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.
A new kind of functional surfaces with particular characteristics, i.e., superhydrophobic surfaces, has recently been developed and applied in many fields, such as airplane, wind turbine, electric ...power line, photovoltaic cell, heat exchanges, ice slurry generator, and so on. The freezing delay and ice-accumulation avoiding on the surfaces are important to keep stable working condition for these devices. The frictional pressure loss of flow through the tubes or channels with superhydrophobic surfaces is much smaller than that through those without superhydrophobic surfaces. Both the boiling and condensation heat transfer performances on superhydrophobic surfaces can be enhanced. The superhydrophobic surfaces have potential applications and are worthy further investigations. We provide here a review of the fabrications, characterization and the emerging energy-related applications of superhydrophobic surfaces on the basis of the recent progresses of the research and development in this field. The fabrication of superhydrophobic surface, in particular a recently developed SLIPS (slippery liquid-infused porous surface), is summarized. The focuses are placed on the particular characteristics of superhydrophobic surfaces and their applications in energy-related fields. The further research topics are also clarified to promote the future applications.
•Recent progress on superhydrophobic surfaces is reviewed.•The superhydrophobic surfaces are gradually used in the energy-related applications.•Application of superhydrophobic surfaces can enhance the system performance.•The further research topics are proposed.
General relationship between strength and hardness Zhang, P.; Li, S.X.; Zhang, Z.F.
Materials science & engineering. A, Structural materials : properties, microstructure and processing,
11/2011, Letnik:
529
Journal Article
Recenzirano
► The hardness is not an intrinsic property but reflects the hardening state in CG. ► The ratio of hardness to strength can also be reflected by indentation morphology. ► The ratio of hardness to ...strength increases with increasing parameter
α. ►
H
V
=
3
σ
UTS
is valid for materials with relatively high strength and better toughness.
Both hardness and strength are the important properties of materials, and they often obey the three times empirical relationship in work-hardened metals and some bulk metallic glasses (BMGs). But the relationships between strength and hardness are quite different for those coarse-grained (CG) and ultrafine-grained materials, brittle BMGs and ceramics. In the present work, some Cu alloys with different microstructures, Zr-, Co-based BMGs and Al
2O
3 were employed to analyze the general relationship between hardness and strength. Several different relationships could be gotten from the experimental results of different materials available, and three types of indentation morphologies were observed. Indentation with “sink-in” morphology always represents a state of material and one third of hardness is in the range from yield strength to ultimate tensile strength. The other two indentation morphologies induced the fully hardening of material, so hardness could represent the intrinsic mechanical property of materials. The ratios of hardness to strength are found to be affected by the piled-up behaviors and their ability of shear deformation. Combined effect of the two aspects makes hardness approximately be three times of strength in the work-hardened crystalline materials and the shearable BMGs, but higher than three times of strength in the brittle-, annealed BMGs and ceramics.
The cyclic deformation and damage behaviors of the Fe–Mn and Fe–Mn–C TRIP/TWIP steels are comprehensively studied in a wide range of strain amplitude (from 0.3% to 8.0%). It is found that with ...increasing C content, the dislocation structures change from wavy slip to planar slip after cyclic deformation. In order to evaluate the low-cycle and extremely-low-cycle fatigue (LCF and ELCF) properties, a fatigue life prediction model, Nf = (Wa/W0)β, with a hysteresis energy-based criterion is used and developed. The model reveals that the LCF and ELCF damage mechanisms can be controlled by the material's damage capacity (the intrinsic fatigue toughness W0) and its ability of transforming mechanical work into effective damage (the damage transition exponent β). From a macroscopic point of view, W0 is related to the match of strength and ductility (approximately the static toughness U), and β mainly has a negative correlation with the cyclic strain hardening exponent n′. On the micro-scale level, W0 represents the defect-accommodated ability of the materials, and β is determined by the uniformity and reversibility of plastic deformation. For the current Fe–Mn(–C) TRIP/TWIP steels with increasing C content, the cooperation between an increasing damage capacity and an incremental damage accumulation rate leads to a higher ELCF property and a lower LCF property.
The low-cycle fatigue (LCF) damage mechanisms may be controlled by the material's damage capacity and damage accumulation rate. The influences of planar slip caused by short-range order (SRO) on fatigue damage and cracking are quite different from those caused by lowering the stacking fault energy (SFE), which has its origin from the various effects on damage accumulation rate. Display omitted
Objectives
The aim of this study was to investigate the predictive factors for relapse of IgG4‐related disease (IgG4‐RD) and observe the long‐term clinical outcomes in patients with IgG4‐RD.
Methods
...We included in the present analysis 122 patients who were newly diagnosed with IgG4‐RD, treated with glucocorticoid (GC) monotherapy or GC and immunosuppressant combination therapy, and followed for at least 3 years. Clinical relapse, response and side effects were recorded.
Results
The cumulative relapse rates of patients in this study were 10.66%, 22.95% and 27.87% at 12, 24 and 36 months, respectively. Complete drug withdrawal was an independent risk factor for disease relapse. Higher serum IgG4 concentrations, involvement of more organs, higher IgG4 RI scores and elevation of eosinophils at baseline were closely associated with disease relapse. Re‐elevation of serum IgG4 concentrations and low GC maintenance dosage during the follow‐up period were significantly associated with clinical relapse. The GC dosage should be more than 6.25 mg day−1 as monotherapy during the maintenance stage; moreover, combining with immunosuppressants can reduce the GC dosage. Adding GC or immunosuppressants for patients with re‐elevation of serum IgG4 levels could prevent later disease relapse. No serious complications were noted during long‐term follow‐up.
Conclusions
The combination of GC with immunosuppressants was more effective than GC monotherapy during the steroid tapering and maintenance stages. Higher serum IgG4 levels, involvement of more organs, higher IgG4 RI scores, history of allergy, eosinophil elevation at baseline, re‐elevation of serum IgG4 levels and lower GC maintenance dosage at follow‐up might be predictive of relapse.
The extremely-low-cycle fatigue (ELCF) behaviors of pure Cu and Cu–Al alloys are comprehensively studied following the cyclic push–pull loading tests with extremely high strain amplitudes (up to ...±9.5%). Compared with the common low-cycle fatigue (LCF) region, several unique features in the ELCF regime can be noticed, including the deviations of fatigue life from the Coffin–Manson law, the non-negligible proportion occupied by the cyclic hardening stage of the whole fatigue life, special microstructures formed by cyclic loading containing deformation twins, shear bands and ultra-fine grains and the transformation of fatigue cracking modes. All these characteristics indicate the existence of special interior fatigue damage mechanisms of ELCF. To help discover the new damage mechanisms under ELCF, a model of fatigue life prediction with a hysteresis energy-based criterion is proposed. Based on the analysis of the experimental and modeling results, two intrinsic factors determining the ELCF properties were concluded: the capacity of ELCF damage, and the defusing and dispersion ability of the external mechanical work. The former can be evaluated by a parameter of the model called the intrinsic fatigue toughness W0, which is related to the microstructure evolution condition, the cyclic hardening ability, the deformation homogeneity and possibly the static toughness. The latter can be represented by the damage transition exponent β, which can be enhanced by improving the planarity, reversibility and uniformity of plastic deformation, reflecting the decline in the degree of surface damage and the dispersion of fatigue cracks. For Cu–Al alloys with increasing Al content, cooperation between an increasing damage capacity and a decreasing damage accumulation rate leads to a comprehensive improvement in the ELCF properties.
•Paraffin/metal foam composite PCMs were prepared with vacuum assistance.•The impregnation ratios showed impregnation with vacuum assistance was effective.•The thermal conductivities of the composite ...PCMs were significantly enhanced.•Porous metal foam induced slight shift of the phase change temperatures of PCMs.
The utilization of paraffin in the latent thermal energy storage (LTES) system for solar energy storage is hampered by its low thermal conductivity. Paraffin/nickel foam and paraffin/copper foam composite phase change materials (PCMs) were prepared using a vacuum impregnation method in the present study. The impregnation ratios which reflect the actual mass fraction of pure paraffin impregnated were studied comparatively for the impregnations with and without vacuum assistance. The surface porosity was obtained by employing the image processing approach. The thermal conductivities of the composite PCMs were measured by the transient plane heat source technique (TPS) as well as the steady state method, and the thermal behaviors were analyzed with a differential scanning calorimeter (DSC). It is found that the surface porosity obtained from image analysis was in the range of 90–94%, whereas the bulk porosity predicted by the mass fraction was about 97%. Compared with pure paraffin, the thermal conductivities of the composite PCMs were drastically enhanced, e.g., the thermal conductivity of the paraffin/nickel foam composite was nearly three times larger than that of pure paraffin. The presence of porous metal foam made the phase change temperatures shift slightly, e.g., the deviations of the peak melting temperatures of the paraffin/nickel foam composite and paraffin/copper foam composite with the pore size of 25PPI from those of pure paraffin were 0.55°C and 0.40°C, respectively.
We give an account of the gravitational memory effect in the presence of the exact plane wave solution of Einstein's vacuum equations. This allows an elementary but exact description of the soft ...gravitons and how their presence may be detected by observing the motion of freely falling particles. The theorem of Bondi and Pirani on caustics (for which we present a new proof) implies that the asymptotic relative velocity is constant but not zero, in contradiction with the permanent displacement claimed by Zel'dovich and Polnarev. A non-vanishing asymptotic relative velocity might be used to detect gravitational waves through the “velocity memory effect”, considered by Braginsky, Thorne, Grishchuk, and Polnarev.
A
bstract
We study the factorization relations between quasi gluon GPDs and twist-2 GPDs. The perturbative coefficient functions are obtained at one-loop level. They are free from any collinear- or ...I.R. divergences. Unlike the case of the factorization of quasi quark GPDs at one-loop, we have to add ghost contributions for the factorization of quasi gluon GPDs in order to obtain gauge-invariant results. In general, operators will be mixed beyond tree-level. Our work shows that the mixing pattern of the nonlocal operators in quasi gluon GPDs is the same as those of local operators, i.e., the nonlocal operators considered are mixed with gauge-invariant operators, BRST-variation operators and operators involving EOM operator. The factorization relations are obtained for all quasi gluon GPDs. Taking the forward limit, we also obtain the relations between quasi gluon PDFs and twist-2 PDFs.
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