Unique modulation effects on the performance of graphene-based ammonia sensors via ultrathin bimetallic Au/Pt layers and gate voltages.

Gas sensors with superior comprehensive performance at room temperature (RT) are always desired. Here, Au, Pt and Pt/Au-decorated graphene-based field effect transistor (FET) sensors for ammonia (denoted as Au/Gr, Pt/Gr and Pt/Au/Gr, respectively) are designed and fabricated. All these devices exhibited far better RT sensing performances for ammonia compared with graphene devices. Applying positive back gate voltages can further enhance their RT performance in which the Pt/Au/Gr devices show superior RT comprehensive performance such as a response of -16.2%, a recovery time of 4.6 min, and especially a much reduced response time of 54 s for 200 ppm NH3 with a detection limit of 103 ppb at a gate voltage of +60 V, and can be potentially tailored for further performance improvement by controlling the ratios of Pt and Au. The dependences of their performance on the gate voltage except for the response time could be reasonably explained by theoretical calculations in terms of the changes of the total density of states near the Fermi level, adsorption energies, transferred charges and adsorption distances. This study provides an effective solution for performance improvement of FET-based sensors via synergistic effects of ultrathin-layer multiple-metallic decoration and gate voltage, which would promote the exploration of novel sensors.

Cu/graphene interdigitated electrodes with various copper thicknesses for UV-illumination-enhanced gas sensors at room temperature.

Effective detection of NO2 and NH3 gases at room temperature (RT) is critical for environmental monitoring and protection. Here, graphene-based gas sensors (Cu/Gr device) of single layer graphene decorated by 6, 8 and 10 nm thick Cu layers with graphene instead of conventional metal as interdigital electrodes are designed and fabricated. The RT performance for both NO2 and NH3 detection can be greatly enhanced by UV light illumination which is closely related to the thickness of Cu layers in which the device with 8 nm thickness (8 nm Cu/Gr device) exhibits the best performances. Analysis of XPS reveals that Cu is partly oxidized to Cu+ and Cu2+ for 6 nm with extra Cuδ+ (1 < δ < 2) for 8 and 10 nm. The contents and distributions of copper oxides and copper in Cu layers influence the catalytic effects and the heterojunction barrier and thus the performances. The RT responses of -30.9% and -8.1% for 5 and 0.3 ppm NO2, and of +29.1% and +5.9% for 105 and 10 ppm NH3 are achieved for the 8 nm Cu/Gr device, respectively. The limits of detection (LODs) for NO2 and NH3 are 12 ppb and 17 ppb, respectively. The sensing mechanisms are discussed in terms of density functional theory (DFT) calculations and energy band diagrams. The study demonstrates an effective solution of improving the device performance by modifying the device configuration and incorporating combined oxides naturally oxidized, which provides the novel design alternatives for high performance sensors.

Computational fluid dynamics approaches to drag and wake of a long-line mussel dropper under tidal current.

Hydrodynamic effects of mussel farms have attracted increased research attentions in recent years. The understanding of the hydrodynamic impacts is essential for predicting the sustainability of mussel farms. A large mussel farm includes thousands of mussel droppers, and the combined drag on the mussel droppers is sufficient to possibly affect the longevity of the entire long-lines. This article intends to study the drag and wake of an individual long-line mussel dropper using computational fluid dynamics approaches. Two equivalent rough cylinders, namely, Curved-Model and Sharp-Model, have been utilized to simulate the mussel dropper, and each rough cylinder is assigned with surface roughness. The porosity is not considered in this article due to its complexity from inhalant and exhalant of mussels. Two-dimensional laminar simulations are conducted at Reynolds number from 10 to 200, and three-dimensional large eddy simulations are conducted at subcritical Reynolds number ranging from 3900 to 105. The results show that larger drag coefficients and Strouhal numbers are attributed to surface roughness and sharp crowns on the rough cylinder. The obtained drag coefficient ranges from 1.1 to 1.2 with respect to the diameter of the mussel dropper and the peak value of the tidal velocities. Wakes behind rough cylinders fluctuate more actively compared to those of smooth cylinders. This research work provides new insight for further investigations on hydrodynamic interactions between fluid and mussel droppers.

Odds ratio of programmed cell death-1 or ligand 1 inhibitor-related endocrine dysfunction in patients with lung cancer: A systematic review and meta-analysis.

PURPOSE: We designed the study to investigate the incidence risk of Programmed Cell Death-1 (PD-1) or Ligand 1 (PD-L1) inhibitor-related endocrine dysfunction in patients with lung cancer. METHOD: All the data were collected by 1 primary reviewer and then independently reviewed by 2 secondary reviewers according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISM) guidelines. Incidence risk of all-grade and grade 3-5 PD-1/PD-L1 inhibitors related endocrine dysfunction in patients with lung cancer were taken into account. RESULTS: Overall, 12 clinical trials comprising 6108 patients were identified in this systematic review and meta-analysis. The incidence risk of hypothyroidism, hyperthyroidism and adrenal insufficiency was higher in NSCLC patients receiving combination treatments. The incidence rate of all-grade of hypothyroidism was lower in PD-1/PD-L1 inhibitor subgroup compared to chemotherapy (OR = 22.62, 95%CI:9.79-52.25), while the similar result was seen in another treatment regimen (PD-1 + platinum-based chemotherapy vs platinum-based chemotherapy) (OR = 2.93, 95%CI: [2.08, 4.11). The different result can be seen in the group related to the other treatment regimen (1PD-1/PD-L1 inhibitor vs 2 PD-1/PD-L1 inhibitors) (OR = 0.40, 95%CI:0.21-0.76). All the results of the above analysis were considered to be statistical significant. Similar result could also be seen in meta-analysis related to hyperthyroidism and adrenal insufficiency. CONCLUSION: The incidence risk of endocrine dysfunctions, including hypothyroidism, hyperthyroidism and adrenal insufficiency, were higher for PD-1/PD-L1 inhibitors group.

Methotrexate, doxorubicin, and cisplatinum regimen is still the preferred option for osteosarcoma chemotherapy: A meta-analysis and clinical observation.

BACKGROUND: We designed the study to investigate whether methotrexate, doxorubicin, and cisplatinum (MAP) chemotherapy strategy was still the preferred option for the survival of osteosarcoma patients. METHOD: We collected some trials of osteosarcoma to make a meta-analysis first. Then, we retrospectively collected data from 115 patients with osteosarcoma and performed further analysis to verify the impact of MAP regimen on the survival of patients. RESULTS: Seven studies including 3433 participants met the preliminary inclusion criteria. Meta-analysis of the 3-year disease-free survival (odds ratio [OR] = 1.06, 95% confidence interval [CI]: 0.88-1.28; P = .52) and overall survival (OR = 1.21, 95% CI: 0.70-2.11; P = .54), 5-year disease-free survival (OR = 1.07, 95% CI: 0.87-1.30; P = .54) and overall survival (OR = 0.86, 95% CI: 0.65-1.12; P = .26), and mortality rate (OR = 0.90, 95% CI: 0.70-1.17; P = .44), showed no statistically significant differences. The most common grade 3/4 adverse events were neutropenia (498 [85.9%] patients in MAP vs 533 [93.3%] in MAP plus ifosfamide and etoposide, or other adjuvant therapy drugs [MAP]). MAP was associated with less frequent toxicities than MAP group with statistical significance in thrombocytopenia, febrile neutropenia, anemia, and hypophosphatemia. The same phenomenon could also be seen in the analysis of clinical data. CONCLUSION: MAP regimen remains the preferred option for osteosarcoma chemotherapy.

Incidence risk of PD-1/PD-L1 related diarrhea in non-small cell lung cancer (NSCLC) patients: a systematic review and meta-analysis.

Purpose: We designed the study to illustrate the OR of programmed cell death-1 (PD-1) or ligand 1 (PD-L1) inhibitor-related diarrhea in patients with non-small cell lung cancer. Method: This systematic review and meta-analysis were put into practice according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Incidence of all grades for PD-1/PD-L1 inhibitor-related diarrhea in NSCLC was taken into account. Results: After screening and eligibility assessment of 57 articles, a total of 12 clinical trials involving 6,659 participants were collected for the final meta-analysis. The incidence risk of diarrhea for all grades was lower in PD-1 inhibitor monotherapy compared to monochemotherapy of docetaxel (OR=0.31, 95% CI [0.24, 0.41]; I2=0%, Z=8.23 (p<0.00001)), while a similar result could also be seen in PD-L1 inhibitor monotherapy group (OR=0.41, 95% CI [0.27, 0.64]; I2=59%, Z=3.92 [p<0.00001]). The opposite result can be seen when PD-1/PD-L1 inhibitor combined chemotherapy was compared to chemotherapy alone (OR=1.51, 95% CI [1.22, 1.87]; I2=0%, Z=3.77 [p<0.00001]). Similar incidence trend could also be seen in the meta-analysis of diarrhea for grade 1-2 and grade 3-5. Conclusion: The incidence risk of diarrhea associated with PD-1/-PD-L1 inhibitor monotherapy was significantly lower than that of docetaxel monotherapy group. However it was higher in PD-1/PD-L1 inhibitor combined with chemotherapy group compared with the chemotherapy alone group.

Carbon-decorated Li4Ti5O12/rutile TiO2 mesoporous microspheres with nanostructures as high-performance anode materials in lithium-ion batteries.

Li4Ti5O12/rutile TiO2 (LTO-RT) composites with Li/Ti molar ratios of 3:5, 4:5 and 4.5:5 have been successfully synthesized with TiO2 microspheres as a precursor. Furthermore, C-coated LTO-RT mesoporous microspheres with a molar ratio of 4:5 (C/4-5-LTO-RT) have been prepared based on the LTO-RT composite through a hydrothermal method and high temperature calcination. After various characterizations, it is found that carbon plays a pivotal role in retaining the porous nanostructure of the original as-prepared TiO2 precursor in the overall process. Substantially, C/4-5-LTO-RT still shows a high specific surface area of 63.70 m(2) g(-1) even after high temperature treatment at 800 °C. Since the porous nanostructure offers open and direct channels for the diffusion of Li ions and electrons and carbon decoration also efficiently improves the electrical conductivity, the sample of C/4-5-LTO-RT shows an enhanced electrochemical performance. In addition, the presence of nanosized rutile TiO2 in C/4-5-LTO-RT has an important contribution to the high electrochemical performance, as does the fast lithium ion diffusion along the [001] direction.

The toxic influence of paraquat on hippocampus of mice: involvement of oxidative stress.

Environmental paraquat (PQ) exposure has been suggested to be a potential risk factor for neurodegenerative disorders such as Parkinson's disease (PD). The hippocampus plays an important role in the learning and memory abilities of the brain. This study aims to demonstrate the effect and mechanism of paraquat toxicity on the hippocampus of mice. Kunming mice were randomly divided into four groups (one control and three treatment groups) and the dosage levels were defined as 0, 0.89, 2.67 and 8mg/kg body weight. Paraquat was given orally, once a day and for 28 consecutive days. After treatment with paraquat, the hippocampus cells were found to be irregular and the cytoplasm was found to be condensed. The nissl bodies were reduced and apoptotic or necrotic neuron was observed. Morris water maze tests showed that the response latency increased significantly in animals that were administered paraquat. The level of malondialdehyde (MDA) and generation of reactive oxygen species (ROS) in the hippocampus of mice increased significantly. The activities of total superoxide dismutase (SOD) in the hippocampus of mice decreased significantly after treatment with paraquat. An analysis of the energy metabolism of hippocampus showed that the concentration of adenosine-triphosphate (ATP) decreased significantly in the hippocampus after treatment with paraquat, which implied that the energy synthesis of mitochondria with hippocampal neurocytes declined. The level of 8-OHdG in mitochondrial DNA (mtDNA) increased significantly after treatment with paraquat, which indicated that the oxidative damage of mtDNA increased. This suggests that paraquat had a toxic influence on the hippocampus of mice, and that the mechanism of toxicity might be associated with the mitochondrial injury of hippocampal neurocytes induced by oxidative stress.