► Ternary separation of benzene–toluene–xylene in a dividing-wall column. ► Rigorous simulations carried out in AspenTech Aspen Plus and Aspen Dynamics. ► Energy efficient control strategies based on ...most used PID control loops. ► Liquid split manipulation for implicit minimization of energy requirements. ►
DB/
LSV and
LB/
DSV exhibit relatively short settling times and low overshooting.
Dividing-wall column (DWC) is considered nowadays the new champion in distillation, as it can bring substantial reduction in the capital invested as well as savings in the operating costs. This work presents the simulation results of energy efficient control and dynamics of a dividing-wall column (DWC). In order to allow a fair comparison of the results with previously published references, the case-study considered here is the industrially relevant ternary separation of the mixture benzene–toluene–xylene (BTX) in a DWC. Rigorous simulations were carried out in Aspen Plus and Aspen Dynamics. Several conventional control structures based on PID control loops (
DB/
LSV,
DV/
LSB,
LB/
DSV,
LV/
DSB) were used as a control basis. These control structures were enhanced by adding an extra loop controlling the heavy component composition in the top of the prefractionator, by using the liquid split as an additional manipulated variable, thus implicitly achieving minimization of energy requirements. The results of the dynamic simulations show relatively short settling times and low overshooting especially for the
DB/
LSV and
LB/
DSV control structures. Moreover, the energy efficient control proposed in this work allows the operation of DWC with minimum energy requirements or maximum purity of products.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In spite of claiming around half of the operational costs of chemical plants, distillation is still the most popular separation technology. Distillation has low thermodynamic efficiency, requiring ...the input of high quality energy in the reboiler – while rejecting a similar amount of heat at lower temperature, in the condenser. Several heat pump concepts have been proposed to upgrade that thermal energy and reduce the consumption of valuable utilities. Under certain conditions, the energy savings of heat pump assisted distillation is usually around 20–50%.
This study proposes a novel selection scheme of energy efficient distillation technologies, with a special focus on heat pumps. The most promising technologies selected are vapor compression, mechanical or thermal vapor recompression, absorption, compression–resorption and thermo-acoustic heat pumps, multi-effect distillation, heat integrated distillation column, cyclic distillation, Kaibel and dividing-wall column. The scheme considers as the main selection criteria the type of separation tasks, product flow and specifications, operating pressure, difference in boiling points, reboiler duty and its temperature level. Moreover, this scheme is very practical, allowing major time and resources savings in the design of eco-efficient processes.
▸ Heat pump assisted distillation with energy savings of 20–50%. ▸ Novel and practical selection scheme of energy efficient distillation technologies. ▸ Evaluation of promising technologies: VC, MVR, TVR, AHP, CHRP, TAHP, HIDiC, DWC, CyDist. ▸ Selection criteria include: ΔTb, ΔTlift, P, Treb, Qreb, volatility. ▸ Design of eco-efficient processes with high COP, and lower TIC and TAC.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Research gaps in understanding flood changes at the catchment scale caused by changes in forest management, agricultural practices, artificial drainage, and terracing are identified. Potential ...strategies in addressing these gaps are proposed, such as complex systems approaches to link processes across time scales, long‐term experiments on physical‐chemical‐biological process interactions, and a focus on connectivity and patterns across spatial scales. It is suggested that these strategies will stimulate new research that coherently addresses the issues across hydrology, soil and agricultural sciences, forest engineering, forest ecology, and geomorphology.
Plain Language Summary
This commentary explores research gaps in the field of land use change impacts on floods at the catchment scale and proposes possible ways forward for addressing these gaps. Specifically the impacts of forest management, agricultural practices, artificial drainage, and terracing on flood generation at the catchment scale are explored. Potential strategies in addressing research gaps in these fields are complex systems approaches to link processes across time scales, long‐term experiments on physical‐chemical‐biological process interactions, and a focus on connectivity and patterns across spatial scales. It is suggested that these strategies will stimulate new research that coherently addresses the issues across hydrology, soil and agricultural sciences, forest engineering, forest ecology, and geomorphology.
Key Points
Land use change impacts on floods are poorly understood at the catchment scale
Numerous synergies are identified in exploring the effects of changed agricultural practices, artif. drainage, terracing, and forest cover
A cross‐disciplinary systems approach aided by long‐term field studies and a focus on flow connectivity are needed to make major advances
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Cajal (coiled) bodies are conserved subnuclear organelles that are present in the nucleoplasm of both animal and plant cells. Although Cajal bodies were first described nearly 100 years ago, their ...function has remained largely speculative. Here, we describe a novel class of human small nuclear RNAs that localize specifically to Cajal bodies. The small Cajal body‐ specific RNAs (scaRNAs) are predicted or have already been demonstrated to function as guide RNAs in site‐specific synthesis of 2′‐O‐ribose‐methylated nucleotides and pseudouridines in the RNA polymerase II‐transcribed U1, U2, U4 and U5 spliceosomal small nuclear RNAs (snRNAs). Our results provide strong support for the idea that the Cajal body, this mysterious nuclear organelle, provides the cellular locale for post‐transcriptional modification of spliceosomal snRNAs.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Background and Purpose
Emerging evidence suggests a selective up‐regulation of arginase I in diabetes causing coronary artery disease; however, the mechanisms behind this up‐regulation are still ...unknown. Activated p38 MAPK has been reported to increase arginase II in various cardiovascular diseases. We therefore tested the role of p38 MAPK in the regulation of arginase I and II expression and its effect on endothelial dysfunction in diabetes mellitus.
Experimental Approach
Endothelial function was determined in septal coronary (SCA), left anterior descending coronary (LAD) and mesenteric (MA) arteries from healthy and streptozotocin‐induced diabetic Wistar rats by wire myographs. Arginase activity and protein levels of arginase I, II, phospho‐p38 MAPK and phospho‐endothelial NOS (eNOS) (Ser1177) were determined in these arteries from diabetic and healthy rats treated with a p38 MAPK inhibitor in vivo.
Key Results
Diabetic SCA and MA displayed impaired endothelium‐dependent relaxation, which was prevented by arginase and p38 MAPK inhibition while LAD relaxation was not affected. Arginase I, phospho‐p38 MAPK and eNOS protein expression was increased in diabetic coronary arteries. In diabetic MA, however, increased expression of arginase II and phospho‐p38 MAPK, increased arginase activity and decreased expression of eNOS were observed. All these effects were reversed by p38 MAPK inhibition.
Conclusions and Implications
Diabetes‐induced activation of p38 MAPK causes endothelial dysfunction via selective up‐regulation of arginase I expression in coronary arteries and arginase II expression in MA. Therefore, regional differences appear to exist in the arginase isoforms contributing to endothelial dysfunction in type 1 diabetes mellitus.
Full text
Available for:
BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
Background. Eradication of methicillin-resistant Staphylococcus aureus (MRSA) carriage may reduce the risk of MRSA infection and prevent transmission of the organism to other patients. Methods. To ...determine the efficacy of decolonization therapy, patients colonized with MRSA were randomized (3 : 1 allocation) to receive treatment (2% chlorhexidine gluconate washes and 2% mupirocin ointment intranasally, with oral rifampin and doxycycline for 7 days), or no treatment. Follow-up samples for MRSA culture were obtained from the nares, perineum, skin lesions, and catheter exit sites monthly for up to 8 months. The primary outcome measure was detection of MRSA at 3 months of follow-up. Univariate and multivariable analyses were performed to identify variables associated with treatment failure. Results. Of 146 patients enrolled in the study, 112 patients (87 treated; 25 not treated) were followed up for at least 3 months. At 3 months of follow-up, 64 (74%) of those treated had culture results negative for MRSA, compared with 8 (32%) of those not treated (P = .0001). This difference remained significant at 8 months of follow-up, at which time, 54% of those treated had culture results negative for MRSA (χ2 = 64.4; P < .0001, by log-rank test). The results of the multivariable analysis indicated that having a mupirocin-resistant isolate at baseline was associated with treatment failure (relative risk, 9.4; 95% confidence interval, 2.8–31.9; P = .0003), whereas decolonization therapy was protective (relative risk, 0.1; 95% confidence interval, 0.04–0.4; P = .0002). Mupirocin resistance emerged in only 5% of follow-up isolates. Conclusions. Treatment with topical mupirocin, chlorhexidine gluconate washes, oral rifampin, and doxycycline for 7 days was safe and effective in eradicating MRSA colonization in hospitalized patients for at least 3 months.
Full text
Available for:
BFBNIB, NUK, PNG, UL, UM, UPUK
Antarctic Bottom Water (AABW), which fills the global ocean abyss, is derived from dense water that forms in several distinct Antarctic shelf regions. Previous modeling studies have reached ...conflicting conclusions regarding export pathways of AABW across the Southern Ocean and the degree to which AABW originating from distinct source regions are blended during their export. This study addresses these questions using passive tracer deployments in a 61‐year global high‐resolution (0.1°) ocean/sea‐ice simulation. Two distinct export “conduits” are identified: Weddell Sea‐ and Prydz Bay‐sourced AABW are blended together and exported mainly to the Atlantic and Indian Oceans, while Ross Sea‐ and Adelie Land‐sourced AABW are exported mainly to the Pacific Ocean. Northward transport of each tracer occurs almost exclusively (>90%) within a single conduit. These findings imply that regional changes in AABW production may impact the three‐dimensional structure of the global overturning circulation.
Plain Language Summary
Cooling, ice formation, and mixing near Antarctica create dense ocean waters, known as Antarctic Bottom Water (AABW). Due to their high density, these waters sink and propagate northward to fill the deepest parts of the Southern, Indian, Pacific, and Atlantic Oceans. Hence AABW export has a significant and near‐global impact on deep‐ocean circulation and the distribution of physical properties (e.g., salinity, temperature, dissolved oxygen). However, AABW transport pathways are only partially understood. Here we investigate the transport pathways of AABW from its four principal formation regions, using a state‐of‐the‐art numerical simulation of Earth's oceans. We find that the export occurs via two distinct pathways (“conduits”). The geographical boundaries between these conduits occur near seafloor ridges, and little AABW exchange occurs across them. Circulation pathways within each conduit blend together AABW formed in two of the four main formation regions, and export them to different oceans. Identification of these pathways elucidates the origin of observed trends in AABW properties, and helps to predict where these changes may propagate in the coming decades.
Key Points
Antarctic Bottom Water (AABW) export pathways across the Southern Ocean are investigated in a high‐resolution (0.1°) numerical model
Weddell‐ and Prydz‐sourced AABW tracers blend together before crossing the Southern Ocean, as do Ross‐ and Adelie‐sourced AABW tracers
Weddell/Prydz‐sourced (Ross/Adelie‐sourced) AABW tracers primarily supply the Atlantic and Indian Oceans (Pacific Ocean)
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Since there is sound evidence that communication skills training (CST) programs modify communication behavior of oncology clinicians, they have been widely implemented over the last decades. However, ...more recently, certain aspects of this training have been criticized.
Based on this background, a call to re-launch a discussion about the future of CST led to the third European consensus meeting on communication in cancer care, organized by the Swiss Cancer League. During this meeting, which brought together European experts in the field of clinical communication and training of communication in the oncology setting, oncology clinicians, representatives of the European Society of Medical Oncology and a member of the European Oncology Nursing Society, the recommendations of the second European consensus meeting were updated and expanded.
The expanded recommendations recall the guiding principles of communication in cancer care, underline the important role of clinician’s self-awareness, and of relational and contextual factors in clinical communication, and provide direction for the further development of communication training.
This third European consensus meeting defines key elements for the development of a next generation of communication training for oncology clinicians.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this study, we present the synthesis, characterization and
in vitro
cytotoxicity of six organometallic Ru(
ii
)(η
6
-
p
-cymene)(
N
,
N
)ClCl, Rh(
iii
)(η
5
-C
5
Me
5
)(
N
,
N
)ClCl and Re(
i
...)(CO)
3
(
N
,
N
)Cl complexes, in which the (
N
,
N
) ligands are sterane-based 2,2′-bipyridine derivatives (4-Me-bpy-St-OH, 4-Ph-bpy-St-OH). The solution chemical behavior of the ligands and the complexes was explored by UV-visible spectrophotometry and
1
H NMR spectroscopy. The ligands and their Re(
i
) complexes are neutral at pH = 7.40; this contributes to their highly lipophilic character (log
D
7.40
> +3). The Ru(
ii
) and Rh(
iii
) half-sandwich complexes are much more hydrophilic, and this property is greatly affected by the actual chloride ion content of the medium. The half-sandwich Ru and Rh complexes are highly stable in 30% (v/v) DMSO/water (<5% dissociation at pH = 7.40); this is further increased in water. The Rh(
iii
)(η
5
-C
5
Me
5
) complexes were characterized by higher water/chloride exchange and p
K
a
constants compared to their Ru(
ii
)(η
6
-
p
-cymene) counterparts. The Re(
i
)(CO)
3
complexes are also stable in solution over a wide pH range (2-12) without the release of the bidentate ligand; only the chlorido co-ligand can be replaced with OH
−
at higher pH values. A comprehensive discussion of the binding affinity of the half-sandwich Ru(
ii
) and Rh(
iii
) complexes toward human serum albumin and calf-thymus DNA is also provided. The Ru(
ii
)(η
6
-
p
-cymene) complexes interact with human serum albumin
via
intermolecular forces, while for the Rh(
iii
)(η
5
-C
5
Me
5
) complexes the coordinative binding mode is suggested as well. They are also able to interact with calf-thymus DNA, most likely
via
the coordination of the guanine nitrogen. The Ru(
ii
)(η
6
-
p
-cymene) complexes were found to be the most promising among the tested compounds as they exhibited moderate-to-strong cytotoxic activity (IC
50
= 3-11 μM) in LNCaP as well as in PC3 prostate cells in an androgen receptor-independent manner. They were also significantly cytotoxic in breast and colon adenocarcinoma cancer cell lines and showed good selectivity for cancer cells.
Synthesis, characterization, solution speciation, binding affinity towards biomolecules and anticancer activity of organometallic Ru(
ii
), Rh(
iii
) and Re(
i
) complexes of (
N
,
N
) donor 5α-dihydrotestosterone-based hybrid ligands.
PDF
