Carbon-supported PdNi catalysts for the ethanol oxidation reaction in alkaline direct ethanol fuel cells are successfully synthesized by the simultaneous reduction method using NaBH
4 as reductant. ...X-ray diffraction characterization confirms the formation of the face-centered cubic crystalline Pd and Ni(OH)
2 on the carbon powder for the PdNi/C catalysts. Transmission electron microscopy images show that the metal particles are well-dispersed on the carbon powder, while energy-dispersive X-ray spectrometer results indicate the uniform distribution of Ni around Pd. X-ray photoelectron spectroscopy analyses reveal the chemical states of Ni, including metallic Ni, NiO, Ni(OH)
2 and NiOOH. Cyclic voltammetry and chronopotentiometry tests demonstrate that the Pd
2Ni
3/C catalyst exhibits higher activity and stability for the ethanol oxidation reaction in an alkaline medium than does the Pd/C catalyst. Fuel cell performance tests show that the application of Pd
2Ni
3/C as the anode catalyst of an alkaline direct ethanol fuel cell with an anion-exchange membrane can yield a maximum power density of 90
mW
cm
−2 at 60
°C.
MicroRNAs are a class of small, non‐coding RNAs that can negatively regulate protein‐coding genes, and are associated with almost all known physiological and pathological processes, especially ...cancer. The number of studies documenting miRNA expression patterns in malignancy continues to expand rapidly, with continuously gained critical information regarding how aberrantly expressed miRNAs may contribute to carcinogenesis. miRNAs can influence cancer pathogenesis, playing a potential role as either oncogenes or tumour suppressors. Recently, several miRNAs have been reported to exert different regulatory functions in oesophageal cancer – the carcinoma typically arising from the epithelial lining of the oesophagus. These miRNAs also have potential clinical applications towards developing biomarkers or targets for possible use in diagnosis or therapy in oesophageal cancer. In this review, we have summarized the two (oncogenic or tumour suppressive) roles of miRNAs here, and their applications as potential biomarkers or therapeutic targets, which may illuminate future treatment for oesophageal cancer.
Cancer patients are regarded as a highly vulnerable group in the current Coronavirus Disease 2019 (COVID-19) pandemic. To date, the clinical characteristics of COVID-19-infected cancer patients ...remain largely unknown.
In this retrospective cohort study, we included cancer patients with laboratory-confirmed COVID-19 from three designated hospitals in Wuhan, China. Clinical data were collected from medical records from 13 January 2020 to 26 February 2020. Univariate and multivariate analyses were carried out to assess the risk factors associated with severe events defined as a condition requiring admission to an intensive care unit, the use of mechanical ventilation, or death.
A total of 28 COVID-19-infected cancer patients were included; 17 (60.7%) patients were male. Median (interquartile range) age was 65.0 (56.0–70.0) years. Lung cancer was the most frequent cancer type (n = 7; 25.0%). Eight (28.6%) patients were suspected to have hospital-associated transmission. The following clinical features were shown in our cohort: fever (n = 23, 82.1%), dry cough (n = 22, 81%), and dyspnoea (n = 14, 50.0%), along with lymphopaenia (n = 23, 82.1%), high level of high-sensitivity C-reactive protein (n = 23, 82.1%), anaemia (n = 21, 75.0%), and hypoproteinaemia (n = 25, 89.3%). The common chest computed tomography (CT) findings were ground-glass opacity (n = 21, 75.0%) and patchy consolidation (n = 13, 46.3%). A total of 15 (53.6%) patients had severe events and the mortality rate was 28.6%. If the last antitumour treatment was within 14 days, it significantly increased the risk of developing severe events hazard ratio (HR) = 4.079, 95% confidence interval (CI) 1.086–15.322, P = 0.037. Furthermore, patchy consolidation on CT on admission was associated with a higher risk of developing severe events (HR = 5.438, 95% CI 1.498–19.748, P = 0.010).
Cancer patients show deteriorating conditions and poor outcomes from the COVID-19 infection. It is recommended that cancer patients receiving antitumour treatments should have vigorous screening for COVID-19 infection and should avoid treatments causing immunosuppression or have their dosages decreased in case of COVID-19 coinfection.
•We retrospectively studied clinical features of 28 severe Coronavirus Disease 2019 (COVID-19)-infected cancer patients from three hospitals in Wuhan, China.•We analysed risk factors associated with occurrence of admission to an intensive care unit, usage of mechanical ventilation, or death.•COVID-19-infected cancer patients presented poor outcomes with high occurrence of clinically severe event and mortality.•Antitumour treatment within 14 days of COVID-19 diagnosis increased the risk of developing severe events.
Molecular-scale manipulation of electronic and ionic charge accumulation in materials is the backbone of electrochemical energy storage
. Layered van der Waals (vdW) crystals are a diverse family of ...materials into which mobile ions can electrochemically intercalate into the interlamellar gaps of the host atomic lattice
. The structural diversity of such materials enables the interfacial properties of composites to be optimized to improve ion intercalation for energy storage and electronic devices
. However, the ability of heterolayers to modify intercalation reactions, and their role at the atomic level, are yet to be elucidated. Here we demonstrate the electrointercalation of lithium at the level of individual atomic interfaces of dissimilar vdW layers. Electrochemical devices based on vdW heterostructures
of stacked hexagonal boron nitride, graphene and molybdenum dichalcogenide (MoX
; X = S, Se) layers are constructed. We use transmission electron microscopy, in situ magnetoresistance and optical spectroscopy techniques, as well as low-temperature quantum magneto-oscillation measurements and ab initio calculations, to resolve the intermediate stages of lithium intercalation at heterointerfaces. The formation of vdW heterointerfaces between graphene and MoX
results in a more than tenfold greater accumulation of charge in MoX
when compared to MoX
/MoX
homointerfaces, while enforcing a more negative intercalation potential than that of bulk MoX
by at least 0.5 V. Beyond energy storage, our combined experimental and computational methodology for manipulating and characterizing the electrochemical behaviour of layered systems opens new pathways to control the charge density in two-dimensional electronic and optoelectronic devices.
A large change in albedo has a significant effect on glacier ablation. Atmospheric aerosols – e.g. black carbon (BC) and dust – can reduce the albedo of glaciers and thus contribute to their melting. ...In this study, two main themes were explored: (1) the decrease in albedo of the Zhadang glacier on Mt. Nyainqentanglha between 2001 and 2012, as observed by the Moderate Resolution Imaging Spectroradiometer (MODIS) on-board the Terra satellite, and the correlation of this albedo with mass balance; and (2) the concentrations of BC and dust in the glacier measured during 2012, and the associated impacts of these impurities on albedo and radiative forcings (RF). The average albedo of the Zhadang glacier from the MODIS increased with the altitude and fluctuated but had a decreasing trend (−0.003 a−1) during the period 2001–2012, with the highest (0.722) in 2003 and the lowest (0.597) in 2009 and 2010. The mass balance of the glacier has a positively significant correlation with its surface albedo derived from MODIS. Snow samples were collected on the Zhadang glacier to measure the BC and dust in the summer of 2012. The impacts of BC and dust on albedo reduction in different melting conditions were identified with the SNow ICe Aerosol Radiative (SNICAR) model initiated by in situ observation data. The sensitivity analysis showed that BC was a major factor in albedo reduction when the glacier was covered by newly fallen snow. Nevertheless, the contribution of dust to albedo reduction can reach as high as 56%, much exceeding that of BC (28%), when the glacier experiences strong surficial melting and its surface is almost bare ice. The average RF caused by dust could increase from 1.1 to 8.6 W m−2, exceeding the RF caused by BC after snow was deposited and surface melting occurred in the Zhadang glacier. This implies that it may be dust that primarily dominates the melting of some glaciers in the inner Tibetan Plateau during melting seasons, rather than BC.
A general feature of unconventional superconductors is the existence of a superconducting dome in the phase diagram. Here we report a series of discrete superconducting phases in the simplest ...iron-based superconductor, FeSe thin flakes, by continuously tuning the carrier concentration through the intercalation of Li and Na ions with a solid ionic gating technique. Such discrete superconducting phases are robust against the substitution of 20% S for Se, but they are vulnerable to the substitution of 2% Cu for Fe, highlighting the importance of the iron site being intact. The superconducting phase diagram for FeSe derivatives is given, which is distinct from that of other unconventional superconductors.
One favorable situation for spins to enter the long-sought quantum spin liquid (QSL) state is when they sit on a kagome lattice. No consensus has been reached in theory regarding the true ground ...state of this promising platform. The experimental efforts, relying mostly on one archetypal material ZnCu_{3}(OH)_{6}Cl_{2}, have also led to diverse possibilities. Apart from subtle interactions in the Hamiltonian, there is the additional degree of complexity associated with disorder in the real material ZnCu_{3}(OH)_{6}Cl_{2} that haunts most experimental probes. Here we resort to heat transport measurement, a cleaner probe in which instead of contributing directly, the disorder only impacts the signal from the kagome spins. For ZnCu_{3}(OH)_{6}Cl_{2}, we observed no contribution by any spin excitation nor obvious field-induced change to the thermal conductivity. These results impose strong constraints on various scenarios about the ground state of this kagome compound: while certain quantum paramagnetic states other than a QSL may serve as natural candidates, a QSL state, gapless or gapped, must be dramatically modified by the disorder so that the kagome spin excitations are localized.
To investigate the clinical and coagulation characteristics of the critical Coronavirus disease 2019 (COVID-19) patients with acro-ischemia in the intensive care unit (ICU).
The retrospective study ...included 7 critical COVID-19 patients with acro-ischemia in a single center in Wuhan, from Feb 4 to Feb 15, 2020. The clinical and laboratory data before and during the ICU stay were analyzed.
The median age of 7 patients was 59 years and 4 of them were men. 3 of them were associated with underlying comorbidities. Fever, cough, dyspnea and diarrhea were common clinical symptoms. All patients had acro-ischemia presentations including finger/toe cyanosis, skin bulla and dry gangrene. D-dimer, fibrinogen and fibrinogen degradation product (FDP) were significantly elevated in most patients. Prothrombin time (PT) were prolonged in 4 patients. D-dimer and FDP levels increased progressively when COVID-2019 exacerbated, and 4 patients were diagnosed with definite disseminated intravascular coagulation (DIC). 6 patients received low molecular weight heparin (LMWH) treatment, after which their D-dimer and FDP decreased, but there was no significant improvement in clinical symptoms. 5 patients died finally and the median time from acro-ischemia to death was 12 days.
The existence of hypercoagulation status in critical COVID-2019 patients should be monitored closely, and anticoagulation therapy can be considered in selected patients. More clinical data is needed to investigate the role of anticoagulation in COVID-2019 treatment.
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