Nephropathy due to BK virus (BKV) infection is an evolving challenge in patients undergoing hematopoietic stem cell transplantation (HSCT). We hypothesized that BKV infection was a marker of kidney ...function decline and a poor prognostic factor in HSCT recipients who experience this complication. In this retrospective study, we analyzed all patients who underwent their first allogeneic HSCT at our institution between 2004 and 2012. We evaluated the incidence of persistent kidney function decline, which was defined as a confirmed reduction in estimated glomerular filtration rate of at least 25% from baseline using the Chronic Kidney Disease Epidemiology equation. Cox proportional hazard regression was used to model the cause‐specific hazard of kidney function decline, and the Fine–Gray method was used to account for the competing risks of death. Among 2477 recipients of a first allogeneic HSCT, BK viruria was detected in 25% (n = 629) and kidney function decline in 944 (38.1%). On multivariate analysis, after adjusting for age, sex, acute graft‐versus‐host disease (GVHD), chronic GVHD, preparative conditioning regimen, and graft source, BK viruria remained a significant risk factor for kidney function decline (p < 0.001). In addition, patients with BKV infection and kidney function decline experienced worse overall survival. After allogeneic HSCT, BKV infection was strongly and independently associated with subsequent kidney function decline and worse patient survival after HSCT.
In a retrospective review of 2477 patients after allogeneic hematopoietic stem cell transplantation, the authors strongly and independently associate BKV infection with subsequent kidney function decline and worse patient survival.
The past two decades of research on Carbon Capture and Storage (CCS) seem to have finally become fruitful as global leaders and energy-intensive industries are cooperating to materialize CCS projects ...and reach the promised reduction in CO2 emissions. Traditionally, CCS projects targeted mostly high permeability sandstone formations, despite the numerous carbonate fields undergoing CO2 injection for Enhanced Oil Recovery (EOR) in the United States or Canada. Because of the reactivity between calcite minerals and CO2 saturated water, chalk formations, characterized by high porosity and low permeability, have been previously portrayed as infeasible CO2 storage sites. Although previous laboratory investigations were carried out to assess the performance of CO2-EOR in North Sea chalk fields, these studies did not result in any field-scale demonstration projects; this may soon change since a positive movement towards CO2 storage in depleted oil fields has been recently initiated. In this work, we reviewed existing studies on CO2 injection in chalk to address the suitability of this type of formation for CCS. Although the evidence on the thermo-hydro-mechanical-chemical behaviour of chalk in the presence of CO2-saturated aqueous solutions is mixed, the majority of flooding tests performed on reservoir core samples do not support further weakening relative to water injection conditions nor significant changes in the petrophysical properties. Along with the weakening effect and using the Danish North Sea chalk fields as a case study, we addressed events that impact the storage site safety such as fault reactivation, and caprock and well integrity. Furthermore, monitoring techniques relevant to offshore locations are also discussed. Based on studies on other types of carbonates, and considering the characteristics of chalk (e.g., permeability, wettability, and reactivity) we analysed the relevance of different trapping mechanisms (i.e., solution, capillary, and mineral) but also several effects (i.e., chemical, biological, mechanical) that can lead to loss of injectivity. The main observations and conclusions in this work can be easily extrapolated to other chalk formations worldwide.
•A growing number of countries are contemplating CO2 storage to reduce CO2 emissions•Existing research largely leans towards CO2 storage in highly permeable formations•Global deployment of CO2 storage can benefit by diversifying the lithology options•Porous chalk formations can represent reliable CO2 storage sites.
Biological tissue, pharmaceutical tablets, wood, porous rocks, catalytic reactors, concrete, and foams are examples of heterogeneous systems that may contain one or several fluid phases. Fluids in ...such systems carry chemical species that may participate in chemical reactions in the bulk of a fluid, as homogeneous reactions, or at the fluid/fluid or fluid/solid interfaces, as heterogeneous reactions. Magnetic resonance relaxation measures the return of
1
H nuclear magnetization in chemical species of these fluids to an equilibrium state in a static magnetic field. Despite the perceived difference between reaction–diffusion and relaxation–diffusion in heterogeneous systems, similarities between the two are remarkable. This work draws a close parallel between magnetic resonance relaxation–diffusion and chemical reaction–diffusion for elementary unitary reaction
A
→
B
in a dilute solution—both in heterogeneous systems. A striking similarity between the dimensionless numbers that characterize their relevant behavior is observed: the Damköhler number of the second kind
Da
II
for reaction and the Brownstein–Tarr number
BT
i
for relaxation. The new vision of analogy between reaction- and magnetic resonance relaxation–diffusion in heterogeneous systems encourages the exploitation of similarities between reaction and relaxation processes to noninvasively investigate the dynamics of chemical species and reactions. One such example of importance in chemical engineering is provided for solid–fluid reaction in packed beds.
Magnetic resonance is an important noninvasive technology across life sciences and industry. Free induction decay is the simplest
1
H magnetic resonance measurement method and an important means of ...probing fast-decaying signals in porous materials such as rocks, lung, and bone. It is commonly assumed that the free induction decay in geological porous materials is single-exponential. We experimentally observed two regimes of free induction decay behavior in geological porous materials: single-exponential and non-exponential decay. Numerical simulations that match experimental data highlight the effect of mass diffusion, especially in the single-exponential behavior. These two regimes of free induction decay in porous materials are associated with a bifurcation point in the solutions of the Bloch–Torrey equation for diffusion of fluids in confined domains in the presence of internal magnetic field gradients. This finding facilitates the extraction of absolute internal magnetic field gradient intensities from simple free induction decay measurements in the laboratory and field. This work also warns against common single-exponential assumptions in surface magnetic resonance methods employed in surveying underground water aquifers.
Graphic Abstract
In this paper, impact loading results from numerical simulations of plain concrete (PC) and fiber-reinforced concrete (FRC) are compared with experimental testing data, which were based on a testing ...procedure recommended by ACI committee 544. Concrete specimens were prepared with two water–cement ratios 0.36 and 0.46. Hooked-end steel fibers with an aspect ratio equal of 80 at 0.5% and 1% volume fractions and polypropylene fibers at 0.2%, 0.3% and 0.5% volume fractions were used. Both the numerical and experimental analysis results indicated that increasing the fiber volume fraction increased the impact resistance of the concrete specimens. The impact resistance increase was greater for normal-strength than that for high-strength concrete. The results also demonstrated that steel fibers are more effective at increasing impact resistance than polypropylene fibers.
► Adding fibers to concrete increases its compressive and tensile strengths. ► Fibers improve the concrete performance against the first crack initiation. ► Fibers improve the concrete performance against the final fracture. ► Steel fibers with hooked-ends have a better performance than polypropylene fibers.
Summary
During the past decade several notable viruses have suddenly emerged from obscurity or anonymity to become serious global health threats, provoking concern regarding their sustained epidemic ...transmission in immunologically naive human populations. With each new threat comes the call for rapid vaccine development. Indeed, vaccines are considered a critical component of disease prevention for emerging viral infections because, in many cases, other medical options are limited or non‐existent, or that infections result in such a rapid clinical deterioration that the effectiveness of therapeutics is limited. While classic approaches to vaccine development are still amenable to emerging viruses, the application of molecular techniques in virology has profoundly influenced our understanding of virus biology, and vaccination methods based on replicating, attenuated and non‐replicating virus vector approaches have become useful vaccine platforms. Together with a growing understanding of viral disease emergence, a range of vaccine strategies and international commitment to underpin development, vaccine intervention for new and emerging viruses may become a possibility.
The application of molecular techniques in virology has profoundly influenced our understanding of virus biology. Vaccination methods based on replicating, attenuated and non‐replicating virus vector approaches have become useful vaccine platforms. Together with a growing understanding of viral disease emergence, a range of vaccine strategies and international commitment to underpin development, vaccine intervention for new and emerging viruses may become a possibility.
Hafeshjan is one of the most important centers for cutting and producing stone works (tombstones and stone lions). hafshjani stone carving artists have been engaged in this profession for generations ...and are now one of the active centers in the production of various types of stone works is includes a variety of tombstones, ritual and decorative stone lions and other functional and decorative stone volumes. this article is a field research that has been written with the aim of introducing different types of volumetric and stone works of hafshejan, examining, identifying and analyzing aesthetic aspects and knowing the reason for the formation of motifs in their context. the main question of the research is: what are the types of tombstones and stone lions of Hafshjan, the reason for their production and the aesthetic dimensions and decorative motifs of these works and what are their meanings? the findings of this study are based on field studies, some of which are: hafshejan stone works in the past included tombstones and stone lions, but today, in addition to its innovative production, various functional works (types of dishes) and decorative works (types of stone lions) are also produced. the production of lions in
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