A numerical method accounting for conjugate hydrogen permeation in a dense palladium (Pd) membrane tube is developed. In the method, hydrogen permeation across the membrane is treated by introducing ...a source–sink pair and a gas mixture produced from water gas shift reactions serves as the feed gas of the membrane tube. The influences of flow patterns of feed gas and sweep gas as well as their flow rates on hydrogen separation are investigated. A concentration polarization index (CPI) is also conducted to indicate the extent of polarization along the membrane surface. The predicted results suggest that counter-current modes are able to give the better performance of hydrogen separation compared to co-current modes, and hydrogen can be completely recovered if the flow rate of feed gas is low to a certain extent. However, lower flow rates of feed gas and sweep gas will trigger serious concentration polarization. With counter-current modes, the feed gas sent into the membrane tube from the lumen side or the shell side is flexible. The optimum Reynolds number of sweep gas in accordance with the Reynolds number of feed gas is correlated by an arctangent function. This provides a useful reference for the operation of hydrogen separation by controlling sweep gas.
► A numerical method accounting for conjugate hydrogen permeation is developed. ► Hydrogen permeation is treated by introducing a source–sink pair. ► A gas mixture produced from water gas shift reactions serves as the feed gas. ► A concentration polarization index is conducted to indicate the extent of polarization. ► The optimum Reynolds number of sweep gas is correlated by an arctangent function.
Cancer cachexia is a highly prevalent condition associated with poor quality of life and reduced survival
. Tumor-induced perturbations in the endocrine, immune and nervous systems drive anorexia and ...catabolic changes in adipose tissue and skeletal muscle, hallmarks of cancer cachexia
. However, the molecular mechanisms driving cachexia remain poorly defined, and there are currently no approved drugs for the condition. Elevation in circulating growth differentiation factor 15 (GDF15) correlates with cachexia and reduced survival in patients with cancer
, and a GDNF family receptor alpha like (GFRAL)-Ret proto-oncogene (RET) signaling complex in brainstem neurons that mediates GDF15-induced weight loss in mice has recently been described
. Here we report a therapeutic antagonistic monoclonal antibody, 3P10, that targets GFRAL and inhibits RET signaling by preventing the GDF15-driven interaction of RET with GFRAL on the cell surface. Treatment with 3P10 reverses excessive lipid oxidation in tumor-bearing mice and prevents cancer cachexia, even under calorie-restricted conditions. Mechanistically, activation of the GFRAL-RET pathway induces expression of genes involved in lipid metabolism in adipose tissues, and both peripheral chemical sympathectomy and loss of adipose triglyceride lipase protect mice from GDF15-induced weight loss. These data uncover a peripheral sympathetic axis by which GDF15 elicits a lipolytic response in adipose tissue independently of anorexia, leading to reduced adipose and muscle mass and function in tumor-bearing mice.
Hydrogen production from the combination of catalytic partial oxidation of methane (CPOM) and water gas shift reaction (WGSR), viz. the two-stage reaction, in a Swiss-roll reactor is investigated ...numerically. Particular emphasis is placed on the interaction among the reaction of CPOM, the cooling effect due to steam injection and the excess enthalpy recovery with heat recirculation. A rhodium (Rh) catalyst bed sitting at the center of the reactor is used to trigger CPOM, and two different WGSRs, with the aids of a high-temperature (Fe–Cr-based) shift catalyst and a low-temperature (Cu–Zn-based) shift catalyst, are excited. Two important parameters, including the oxygen/methane (O/C) ratio and the steam/methane (S/C) ratio, affecting the efficiencies of methane conversion and hydrogen production are taken into account. The predictions indicate that the O/C ratio of 1.2 provides the best production of H
2 from the two-stage reaction. For a fixed O/C ratio, the H
2 yield is relatively low at a lower S/C ratio, stemming from the lower performance of WGSR, even though the cooling effect of steam is lower. On the contrary, the cooling effect becomes pronounced as the S/C ratio is high to a certain extent and the lessened CPOM leads to a lower H
2 yield. As a result, with the condition of gas hourly space velocity (GHSV) of 10,000 h
−1, the optimal operation for hydrogen production in the Swiss-roll reactor is suggested at O/C = 1.2 and S/C = 4–6.
Focal adhesion kinase (FAK) mediates vital cellular pathways during development. Despite its necessity, how FAK regulates and integrates with other signals during early embryogenesis remains poorly ...understood. We found that the loss of Fak1a impaired epiboly, convergent extension and hypoblast cell migration in zebrafish embryos. We also observed a clear disturbance in cortical actin at the blastoderm margin and distribution of yolk syncytial nuclei. In addition, we investigated a possible link between Fak1a and a well-known gastrulation regulator, Wnt5b, and revealed that the overexpression of
or
could cross-rescue convergence defects induced by a
or
antisense morpholino (MO), respectively. Wnt5b and Fak1a were shown to converge in regulating Rac1 and Cdc42, which could synergistically rescue
and
morphant phenotypes. Furthermore, we generated several alleles of
mutants using CRISPR/Cas9, but those mutants only revealed mild gastrulation defects. However, injection of a subthreshold level of the
MO induced severe gastrulation defects in
mutants, which suggested that the upregulated expression of
might complement the loss of Fak1a. Collectively, we demonstrated that a functional interaction between Wnt and FAK signalling mediates gastrulation cell movements via the possible regulation of Rac1 and Cdc42 and subsequent actin dynamics.
This study reports the association between parental uncertainty and characteristics of 123 parent–child dyads prior to the child’s herniorrhaphy. A cross-sectional study design and Mishel’s Parents’ ...Perception of Uncertainty Scale (PPUS) were used. Parent participants were married (98%), had a university degree (45%), identified with a religion (77%), and worked (69%). More boys (76%) than girls (23%) underwent herniorrhaphy (average age = 2.26 years); 60% were the first-born child and 25% were premature. More children presented with unilateral (63.4%; right = 44.7%, left = 18.7%) than bilateral (36.6%) hernias and most were primary (98%). Overall uncertainty was perceived as moderate and ambiguity had the highest score. Religion, birth order (first child), and hernia site (bilateral) explained 20.6% of total variance of uncertainty. Providing information about postoperative symptom and pain management is important for all parents, particularly for parents identified with a religion and whose first-born child had bilateral hernias.
Diabetes is a serious global health problem. Large-scale genome-wide association studies identified loci for type 2 diabetes mellitus (T2DM), including adiponectin (ADIPOQ) gene and transcription ...factor 7-like 2 (TCF7L2), but few studies clarified the effect of genetic polymorphisms of ADIPOQ and TCF7L2 on risk of T2DM. We attempted to elucidate association between T2DM and polymorphic variations of both in Taiwan’s Chinese Han population, with our retrospective case-control study genotyping single nucleotide polymorphisms (SNPs) in ADIPOQ and TCF7L2 genes both in 149 T2DM patients and in 139 healthy controls from Taiwan. Statistical analysis gauged association of these polymorphisms with risk of T2DM to show ADIPOQ rs1501299 polymorphism variations strongly correlated with T2DM risk ( P = 0.042 ) , with rs2241766 polymorphism being not associated with T2DM ( P = 0.967 ) . However, both polymorphisms rs7903146 and rs12255372 of TCF7L2 were rarely detected in Taiwanese people. This study avers that ADIPOQ rs1501299 polymorphism contributes to risk of T2DM in the Taiwanese population.
Methanol steam reforming (MSR) accompanied by methanol decomposition (MD) in an environment with microwave heating is modeled and simulated numerically in the present study. In the developed method, ...the governing equations simultaneously consider the continuity, momentum, energy, species and Maxwell’s equations. Meanwhile, the double absorption of microwaves by both the reactants and the catalyst bed in the reactor is also taken into account. The heating processes of microwaves on the reactants and the catalyst bed are described by establishing two sets of complex relative permittivity in the non-porous and porous region. The permittivity consists of a dielectric constant and a dielectric loss factor. The obtained results indicate that the developed model can predict MSR and MD accurately. With microwave irradiation, it is found that varying dielectric loss factor in the non-porous region has a significant impact on hydrogen production, revealing that the preheating of the reactants plays a prominent role in determining the performance of MSR. Regarding microwave power, it is observed that increasing power intensifies H
2 yield, especially at 500 W where methanol is depleted completely. However, an increase in power also makes MD tend to grow in that the CO
2 selectivity decreases.
Microwave irradiation is an effective route to trigger methanol steam reforming (MSR) for hydrogen production because of the double absorption of microwaves by both the reagents and the catalyst. To ...recognize the thermal characteristic and performance of MSR in an environment with microwave irradiation, a numerical method is employed to predict the coupling phenomena of electromagnetic field, flow field and chemical reactions. Methanol decomposition (MD) is also regarded while MSR proceeds. Two sets of complex relative permittivity are established to account for the transmission of electromagnetic waves to heat reactants in the non-porous zone and the porous zone. Moreover, the effects of heat loss, microwave power and reagent flow rate on MSR are taken into account. The predictions suggest that heat loss is an important factor when the appropriate models with microwave-assisted heating are developed. A higher power is conducive to the performance of MSR, resulting from more heat generated in the reaction tube. At a given microwave power, heat generation due to microwave irradiation is independent of Reynolds number. As a result, increasing Reynolds number lessens methanol conversion and H
2 yield, as a consequence of more reagents passing through the catalyst bed. However, it is of interest that there exists an optimal Reynolds number for MSR to consume heat stemming from microwave irradiation.
► A numerical method is employed to predict the coupling phenomena of electromagnetic field, flow field and chemical reactions. ► Two sets of complex relative permittivity are established to account for the transmission of electromagnetic waves in the non-porous and the porous zones. ► The effects of heat loss, microwave power and reagent flow rate on MSR are taken into account. ► Increasing Reynolds number lessens methanol conversion and H
2 yield. ► There exists an optimal Reynolds number for the performance of MSR.
Introduction
Patients with chronic obstructive pulmonary disease (COPD) frequently experience concurrent comorbidities; therefore, risk assessment for major adverse cardiovascular events (MACEs) is ...very important.
Objectives
We explored the association between COPD and risk of MACEs with three common clinical events: acute myocardial infarction (AMI), ischemic stroke (IS), and cardiovascular death (CVD).
Methods
We evaluated the predictive value of the CHA2DS2‐VASc score (congestive heart failure C, hypertension H, age A, diabetes D, stroke S, and vascular disease VASc) for MACEs in COPD patients. In this observational study, we retrospectively reviewed the records of 29 258 patients with COPD between 2005 and 2009 in relation to MACE risk using the CHA2DS2‐VASc score. We calculated the hazard ratios (HR) and 95% confidence intervals (CI) using a significance level of .05.
Results
Patients with COPD had significantly (P < .001) increased risk of MACEs, and a high prevalence of CHA2DS2‐VASc scores ≥ 6, predicting MACEs (16.1%), AMI (3.3%), IS (8.7%), and CVD (4.0%). A good discrimination was found for MACEs, IS events, and CVD events (AUC = 0.740, 0.739, and 0.778, respectively) but poorer discrimination for AMI events (AUC = 0.697).
Conclusion
Early lifestyle modifications and antithrombotic therapy may be essential for COPD patients at a high risk of MACEs, that is, those with CHA2DS2‐VASc scores ≥ 6.
The hysteresis characteristics of catalytic partial oxidation of methane (CPOM) in a Swiss-roll reactor are predicted numerically by varying Damköhler number. Particular attention is paid to the ...influences of heat recirculation, gas hourly space velocity (GHSV), and atomic O/C ratio on the hysteresis loop and performance of CPOM. The reactions of methane combustion, steam reforming, and CO2 or dry reforming are simultaneously considered. The results reveal that preheating reactants through excess enthalpy recovery is conducive to the ignition of CPOM and extending its extinction limit, so the ignition and extinction Damköhler numbers are lowered. The analysis also suggests that steam reforming is more sensitive to the heat recovery than methane combustion and dry reforming. An increase in GHSV reduces the residence time of reactants in the catalyst bed, thereby enlarging the ignition and extinction Damköhler numbers of CPOM. A higher O/C ratio facilitates the ignition of CPOM, stemming from more oxygen supplied, but the ratio should be controlled below 1.2. From the hysteresis phenomena, hydrogen can be produced from methane at a lower Damköhler number to save more energy for performing CPOM.
•Hysteresis characteristics of catalytic partial oxidation of methane are studied•A Swiss-roll reactor is adopted.•Methane combustion, steam reforming, and dry reforming are considered.•Preheating reactants facilitates extending the extinction limit of CPOM.•Energy for hydrogen production can be saved via hysteresis phenomena
PDF
