bluuebunny/crossref_metadata_2025_split huggingface dataset:
A comparative study of heavy oil oxidation thermal behavior in the presence of Cu-Mn tallates
Authors: Khelkhal M , Eskin A , Vakhin A 
Published: July 2019

Abstract
Heavy oil in-situ combustion process has many benefits among other thermal enhancing oil recovery methods. However, its application is still a complex task due to the irregular propagation of combustion front in the reservoir and its early breaking down. Recent finding regarding in-situ combustion development have led to use catalysts based on transition metals in order to stabilize and enhance combustion front flow. Transition metals was chosen rather than other types of catalysts because of their practical, feasible and economic impact in a wide range of industrial processes.
Current solutions to catalytic in-situ combustion are inconsistent with their application in real fields due the problems associated to the injection of catalysts in the reservoir from one side and to the high cost that can be generated from the use of certain type of catalysts. In this context, we studied the effect of copper and manganese tallates in different metal ratios on the oxidation of heavy oil by applying various physical and physical-chemical methods. As a result, we have obtained accurate results demonstrating the potential effect of Cu-Mn tallates in stabilizing combustion front during high temperature oxidation reactions.
Aquathermolysis of heavy oil in the presence of supercritical water
Authors: Petrov S. , Soldatova R. , Lakhova A. 
Published: July 2019

Abstract
The purpose of the work is to identify patterns of transformation of high-molecular components of super-heavy oil by hydrothermal-catalytic processes, namely in the presence of a supercritical state of water. The regularities of changes of the component, structural-group, fractional and elemental compositions of heavy oil during the conversion under the above conditions were established, rheological characteristics of the initial crude oil and converted oil were studied as well. As a result of carrying out aquathermolysis in the supercritical water environment and in the presence of carbonaceous substances, the high-molecular weight components of the initial crude oil were degraded with the formation of light distillate fractions, which were scarcely present in the initial crude oil.
Natural heavy oil reservoirs porosity and saturation coefficients estimation based on wavelet analysis of X-Ray computed tomography histogram
Authors: Kadyrov R , Starovoytov A , Utemov E , Statsenko E , Sagirov R , Validov M 
Published: July 2019

Abstract
With the development of unconventional resources the standard task of evaluation the porosity and oil saturation needs new approach. Heavy oil and bitumen can act as cement in many sand reservoirs, which excludes the use of standard measuring techniques. A new method for estimating the porosity and oil saturation of heavy oil reservoirs, based on wavelet X-ray computed tomography histogram analysis, was proposed. Its advantages are the ability to work with loose sand reservoirs, for which it is not possible to use standard assessment methods. A comparative analysis of the proposed method with a standard method for estimating porosity based on sample saturation with kerosene showed that the values of the porosity coefficient in the tomography resolution range 5-15 μm differed by 3-7% in the direction of the wavelet analysis method. This effect is due to the presence of transient voxels – mixels.
Stages of thermal transformation of oil shales organic-mineral substance of the Middle Volga region during combustion
Authors: Korolev E , Eskin A , Korolev A , Barieva E 
Published: July 2019

Abstract
The study of the staging of the thermal conversion of oil shale, common in the Middle Volga region, was carried out. It is established that the organic matter of rocks due to the polycomponent composition undergoes multi-stage pyrolysis in the temperature range 200-600°C. The most favorable temperature of pyrolysis, when up to 80% of the potential heat of shale is released, falls within the interval of 460-480°C. The main thermal transformations of the ash component are carried out at temperatures above 480°C. They are due to the release from the structure of clay minerals of the OH group, the oxidation of pyrite, the decomposition of calcite and the formation of spinels.
Summing up the obtained results, we can draw to the following conclusions:
1. Oil shale of the Middle Volga region is characterized by significant variations in the content of organic matter from 9 to 40%. The light isotopes C12 predominance in the composition of organic carbon indicates the predominantly biochemical origin of the organic matter.
2. The configuration of the DSC curve in the temperature range of 200–600°C indicates both the multicomponent composition of the organic compounds of oil shale and their multi-stage pyrolysis.
3. The most favorable pyrolysis temperature, when up to 80% of the potential heat of shale is released, is in the range of 460-480°C.
4. In the process of burning oil shale, the ash component of the rock also subjected to thermal transformation. The composition of rock-forming minerals determined the main temperature ranges of transformation in the areas of 480–600°C (extraction of hydroxyl water from clays, oxidation of pyrite with the formation of hematite), 680–800°C (destruction of calcite), 880–900°C (formation of spinels).
Influence of formation conditions on reservoir thickness and reservoir properties
Authors: Uspensky B V , Khaliullina S V , Valeeva S E , Vafin R F 
Published: July 2019

Abstract
Authors of the article identified the influence of sedimentation conditions on reservoir thickness and the patterns of change in reservoir properties of superviscous oil field from the following three zones of the sandstone sequence of the Sheshminsky horizon: Northern, Southern and Central identified by PJSC Tatneft and prepared for initial development. The following relationships have been investigated: open porosity relation with bitumen content (by weight and by volume), open porosity relation with carbonate content, open porosity relation with bulk density, carbonate content relation with bulk density, bitumen content (by weight and by volume) relation with carbonate content, and also bitumen content relation with their depth. The revealed patterns of changes in reservoir properties and bitumen content within the sandstone sequence can be the result of not only changing conditions of sedimentation, but also the result of post-sedimentation processes resulting in calcitization or redistribution of carbonate cement in the rock under the influence of aggressive products (oxidation, biodegradation) of oil deposits destruction.
Fabrication of free standing collagen membranes by pulsed-electrophoretic deposition
Authors: Barrett David J , Linley Matthew D , Best Serena M , Cameron Ruth E 
Published: July 2019

AbstractThis work reports an important new development in the production of collagen membranes, based on pulsed electrophoretic deposition (P-EPD), suitable for a wide range of biomedical applications. Collagen membranes are of great interest as a biomaterial and in a range of other industries, though current production techniques suffer from limitations with scaling up, homogeneity, and complex shapes. P-EPD can be used to rapidly create detachable, large-area, homogeneous products with controlled thickness in a wide variety of shapes. We provide a new understanding of the influence of a range of parameters (pulse width, voltage, duty cycle, solvent additions) and their effects on membrane structure. Characterisation by AFM, SEM, and cryoSEM revealed the ability to produce dense, structurally defect-free membranes, and significantly, we show and discuss the ability to produce thicker membranes by sequential deposition without seeing a corresponding increase in cell electrical resistance. We anticipate this novel, rapid, and controllable method for the production of collagen membranes to be of interest for a wide range of fields.
Operator functions and the operator harmonic mean
Authors: Uchiyama Mitsuru 
Published: July 2019

The objective of this paper is to investigate operator functions by making use of the operator harmonic mean ‘

!

\,!\,

’. For

0
>
A
≦
B

0>A\leqq B

, we construct a unique pair

X
X

,

Y
Y

such that

0
>
X
≦
Y
,

A
=
X

!

Y
,

B
=

X
+
Y

2

0>X\leqq Y, \; A=X\,!\,Y,\; B=\frac {X+Y}{2}

. We next give a condition for operators

A
,
B
,
C
≧
0

A, B, C\geqq 0

in order that

C
≦
A

!

B

C \leqq A\,!\ B

and show that

g
≠
0

g\ne 0

is strongly operator convex on

J
J

if and only if

g
(
t
)
>
0

g(t)>0

and

g
(

A
+
B

2

)
≦
g
(
A
)

!

g
(
B
)

g (\frac {A+B}{2}) \leqq g(A)\,!\,g(B)

for

A
,
B

A, B

with spectra in

J
J

. This inequality particularly holds for an operator decreasing function on the right half line. We also show that

f
(
t
)

f(t)

defined on

(
0
,
b
)

(0, b)

with

0
>
b
≦
∞

0>b\leqq \infty

is operator monotone if and only if

f
(
0
+
)
>
∞
,

f
(
A

!

B
)
≦

1
2

(
f
(
A
)
+
f
(
B
)
)

f(0+)>\infty , \;f (A\,!\,B)\leqq \frac {1}{2}(f(A) + f(B))

. In particular, if

f
>
0

f>0

, then

f
f

is operator monotone if and only if

f
(
A

!

B
)
≦
f
(
A
)

!

f
(
B
)

f (A\, !\, B) \leqq f(A)\, !\, f(B)

. We lastly prove that if a strongly operator convex function

g
(
t
)
>
0

g(t)>0

on a finite interval

(
a
,
b
)

(a, b)

is operator decreasing, then

g
g

has an extension

g
~

\tilde {g}

to

(
a
,
∞
)

(a, \infty )

that is positive and operator decreasing.
The pivotal roles of the NOD-like receptors with a PYD domain, NLRPs, in oocytes and early embryo development†
Authors: Amoushahi Mahboobeh , Sunde Lone , Lykke-Hartmann Karin 
Published: July 2019

Abstract
Nucleotide-binding oligomerization domain (NOD)-like receptors with a pyrin domain (PYD), NLRPs, are pattern recognition receptors, well recognized for their important roles in innate immunity and apoptosis. However, several NLRPs have received attention for their new, specialized roles as maternally contributed genes important in reproduction and embryo development. Several NLRPs have been shown to be specifically expressed in oocytes and preimplantation embryos. Interestingly, and in line with divergent functions, NLRP genes reveal a complex evolutionary divergence. The most pronounced difference is the human-specific NLRP7 gene, not identified in rodents. However, mouse models have been extensively used to study maternally contributed NLRPs. The NLRP2 and NLRP5 proteins are components of the subcortical maternal complex (SCMC), which was recently identified as essential for mouse preimplantation development. The SCMC integrates multiple proteins, including KHDC3L, NLRP5, TLE6, OOEP, NLRP2, and PADI6. The NLRP5 (also known as MATER) has been extensively studied. In humans, inactivating variants in specific NLRP genes in the mother are associated with distinct phenotypes in the offspring, such as biparental hydatidiform moles (BiHMs) and preterm birth. Maternal-effect recessive mutations in KHDC3L and NLRP5 (and NLRP7) are associated with reduced reproductive outcomes, BiHM, and broad multilocus imprinting perturbations. The precise mechanisms of NLRPs are unknown, but research strongly indicates their pivotal roles in the establishment of genomic imprints and post-zygotic methylation maintenance, among other processes. Challenges for the future include translations of findings from the mouse model into human contexts and implementation in therapies and clinical fertility management.
Strategies for validating biomarkers using data from a reference set
Authors: Wang Lu , Huang Ying , Feng Ziding 
Published: July 2019

SummaryCandidate biomarkers discovered in the laboratory need to be rigorously validated before advancing to clinical application. However, it is often expensive and time-consuming to collect the high quality specimens needed for validation; moreover, such specimens are often limited in volume. The Early Detection Research Network has developed valuable specimen reference sets that can be used by multiple labs for biomarker validation. To optimize the chance of successful validation, it is critical to efficiently utilize the limited specimens in these reference sets on promising candidate biomarkers. Towards this end, we propose a novel two-stage validation strategy that partitions the samples in the reference set into two groups for sequential validation. The proposed strategy adopts the group sequential testing method to control for the type I error rate and rotates group membership to maximize the usage of available samples. We develop analytical formulas for performance parameters of this strategy in terms of the expected numbers of biomarkers that can be evaluated and the truly useful biomarkers that can be successfully validated, which can provide valuable guidance for future study design. The performance of our proposed strategy for validating biomarkers with respect to the points on the receiver operating characteristic curve are evaluated via extensive simulation studies and compared with the default strategy of validating each biomarker using all samples in the reference set. Different types of early stopping rules and boundary shapes in the group sequential testing method are considered. Compared with the default strategy, our proposed strategy makes more efficient use of the limited resources in the reference set by allowing more candidate biomarkers to be evaluated, giving a better chance of having truly useful biomarkers successfully validated.
Advanced glycation endproducts and dicarbonyls in end-stage renal disease: associations with uraemia and courses following renal replacement therapy
Authors: Martens Remy J H , Broers Natascha J H , Canaud Bernard , Christiaans Maarten H L , Cornelis Tom , Gauly Adelheid , Hermans Marc M H , Konings Constantijn J A M , van der Sande Frank M , Scheijen Jean L J M , Stifft Frank , Kooman Jeroen P , Schalkwijk Casper G 
Published: July 2019

Abstract

Background
End-stage renal disease (ESRD) is strongly associated with cardiovascular disease (CVD) risk. Advanced glycation endproducts (AGEs) and dicarbonyls, major precursors of AGEs, may contribute to the pathophysiology of CVD in ESRD. However, detailed data on the courses of AGEs and dicarbonyls during the transition of ESRD patients to renal replacement therapy are lacking.

Methods
We quantified an extensive panel of free and protein-bound serum AGEs [N∈-(carboxymethyl)lysine (CML), N∈-(carboxyethyl)lysine (CEL), Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)ornithine (MG-H1)], serum dicarbonyls [glyoxal (GO), methylglyoxal (MGO), 3-deoxyglucosone (3-DG)] and tissue AGE accumulation [estimated by skin autofluorescence (SAF)] in a combined cross-sectional and longitudinal observational study of patients with ESRD transitioning to dialysis or kidney transplantation (KTx), prevalent dialysis patients and healthy controls. Cross-sectional comparisons were performed with linear regression analyses, and courses following renal replacement therapy were analysed with linear mixed models.

Results
Free and protein-bound AGEs, dicarbonyls and SAF were higher in chronic kidney disease (CKD) Stage 5 non-dialysis (CKD 5-ND; n = 52) and CKD Stage 5 dialysis (CKD 5-D; n = 35) than in controls (n = 42). In addition, free AGEs, protein-bound CML, GO and SAF were even higher in CKD 5-D than in CKD5-ND. Similarly, following dialysis initiation (n = 43) free and protein-bound AGEs, and GO increased, whereas SAF remained similar. In contrast, following KTx (n = 21), free and protein-bound AGEs and dicarbonyls, but not SAF, markedly declined.

Conclusions
AGEs and dicarbonyls accumulate in uraemia, which is even exaggerated by dialysis initiation. In contrast, KTx markedly reduces AGEs and dicarbonyls. Given their associations with CVD risk in high-risk populations, lowering AGE and dicarbonyl levels may be valuable.
Uber happy? Work and well-being in the ‘Gig Economy’
Authors: Berger Thor , Frey Carl Benedikt , Levin Guy , Danda Santosh Rao 
Published: July 2019

SUMMARYWe study the rise of the so-called ‘gig economy’ through the lens of Uber and its drivers in the United Kingdom. Using administrative data from Uber and a new representative survey of London drivers, we explore their backgrounds, earnings, and subjective well-being. We find that the vast majority of Uber drivers are male immigrants, primarily drawn from the bottom half of the London income distribution. Most transitioned out of permanent part- or full-time jobs and about half of drivers’ report that their incomes increased after partnering with Uber. After covering vehicle operation costs and Uber’s service fee, we estimate that the median London driver earns about £11 per hour spent logged into the app. But while Uber drivers remain at the lower end of the London income distribution, they report higher levels of life satisfaction than other workers. Consistent with a trade-off between evaluative and emotional well-being observed among the self-employed, they also report higher anxiety levels. We hypothesize that the higher life satisfaction among Uber drivers partly reflects their preferences for flexibility and the autonomy that the platform offers. We provide suggestive evidence showing that drivers who emphasize flexibility as an important motivation to join Uber also report higher levels of subjective well-being. However, a minority of drivers who report that they would prefer work as an employee report lower levels of life satisfaction and higher levels of anxiety. Overall, our findings highlight the importance of non-monetary factors in shaping the welfare of workers in the gig economy.
Communication between primary and secondary care: deficits and danger
Authors: Dinsdale Elsa , Hannigan Ailish , O’Connor Ray , O’Doherty Jane , Glynn Liam , Casey Monica , Hayes Peter , Kelly Dervla , Cullen Walter , O’Regan Andrew 
Published: July 2019

Abstract

Background
Timely and accurate communication between primary and secondary care is essential for delivering high-quality patient care.

Objective
The aim of this study is to evaluate the content contained in both referral and response letters between primary and secondary care and measure this against the recommended national guidelines.

Methods
Using an observational design, senior medical students and their general practice supervisors applied practice management software to identify 100 randomly selected adults, aged greater than 50 years, from a generated list of consults over a 2-year period (2013–2015). All data included in referral and response letters for these adults were examined and compared with the gold standard templates that were informed by international guidelines.

Results
Data from 3293 referral letters and 2468 response letters from 68 general practices and 17 hospitals were analysed. The median time that had elapsed between a patient being referred and receiving a response letter was 4 weeks, ranging from 1 week for Emergency Department referral letters to 7 weeks for orthopaedic surgery referral letters. Referral letters included the reason for referral (98%), history of complaint (90%) and current medications (82%). Less commonly included were management prior to referral (65%) and medication allergies (57%). The majority of response letters included information on investigations (73%), results (70%) and follow-up plan (85%). Less commonly, response letters included medication changes (30%), medication lists (33%) and secondary diagnoses (13%).

Conclusions
Future research should be aimed at developing robust strategies to addressing communication gaps reported in this study.
An RNA-based quantitative and compositional study of ammonium-oxidizing bacteria and archaea in Lake Taihu, a eutrophic freshwater lake
Authors: Liu Tong-tong , Yang Hong 
Published: July 2019

ABSTRACTAmmonium-oxidizing archaea (AOA) and bacteria (AOB) play crucial roles in ammonium oxidation in freshwater lake sediment. However, previous reports on the predominance of AOA and AOB in the surface sediment of Lake Taihu have been based on DNA levels, detecting the total abundance of microbiota (including inactive cells), and have resulted in numerous contradictory conclusions. Existing RNA-level studies detecting active transcription are very limited. The current study, using RNA-based real-time quantification and clone library analysis, demonstrated that the amoA gene abundance of active AOB was higher than that of active AOA, despite conflicting results at the DNA level. Further exploration revealed a significant positive correlation between the potential nitrification rate (PNR) and the abundance of AOA and AOB at the RNA level, with irregular or contradictory correlation found at the DNA level. Ultimately, using quantitative analysis of RNA levels, we show AOB to be the active dominant contributor to ammonium oxidation. Our investigations also indicated that AOB were more diverse in high-ammonium lake regions, with Nitrosomonas being the active and dominating cluster, but that AOA had an advantage in the low-ammonium lake regions.
Opportunistic Infections Are More Prevalent in Crohn’s Disease and Ulcerative Colitis: A Large Population-Based Study
Authors: Sheriff Mohammed Zaahid , Mansoor Emad , Luther Jay , Ananthakrishnan Ashwin N , Abou Saleh Mohannad , Ho Edith , Briggs Farren B S , Dave Maneesh 
Published: July 2019

Abstract

Background
Opportunistic infections (OIs) are more common in patients with inflammatory bowel disease (IBD); however, there have been limited large-scale studies of OIs in IBD. We investigated the epidemiological characteristics of OI in Crohn’s disease (CD) and ulcerative colitis (UC) using a large population-based database.

Methods
Data were collected from a commercial database (Explorys Inc., Cleveland, OH, USA) that provided electronic health records from 26 major integrated US health care systems from 1999 to March 2018. In this data set, we identified all CD and UC patients, based on Systemized Nomenclature of Medicine–Clinical Terms. Within these cohorts, we identified a variety of OIs and compared the prevalence rate of OI in individuals with IBD with that of controls (patients in the database between March 2013 and March 2018 without the diagnosis of IBD).

Results
Explorys included 153,290 patients with CD and 128,540 patients with UC between March 2013 and March 2018. The prevalence of OIs was 17.8% in CD, 19.2% in UC, and 7% in non-IBD controls. When compared with non-IBD controls, all OIs were more common in CD (prevalence ratio [PR], 2.54; 95% confidence interval [CI], 2.51–2.57) and UC (PR, 2.74; 95% CI, 2.71–2.77). Overall, viral infections were numerically more common, whereas bacterial infections had the highest PRs in CD and UC when compared with controls without IBD.

Conclusions
We found significantly higher rates of OI in IBD. Our study suggests the need for close follow-up of IBD patients to diagnose and provide vaccinations where applicable for prevention of infections.