets of PTX-contained films (67.7 ± 5.4%, 67.2 ± 3.4%, and 59.1 ± 6.0%, P > 0.05). Histological examinations revealed that after 28 days of implantment, Groups D and E (but not Group C) had less granulation tissue and glandular hyperplasia in the site of biliary duct injury than Group B. The pattern was more obvious in Group D than Group E. Less α-SMA-positive cells were found in tissue from Groups D and E. Comparing with Group E, the liver function was improved significantly in Group D, including total bilirubin (2.69 ± 1.03 µmol/L vs. 0.81 ± 0.54 µmol/L, P = 0.014), alanine aminotransferase (87.13 ± 17.51 U/L vs. 42.12 ± 15.76 U/L, P = 0.012), and alkaline phosphatase (60.61 ± 12.31 U/L vs. 40.59 ± 8.78 U/L, P < 0.001). CONCLUSIONS: PTX-SHEC film effectively inhibites the myofibroblast proliferation and extracellular matrix over-deposition during the healing process of biliary reconstruction. This original film might offer a new way for reducing the occurrence of the benign biliary stricture.

Esophageal foreign bodies in adults with different durations of time from ingestion to effective treatment.

Objective This study was performed to identify the differences in clinical characteristics, operative methods, complications, and postoperative hospitalization stays for adults with esophageal foreign bodies with different durations of time from ingestion to effective treatment. Methods We retrospectively reviewed the medical records of 221 patients with a diagnosis of a foreign body in the esophagus, confirmed by rigid esophagoscopy, flexible esophagoscopy, or surgery. The differences between the two groups (Group A, ≤24 hours from ingestion to effective treatment; Group B, >24 hours from ingestion to effective treatment) were analyzed. Results Sharp foreign bodies comprised the majority of objects in the two groups, including jujube pits, bones (excluding fish bones), fish bones, dentures, and seafood shells. Foreign bodies located in the upper esophagus were more commonly observed in Group A than B. Significant differences were observed in the complication rate and length of postoperative hospitalization stays. Adults with esophageal foreign bodies had a high complication rate. Conclusions Rigid esophagoscopy can be used to remove sharp and bulky foreign bodies if more effective methods are unavailable. Effective treatment within 24 hours resulted in fewer complications and shorter postoperative hospitalization stays.

[Mid and long-term clinical effects of percutaneous kyphoplasty with two methods for vertebral fragility fracture in the elderly].

OBJECTIVE: To evaluate the middle-long-term clinical effects of unilateral and bilateral percutaneous kyphoplasty(PKP) for vertebral fragility fracture in the elderly. METHODS: The clinical data in elderly patients with vertebral fragility fracture treated by unilateral and bilateral PKP between January 2008 and January 2010 was retrospective analyzed. According to a unified criteria to divided into two groups for 104 patients(44 males and 60 females), of them, 50 cases were divided in unilateral group using unilateral pedicle surgical approach for PKP and 54 cases were in bilateral group using bilateral pedicle approach. VAS score, Cobb angle, and the height of anterior and posterior vertebral body were respectively analyzed peroperatively and at 3 d, 3 months, 1 year, 3 years postoperatively and final follow-up. Clinical effects and safety were assessed in two groups. RESULTS: All the operations were successful. Operative time and bone cement injection volume in unilateral group were less than those of bilateral group(P<0.05). Postoperative VAS scores, Cobb angle, and the height of anterior and posterior vertebral body were obviously improved in two groups(P<0.05), and there was no significant difference between two groups(P>0.05). Bone cement leakage occurred in 12 cases(11.5%), recurrent fracture of vertebral body occurred in 5 cases(4.8%), cerebrospinal leak occurred in 2 cases(1.9%), and nerve root irritation occurred in 3 cases(2.9%). The above complications were transient and released after symptomatic treament. CONCLUSIONS: Middle-long-term clinical effects of unilateral and bilateral percutaneous kyphoplasty for vertebral fragility fracture are safe and satisfactory, and may be extended as a minimally invasive method. Unilateral approach for PKP has advantages of short operation time, relative less trauma, thus is a more ideal method.

[Sleep architecture changes in children with adenoidal hypertrophy].

OBJECTIVE: Adenoidal hypertrophy in children is associated with obstructive manifestations like mouth breathing, snoring, night cough. However, the sleep architecture is poorly defined in children with AH, which is this studies for. METHOD: A computer-assistant diagnostic system was used for polysomnography (PSG) recording. Sleep was scored manually according to the standard set by Rechtschaffen. 47 children with adenotonsillar hypertrophy (AH) were defined by PSG and compared with normal children PSG results. RESULT: (1) Compared with normal children, AH group had increased stage I: (15. 4 +/- 9.3)% vs (7.9 +/- 6.8)% (P < 0.01) and decreased stage II: (41.8 +/- 9.7)% vs (46.7 +/- 7.6)% (P < 0.01); increased Delta (26.2 +/- 10.6)% vs (23.3 +/- 8.7) % (P > 0.05); obviously decreased in REM: (7.7 +/- 4.9)% vs (27.3 +/- 5.6)% (P < 0.01); NREM (83.33%) was increasingly; (2) AH group had increased Arousal Index(ARI) 32.8 +/- 26.03 vs 18.3 +/- 12.2 (P < 0.05); (3) The latent period of REM was (157.1 +/- 71.4) min and about two times long as normal children. CONCLUSION: Sleep architecture is abnormal in children with AH. Frequent electroencephalogram arousals from sleep may result in significant sleep fragmentation,but the deep sleep is sufficient. Further studies are needed to determine whether abnormalities in sleep architecture contribute to quality of life.

Sleep architecture in children with adenoidal hypertrophy.

AIM: Adenoidal hypertrophy (AH) in children is associated with obstructive manifestations like mouth breathing, snoring. Unfortunately, little is known regarding sleep architecture of AH in children. The purpose of this study was therefore undertaken to investigate the polysomnographic variables in children with AH. METHOD: 47 children with AH and 11 controls underwent nocturnal polysomnography. Sleep was scored manually according to the standard set by Rechtschaffen. RESULTS: In AH, stage 1 sleep percentage and rapid eye movement (REM) latency were increased significantly, while the sleep percentage of stage 2 and REM was decreased remarkably compared with that of controls. Arousal index in AH was much more higher than that in controls. Arousal index in REM sleep was higher than that in non-rapid eye movement (NREM) sleep in AH, but the number of arousals in REM sleep was lower than that in NREM sleep. Hypopnea events were the most common type of respiratory events, followed by obstructive events in AH and controls. Apnea/hypopnea index in AH was higher in comparison to controls. No significant difference was found between the children with AH and controls in SaO(2) nadir (%) and base mean SaO(2) (%). Apnea/hypopnea index was related to hypopnea arousal in REM sleep and hypoxemia arousal in NREM sleep. CONCLUSION: AH is predominantly characterised by a hypopnea with little obstruction in children. Our results clearly and for the first time demonstrated that sleep architecture was abnormal in children with AH. We therefore speculate that hypopnea arousal in REM sleep and hypoxemia arousal in NREM sleep may play an important role in the course of respiratory disturbance.