bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical and experimental simulation of a dynamic-rotational 3D cell culture for stratified living tissue models
Authors: Canadas Raphaël F , Liu Ziyu , Gasperini Luca , Fernandes Diogo C , Maia Fátima R , Reis Rui L , Marques Alexandra P , Liu Chaozong , Oliveira Joaquim M 
Published: February 2022

Abstract
Human tissues and organs are inherently heterogeneous, and their functionality is determined by the interplay between different cell types, their secondary architecture, and gradients of signalling molecules and metabolites. To mimic the dynamics of native tissues, perfusion bioreactors and microfluidic devices are widely used in tissue engineering (TE) applications for enhancing cell culture viability in the core of 3D constructs. Still, most in vitro screening methods for compound efficacy and toxicity assessment include cell or tissue exposure to constant and homogeneous compound concentrations over a defined testing period. Moreover, a prevalent issue inhibiting the large-scale adoption of microfluidics and bioreactor is the tubing dependence to induce a perfusion regime. Here, we propose a compartmentalized rotational (CR) 3D cell culture platform for a stable control over gradient tissue culture conditions. Using the CR bioreactor, adjacent lanes of constructs are patterned by controlled flow dynamics to enable tissue stratification. Numerical and experimental simulations demonstrate cell seeding dynamics, as well as culture media rotational perfusion and gradient formations. Additionally, the developed system induces vertical and horizontal rotations, which increase medium exchange and homogeneous construct maturation, allowing both perfused tubing-based and tubing-free approaches. As a proof-of-concept, experiments and accompanying simulation of cellular inoculation and growth in 3D scaffold and hydrogel were performed, before the examination of a blood-brain-barrier model, demonstrating the impact of a heterotypic culture on molecular permeability under mimetic dynamic conditions. Briefly, the present work discloses the simulation of 3D dynamic cultures, and a semi-automated platform for heterotypic tissues in vitro modelling, for broad TE and drug discovery/screening applications.
Enhanced fluorescence of CsPbBr3/ZnO heterojunction enabled by titanium nitride nanoparticles
Authors: Jiang Jinguo , Bai Zhongchen , Yao Heng , Qin Shuijie 
Published: February 2022

Abstract
We prepared CsPbBr3/ZnO heterojunctions by self-assembling colloidal CsPbBr3 quantum dots (QDs) on the surface of the ZnO film. The fluorescence of CsPbBr3/ZnO heterojunctions was modulated by titanium nitride nanoparticles (TiN NPs) to obtain highly photoluminescent CsPbBr3/TiN/ ZnO heterojunctions. The results showed that when the TiN thickness was 51 nm, the fluorescence of the CsPbBr3/TiN/ZnO heterojunction was enhanced by 3.2 times compared to that of the CsPbBr3/ZnO heterojunction. TiN NPs combined most of the photo-generated electrons with the holes on the surface of the TiN/CsPbBr3 heterojunction, which increased the electron transfer rate and reduced non-radiative recombination. This method of enhancing heterojunction fluorescence could provide a new pathway for photovoltaic, light-emitting diode (LED), photodetector, light sensor, and image sensor applications.
Compatibilization, processing and characterization of poly(butylene adipate terephthalate)/polylactide (PBAT/PLA) blends
Authors: Su Shen 
Published: February 2022

Abstract
A blend of poly(butylene adipate terephthalate) (PBAT) and polylactide (PLA) is a combination of biodegradable materials. This study aims to prepare compatibilized PBAT/PLA in a cost-effective and timesaving way and to process the material into blown films by fine-tuning the processing parameters. First, a catalyst masterbatch is prepared by transesterification of PBAT and PLA in the presence of tetrabutyl titanate (TBT) as a catalyst. This is followed by the compounding of the two polymer types in combination with the catalyst masterbatch. Third, the compounds are processed into blown films and panels. The processing parameters for film blowing are set to reduce the anisotropy. Finally, the material properties are evaluated such as mechanical tests. The fine-tuning of parameter settings including the blow-up ratio and draw-down ratio results in a higher degree of isotropy of the blown film. By adding the catalyst masterbatch (2 wt%, which corresponds to TBT of approximately 0.002 wt% with copolymers formed) in combination with the fine-tuning of parameter settings, the samples achieved a significant improvement on the material properties. The morphology of the cryogenically fractured panel samples shows a decrease in the diameter of the dispersed phase. In the cross and machine directions, the elongation at break increased by 85 and 93%, and the trouser tear propagation resistance increased by 2.4 and 10 N mm−1, respectively. Furthermore, both the elongation at break and the trouser tear propagation of the blown films achieved a higher degree of isotropy.
Tropical floor plans and enumeration of complex and real multi-nodal surfaces
Authors: Markwig Hannah , Markwig Thomas , Shaw Kris , Shustin Eugenii 
Published: February 2022

The family of complex projective surfaces in

P

3

\mathbb {P}^3

of degree

d
d

having precisely

δ
\delta

nodes as their only singularities has codimension

δ
\delta

in the linear system

|

O

P

3

(
d
)

|

|{\mathcal O}_{\mathbb {P}^3}(d)|

for sufficiently large

d
d

and is of degree

N

δ
,

C

P

3

(
d
)
=
(
4
(
d
−
1

)
3

)
δ

/

δ
!
+
O
(

d

3
δ
−
3

)

N_{\delta ,\mathbb {C}}^{\mathbb {P}^3}(d)=(4(d-1)^3)^\delta /\delta !+O(d^{3\delta -3})

. In particular,

N

δ
,

C

P

3

(
d
)

N_{\delta ,\mathbb {C}}^{\mathbb {P}^3}(d)

is polynomial in

d
d

.

By means of tropical geometry, we explicitly describe

(
4

d
3

)
δ

/

δ
!
+
O
(

d

3
δ
−
1

)

(4d^3)^\delta /\delta !+O(d^{3\delta -1})

surfaces passing through a suitable generic configuration of

n
=

(

d
+
3

3

)

−
δ
−
1

n=\binom {d+3}{3}-\delta -1

points in

P

3

\mathbb {P}^3

. These surfaces are close to tropical limits which we characterize combinatorially, introducing the concept of floor plans for multinodal tropical surfaces. The concept of floor plans is similar to the well-known floor diagrams (a combinatorial tool for tropical curve counts): with it, we keep the combinatorial essentials of a multinodal tropical surface

S
S

which are sufficient to reconstruct

S
S

.

In the real case, we estimate the range for possible numbers of real multi-nodal surfaces satisfying point conditions. We show that, for a special configuration

w
\boldsymbol {w}

of real points, the number

N

δ
,

R

P

3

(
d
,
w
)

N_{\delta ,\mathbb {R}}^{\mathbb {P}^3}(d,\boldsymbol {w})

of real surfaces of degree

d
d

having

δ
\delta

real nodes and passing through

w
\boldsymbol {w}

is bounded from below by

(

3
2

d
3

)

δ

/

δ
!
+
O
(

d

3
δ
−
1

)

\left (\frac {3}{2}d^3\right )^\delta /\delta ! +O(d^{3\delta -1})

.

We prove analogous statements for counts of multinodal surfaces in

P

1

×

P

2

\mathbb {P}^1\times \mathbb {P}^2

and

P

1

×

P

1

×

P

1

\mathbb {P}^1\times \mathbb {P}^1\times \mathbb {P}^1

.
Wartime Dollars and the Crowning of China’s Hog Bristle King
Authors: Kinzley Judd 
Published: February 2022

Abstract
US war mobilization efforts in the early 1940s helped create demand for a vast assortment of raw materials not produced in the domestic United States. These demands led to the formation of a new foreign aid regime that sought to procure strategic materials in exchange for loans, cash, and industrial and military goods. This essay, which draws on archival sources collected in China, Taiwan, and the United States, examines the power and legacy of US overseas procurement programs by focusing on the case of China and the US effort to acquire hog bristles. Hog bristles, which were used for the production of a vast assortment of brushes, were one of China’s largest wartime exports. The US wartime demand for bristles helped empower a small number of Chinese firms that controlled local production. One of these firms used wartime controls to dominate the industry by 1945, and the head of the firm, Gu Gengyu, was later deemed the “hog-bristle king.” This essay explores the long-term legacies of US wartime procurement programs, revealing how they helped empower a new and powerful class of transnational businessmen with strong ties to the government, as well as deep connections to US markets.
“That City Af loat”
Authors: McMahon Cian T 
Published: February 2022

Abstract
Throughout the eighteenth and nineteenth centuries, millions of migrants from every corner of the earth spent weeks and sometimes months at sea. Yet these ubiquitous voyages appear as little more than blank pages in the annals of human migration. Maritime social history has grown considerably over the past thirty years, offering brilliant new insights into the lived experiences of sailors, pirates, and slaves. But the lowly emigrant has been largely ignored. At the same time, scholars carefully tracing the development of migrant communities at the local, national, and transnational levels have tended to reify the historiography’s traditional terracentrism. Using the letters, diaries, and printed guides of those who left Ireland during the Great Famine, this article seeks to understand how the journey itself shaped community building in the Irish diaspora. It argues that the hardships of life at sea encouraged disparate groups of people to expand their traditional ideas of belonging. Localism and ethnic identity did not dissolve at sea, they changed—making room for new and heterogeneous links of solidarity anchored in shared experience.
Taking the Temperature: An Intersectional Examination of Diversity Acceptance in Canadian Police Services
Authors: Bikos Lesley J 
Published: February 2022

AbstractThis exploratory study analyses data from in-depth interviews (116 from 31 police services across Canada) and an online survey (N = 727) to examine how gender and racial ideologies inform ongoing cultural and structural adherence to hegemonic whiteness and masculinity, impacting who has power (and who does not) within the institution of policing. White, cisgender, heterosexual men were the most likely to present views consistent with white supremacist patriarchy. Their ongoing cultural, structural, and material power created gatekeeping conditions that are at least part of the explanation for barriers to the recruitment and promotion of racialized women, men, and white women. Findings also reveal that a significant proportion of white women and some racialized men also upheld these ideologies, indicating cultural-level buy-in. There were disrupters who attempted to influence cultural and structural change, but barriers and resistance at leadership levels remain. Thus, this study adds to the growing body of evidence that diversity representation alone has not, and will not, transform the institution in a timely and meaningful way.
Affinity and the classroom: informal and formal L2 learning
Authors: Brevik Lisbeth M , Holm Thea 
Published: February 2022

Abstract
Connecting informal and formal language teaching and learning has gained prominence as a way to understand language development among teenagers, but questions remain regarding its application in L2 contexts. This study investigates the significance of such connections in two L2 English classes taught by the same teacher, where students were learning English during a technology-based project, the Time Traveller. We collected data during three weeks of fieldwork at a Norwegian secondary school. We found that informal and formal language teaching and learning were connected in two ways: the students’ use of English outside school was primarily linked to online game play and social media, and the teacher was able to design activities that extended her students’ existing affinity space, resulting in the students using English in the classroom more frequently and more confidently than before. Implications include the importance of understanding students’ informal language learning to rethink L2 teaching practices.
Reconstruction of Nitrogenase Predecessors Suggests Origin from Maturase-Like Proteins
Authors: Garcia Amanda K , Kolaczkowski Bryan , Kaçar Betül 
Published: February 2022

AbstractThe evolution of biological nitrogen fixation, uniquely catalyzed by nitrogenase enzymes, has been one of the most consequential biogeochemical innovations over life’s history. Though understanding the early evolution of nitrogen fixation has been a longstanding goal from molecular, biogeochemical, and planetary perspectives, its origins remain enigmatic. In this study, we reconstructed the evolutionary histories of nitrogenases, as well as homologous maturase proteins that participate in the assembly of the nitrogenase active-site cofactor but are not able to fix nitrogen. We combined phylogenetic and ancestral sequence inference with an analysis of predicted functionally divergent sites between nitrogenases and maturases to infer the nitrogen-fixing capabilities of their shared ancestors. Our results provide phylogenetic constraints to the emergence of nitrogen fixation and are consistent with a model wherein nitrogenases emerged from maturase-like predecessors. Though the precise functional role of such a predecessor protein remains speculative, our results highlight evolutionary contingency as a significant factor shaping the evolution of a biogeochemically essential enzyme.
Lysosomal ceramides regulate cathepsin B-mediated processing of saposin C and glucocerebrosidase activity
Authors: Kim Myung Jong , Jeong Hyunkyung , Krainc Dimitri 
Published: February 2022

Abstract
Variants in multiple lysosomal enzymes increase Parkinson’s disease (PD) risk, including the genes encoding glucocerebrosidase (GCase), acid sphingomyelinase (ASMase) and galactosylceramidase. Each of these enzymes generates ceramide by hydrolysis of sphingolipids in lysosomes, but the role of this common pathway in PD pathogenesis has not yet been explored. Variations in GBA1, the gene encoding GCase, are the most common genetic risk factor for PD. The lysosomal enzyme cathepsin B has recently been implicated as an important genetic modifier of disease penetrance in individuals harboring GBA1 variants, suggesting a mechanistic link between these enzymes. Here, we found that ceramide activates cathepsin B, and identified a novel role for cathepsin B in mediating prosaposin cleavage to form saposin C, the lysosomal coactivator of GCase. Interestingly, this pathway was disrupted in Parkin-linked PD models, and upon treatment with inhibitor of ASMase which resulted in decreased ceramide production. Conversely, increasing ceramide production by inhibiting acid ceramidase activity was sufficient to upregulate cathepsin B- and saposin C-mediated activation of GCase. These results highlight a mechanistic link between ceramide and cathepsin B in regulating GCase activity and suggest that targeting lysosomal ceramide or cathepsin B represents an important therapeutic strategy for activating GCase in PD and related disorders.
P27 Bacterial coinfection and antibiotic stewardship in patients with COVID-19: a systematic review and meta-analysis
Authors: Calderon Maria , Gysin Grace , Walpole Sarah , Mills Felicity , Comandé Daniel , Hunter Ewan 
Published: February 2022

Abstract

Introduction
Understanding the proportion of patients with COVID-19 who have respiratory bacterial coinfections and the responsible pathogens is important to managing COVID-19 effectively while ensuring responsible antibiotic use.

Objectives
To estimate the frequency of bacterial coinfection in COVID-19 patients and of antibiotic prescribing and to appraise the use of antibiotic stewardship criteria.

Methods
Systematic review and meta-analysis was performed using major databases up to May 15, 2020. We included studies that reported a) proportion/prevalence of bacterial coinfection in COVID-19 patients and b) use of antibiotics. Where available, data on duration and type of antibiotics, adverse events, and any information about antibiotic stewardship policies were also collected.

Results
We included 39 studies with a total of 10 815 patients. The overall prevalence of bacterial coinfection was 10.6% (95% CI 6.8%–14.3%). When only confirmed bacterial coinfections were included the prevalence was 4.6% (95% CI 2.9%–7%). Thirty-five bacterial species were identified, the most frequent being Mycoplasma pneumoniae (n = 12 [34%]), Pseudomonas aeruginosa (n = 4 [11.4%]) and Legionella pneumophila (n = 2 [6%]). The overall antibiotic use was 71.3% (95% CI 63.1%–79.5%). Only one study described criteria for stopping them. All included studies had a moderate to high risk of bias.

Conclusions
There is currently insufficient evidence to support widespread empirical use of antibiotics in most hospitalized patients with COVID-19, as the overall proportion of bacterial coinfection is low. Furthermore, as the use of antibiotics appears currently to be largely empirical, it is necessary to formulate clinical guidelines to promote and support more targeted administration of antibiotics in patients admitted to hospital with COVID-19.
P34 Impact of medical microbiology lead antimicrobial stewardship rounds on antimicrobial consumption in a level 3 hospital
Authors: Lucey Mary , O’Regan Sabrina , Waldron Ruth 
Published: February 2022

Abstract

Background
No onsite consultant medical microbiologist (CMM) was available in this centre from September 2018 to November 2019. During this time antimicrobial stewardship (AMS) rounds were carried out by the antimicrobial pharmacist (AMP) with feedback provided directly to clinical teams. Antimicrobial consumption rose from 88.81 DDD/bed-days used (DDD/BDU) in 2017 to 95.57 DDD/BDU in 2019. The aim of this study was to assess the impact of AMS service led by a CMM.

Methods
A structured antimicrobial stewardship programme has been in place since 2013. The re-addition of an onsite CMM in November 2019 facilitated new AMS initiatives, including ward based, targeted antimicrobial rounds, team audits and education sessions led by the CMM. These rounds focused on the choice of antimicrobial agent and duration of therapy.

Results
Overall antimicrobial consumption decreased from 95.57 DDD/BDU in 2019 to 82.16 DDD/BDU (14% reduction) in 2020. The addition of team-based AMS rounds with a CMM and AMP alongside the clinical team enhanced the existing AMS programme and appeared to have the most benefit in reducing antimicrobial consumption. Increases in consumption were noted during weeks where there was poor attendance or cancellation of the AMS rounds.

Conclusions
AMS is most effective with specialty leadership and a multidisciplinary approach. Continuous intervention is required in order to sustain improvements. AMS programmes have been shown to reduce the incidence of healthcare-associated infection and have a positive impact on antimicrobial resistance. AMS should be prioritized by healthcare institutions for increased investment.
P36 Procalcitonin as an antimicrobial stewardship tool in the COVID-19 era: a single centre experience
Authors: Creedon Margaret , Talento Alida Fe , Connolly Roisin , Egan Aine , Hassan Tidi , Trzos-Grzybowksa Marta 
Published: February 2022

Abstract

Background
Procalcitonin (PCT) is a biomarker which may have greater specificity than other pro-inflammatory markers in identifying bacterial infection and may aid in antimicrobial stewardship in COVID-19 patients.

Methods
A PCT assay by Abbott diagnostics was introduced in our hospital in November 2020. Over a 12 week period, we prospectively recorded all PCT results on in-patients with COVID-19 admitted to the ICU, as well as stewardship actions taken following discussion with the ICU physicians. Microbiology records were reviewed to ascertain whether bacterial infection was subsequently confirmed.

Results
Sixty-four PCT results were recorded on 27 patients (Table 1). Antimicrobials were discontinued on 12 occasions and withheld on 16 occasions where PCT was &lt;0.5 ng/mL. No cases of confirmed bacterial infection were diagnosed in patients with PCT concentrations of &lt;0.05 ng/mL; however definite bacterial infection was confirmed in two patients (one case of Staphylococcus aureus bloodstream infection; one case of Staphylococcus epidermidis CVC infection), and bacterial infection was designated probable in five patients with PCT ≥0.05 ng/mL and &lt;0.5 ng/mL.

Conclusions
PCT may be a useful tool in enabling antimicrobial stewardship actions in patients with severe COVID-19, but results need to be interpreted within the clinical context.
P39 Bloodstream infections (BSI) in tertiary ICU—an update!
Authors: Patel Veer M. , Desai Seema 
Published: February 2022

Abstract

Background
Patients in ICU represent a small proportion of inpatients; however they account for up to 25% of all hospital acquired infections (HAI) and are 2–5 times more likely to develop a HAI than the average patient. Management of bloodstream infections (BSI) in ICU is a rising problem due to increasing antibiotic resistance posing challenges to antimicrobial stewardship (AMS) leading to higher mortality in ITU patients. It increases duration of inpatient stay, hospital costs and worsens prognosis.

Objectives
To find all-cause mortality in patients with BSI admitted to intensive care at 14 and 28 days from admission.

Methods
We used retrospective patient data from the hospital database between March 2019 to March 2020.

Results
We included 113 patients admitted to ICU and had BSI, of which 12.4% died at 14 days and 24.8% died at 28 days with overall mortality of 33.6% at discharge. Respiratory comorbidity was found significantly higher (48.1%). Patients with Gram-negative BSI had higher mortality with 14.29% at 14 days when compared with Gram-positive BSI, but 28 day mortality was similar in both groups (25.71% and 25% respectively), which is concerning.

Conclusions
This study concludes that patients admitted to ICU have higher mortality at 28 days irrespective of the pathogen isolated in the bloodstream. This could be explained due to prolonged stay in ICU leading to increased burden from HAI. Future AMS will have to focus on a prevention model for this cohort to improve patient outcome.