bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship among Locus of Control, Academic Interest and Secondary School Students Academic Achievement in Anambra State, Nigeria
Authors: Akunne L. I. , Anyanmene A. N.
Published: March 2021

Aims: To determine the relationship between locus of control and academic achievement in English language, the relationship between academic interest and academic achievement in English language, the relationship between locus of control and academic achievement in Mathematics, the relationship between academic interest and academic achievement in Mathematics.

Study Design: The study adopted the correlational survey design

Place and Duration of Study: Secondary schools in Anambra state, Nigeria.

Methodology: Disproportionate stratified sampling technique was used to select a sample size of 2,160 students from a population of 18,297 SS2 students in Anambra state government owned secondary schools. The instruments adopted for data collection were standardized locus of control scale, student’s academic interest scale, these instruments were administered using the direct delivery approach. Data collected were tested using Pearson Product Moment Correlation Coefficient, while the hypotheses postulated was tested at 0.05 level of significance using t-test of correlation and multiple regression analysis.

Results: the relationship between locus of control and academic achievement of secondary school students in English language is moderate and positive (r = 0.469/n = 2050), the relationship between academic interest and academic achievement of secondary school students in English language is high and positive (r = 0.731, n = 2050), the relationship between locus of control and academic achievement of secondary school students in Mathematics is high and positive (r = 0.613, n = 2050). The relationship between locus of control and academic achievement of secondary school students in English language is significant (t-cal. = 24.03 > t-cal. 1.960), the relationship between academic interest and academic achievement of secondary school students in English language is significant (t – cal. = 48.46 < t – crit. = 1.960), the relationship between locus of control and academic achievement in Mathematics is significant (t-cal. = 35.12 > t-crit. = 1.960), the relationship between academic interest and academic achievement of secondary school students in Mathematics is statistically significant (t-cal. = 28.32 > t-crit. = 1.960).

Conclusion: locus of control and academic interest are variables associated with academic achievement of secondary school students in Anambra state. Nevertheless, secondary school students spend significant part of their time in the classroom (about 7 ½ hrs a day, 5 days a week, and 36 weeks a year) with teachers and peers, there is need to help them understand their locus of control, improve their interest in learning as well as develop belief in themselves to succeed academically.
Increasing Challenges of Potable Water Supply and Its Implications on the Population of Buea Municipality, Cameroon
Authors: Buh Emmanuel Nong , Mbua Roy Lyonga , Zeh Amos Fang
Published: March 2021

The increasing challenges of potable water supply on the population of Buea municipality, Camerooon, if not monitored and effectively managed by government and all the local communities (stake holders) will be very detrimental to the municipality. The water demand of the growing population of Municipality is supplied by CAMWATER (Cameroon Water Utilities Corporation) and the local communities involved in potable water management. This study employed the use of a purposive systematic random sampling technique and focus group discussion among the community dwellers to evaluate the implications of potable water scarcity. A total of 350 questionnaires were administered in the field, interviews were conducted with water supply authorities and various stake holders in the municipality to identify the major problems faced by the inhabitants of Buea as a result of potable water supply challenges. Results revealed that about 27% of the population of Buea faces frequent water shortages, 32% and 41% of the respondents stated that the main causes of water supply challenges are poor management of potable water by the authorities concerned and over exploitation of water sources by the increasing population respectively. Besides the human factors mentioned above, changing climatic conditions worsen these challenges. In conclusion, over exploitation of potable water sources by the population and poor management by the authorities concerned stands as a major driver of the challenges of water scarcity in the Buea municipality. As such, we recommend an integrated water management approach as a means of making potable water supply challenges less problematic to the population of Buea.
Determining the Maximum Rate of Potassium Fertilizer on Oil Palm (Elaeis guineensis Jacq.) in Production in Southeastern Côte d'Ivoire
Authors: Konan Kouame , Jean–Martial Kassi Koffi Fernand , Boaké Kone
Published: March 2021

In the southeastern of Côte d'Ivoire, ferralsols are characterized by poverty in exchangeable bases, especially potassium, which appears to be the predominant mineral element for oil palm cultivation.   In this study, we used improved palm cultivars treated with different rates of potassium fertilizer to determin the effect on oil palms. The experiments were conducted on the CNRA station in La Mé and PALMCI in Ehania (Côte d’Ivoire), following a system block system design comprising of five treatments and four repetitions. Treatments included 5 rates of potassium fertilizer (T1, T2, T3, T4, T5) corresponding to 1; 1.5; 2; 2.5; 3 kg of KCl/tree/year. This study indicates that the different rates of KCl applied, had influence on    all of the experimental parameters, namely: yields (TR) and its components (NR; PR and PMR). Yields on the Ehania plantation were significantly higher than those on La Mé. Yield ranged from 18.8 Tons/ha/year (T1) to 22.1 Tons/ha/year (T3) in La Mé, and from 21.2 to 25.6 tons/ha/year in Ehania. The theoretical maximum rates were 2.4 kg of KCl/tree/year in La Mé, compared to 1.9 kg/tree/year on the Ehania plantation. Therefore, these rates will be used in the future extension of potassium fertilizer, in the cultivation of oil palm, in the southeastern of Côte d'Ivoire.
Frequency of Various Causes of Hospitalization and Its Other Related Factors in Patients with Heart Failure
Authors: Jafarie Hamid Reza , Zare Elahe , Shafiee Mohammad
Published: March 2021

Background: Heart failure has the highest rate of Rehospitalization with 20-33% readmissions within 1 to 3 months of discharge from the hospital. we decided to find out the frequency of different causes of hospitalization in patients with heart failure during 2017 to 2019.

Methods: This study was a cross-sectional descriptive study. A total of 120 patients with heart failure who were referred to Afshar Hospital of Yazd during 2017 to 2019 were enrolled. The random sampling method was used.The required information was collected from heart failure patients’ registry project. datum were collected and were analyzed by statistical tests and SPSS version 18.

Results: The mean age of patients was 53.53±12.36 years. Of the 120 patients under study,41.7% were women and 58.3% were male. The results showed that, 14.2% did not follow the recommended diet,14.2% had not regular use of drugs,14.2% had renal dysfunction,9.2% had miscellaneous causes,8.3% had pulmonary disease and 40% had idiopathic cause(where the cause of the condition is not known). There was no significant difference among the distribution of various causes of hospitalization in terms of the variables in the study.

Conclusions: It can be concluded that the most common reason for hospitalization of patients with heart failure is idiopathic cause.
Application of Fuzzy DEMATEL Method on the Impact of IT innovation on Supply Chain Management of Food Industry in Nigeria
Authors: Boye Ayantoyinbo Benedict
Published: March 2021

Supply chain management can be viewed as an important part of a company's strategic strategy for increasing efficiency, results, and profitability. The aim of this paper is to us the fuzzy DEMATEL method to examine the impact of IT innovation on the operations of supply chain management of food industry in Nigeria. The study obtained sixteen (16) perspectives of impact of IT innovation on food industry SC management as obtain from literature and brain stormy of experts. A fuzzy Linguistic scale was developed and applies it to food manufacturing firms in Nigeria to test the level of the impact of IT innovation on supply chain management. The questionnaire designed for pairwise comparison to evaluate the influence of each score, where scores of 0, 1, 2, 3 and 4 represent: (no influence), (Very low influence), (low influence), (high influence) and (very high influence), respectively. Twelve experts were asked to complete the questionnaire comprises of 6 general managers, 6 Supply Chain managers all of food industry. Then the Fuzzy DEMATEL method was applied to analyze the importance of criteria and the casual relations among the criteria constructed. The result showed that the advanced planning system had the most impact and the strongest link to other criteria. As a result, APS is a key rationale and key criteria that influence other criteria and driving factors to solve problems.
Spirochaetes
Authors: Wang Guiqing
Published: March 2021

Microorganisms in the phylum Spirochaetes are thin, spiral‐shaped or wavelike and highly motile bacteria that are best visualised by darkfield microscopy. Spirochaetes are Gram‐negative‐like, in that they possess inner and outer membranes separated by a peptidoglycan‐containing periplasmic space. Beyond these ultrastructural similarities, few parallels exist with conventional Gram‐negative bacteria. The current taxonomy of spirochaetes consists of five families with at least 23 genera and ∼150 validly published species, including the well‐known pathogenic, disease‐causing species
Treponema pallidum
(syphilis),
Leptospira
sp. (leptospirosis) and
Borrelia burgdorferi
(Lyme disease). The phylogenetic relationship among spirochaetes is evident at the level of gross phenotypic characteristics, which include a distinctive morphology derived from the presence of periplasmic flagella. The updated taxonomy, genomic, physiological, structural and functional features make Spirochaetes unique among the prokaryotes.

Key Concepts

Spirochaetes are a genetically and morphologically distinct group of bacteria.

Spirochaetes are thin, spiral‐shaped or wavelike bacteria that are highly motile.

Endoflagella/periplasmic flagella provide spirochaetes with their characteristic morphology and motility.

Spirochaetes differ from typical Gram‐negative bacteria at the ultrastructural level.

Spirochaetes are chemoorganotrophic, grow in diverse conditions and are composed of both pathogenic and nonpathogenic members.

Complete genome sequencing has allowed for the characterisation and differentiation of spirochaetes at the genetic level.

Medically important spirochaetes belong to the three genera
Borrelia
,
Leptospira
and
Treponema
.
Chemoattraction: Basic Concepts and Role in the Immune Response
Authors: Rodríguez‐Fernández José Luis , Criado‐García Olga
Published: March 2021

In leucocytes, chemoattraction involves the detection of the direction of a chemical gradient of chemoattractants, a process called chemoattractant gradient sensing, followed by their migration towards the chemoattractant. Chemoattraction is called ‘chemotaxis’ when the chemoattractant gradient is soluble and ‘haptotaxis’ when this gradient is bound to the substrate. Chemoattraction plays a fundamental role in the regulation of the precise location of leucocytes during the immune response and consequently is fundamental for the adequate functioning of leucocytes in the immune system. Classical chemoattractants and chemokines use guanine nucleotide‐binding protein (G‐protein)‐coupled seven‐transmembrane‐spanning receptors (GPCRs) to relay intracellular signals that regulate chemoattraction. Apart from chemoattraction, chemoattractant receptors regulate additional functions in leucocytes that could also contribute to a correct immune response.

Key Concepts

Chemoattraction is defined as the orientation of a cell in the direction of a chemical gradient of ligands followed by the migration of the cells towards the chemoattractant.

Chemoattractive factors are a diverse group of chemicals, including lipids, formylated peptides, proteolytic fragments of complement proteins and chemokines, with chemoattractive properties.

Chemokines are small secreted proteins (8–14 kDa), which display a similar tertiary structure and potent chemoattractive abilities.

Chemoattraction is regulated by chemoattractant receptors that are largely members of the G‐protein receptor‐coupled (GPCR) superfamily.

GPCR chemoattractant members largely use Gi family proteins to regulate chemoattraction and other functions, although other G protein families can also be used.

Chemoattractant receptors regulate not only chemoattraction but also a variety of additional functions in cells.

Chemoattractant receptors are functionally divided into homeostatic receptors, which regulate homeostatic (e.g. chemotaxis, survival, migratory speed, cell shape changes and endocytosis) functions of cells, and inflammatory receptors, which control both homeostatic and inflammatory activities (e.g. generation of ROS, secretion of proteases, secretion of inflammatory cytokines and chemokines and formation of neutrophil extracellular trap (NET)).
Transfer RNA Recognition and Aminoacylation by Synthetases
Authors: Giegé Richard , Eriani Gilbert
Published: March 2021

Fidelity of transfer ribonucleic acid (tRNA) charging by amino acids ensures correct translation of the genetic code into proteins. Charging is catalysed by a set of enzymes known as aminoacyl‐tRNA synthetases. Owing to the degeneracy of the genetic code, some of the different tRNAs have the same amino acids attached to them. Specificity of charging obeys universal rules and is ensured by positive elements, the identity determinants unique to each tRNA and responsible for its recognition by the cognate synthetase, and negative elements, the antideterminants that prevent false recognitions. To fulfil the aminoacylation specificity and prevent noncognate aminoacyl‐tRNA delivery to the ribosome, some synthetases also mediate proofreading reactions that increase fidelity of the tRNA charging. In such reactions, misactivated amino acids or mischarged tRNAs are checked in specific sites, and noncognate products are hydrolysed. However, mischarging is beneficial under certain stress circumstances or when catalysed by nondiscriminatory synthetases and represents a driving force in evolution.

Key Concepts

Translational expression of the genetic code refers to aminoacyl‐tRNA‐ and ribosome‐dependent decoding of genes into proteins, a process highly dependent on fidelity of tRNA aminoacylation by synthetases.

The rules that account for the aminoacylation identity of tRNAs are referred to as the second genetic code.

The RNA operational code is encoded in the acceptor stem of tRNA and is crucial for recognition by aminoacyl‐tRNA synthetases and specific aminoacylation.

Allostery in tRNA–synthetase systems concerns long‐range transfer of chemical information (up to 75 Å) to the synthetase catalytic site (through the body of tRNA and/or synthetase) triggered by contacts of tRNA identity determinants with the synthetase.

Engineering the identity of tRNA–synthetase systems allows reprogramming the genetic code.
Sauria (Lizards)
Authors: Benton Michael J
Published: March 2021

Lizards are generally small fast‐moving four‐legged slender terrestrial animals. The group of 6880 species of lizards, however, contains some exceptions: the large predatory Komodo dragon, the marine Galapagos iguana, the glidingDraco, various limbless forms and burrowers.

Key Concepts

Lizards are a large part of the Squamata, the clade comprising lizards, snakes and amphisbaenians.

There are some 6880 species of lizards today.

Lizards range in size from tiny geckos and chameleons only 2–3‐cm long to the Komodo monitor up to 2.6‐m long.

Lizards have kinetic skulls with three extra joints, so they can open their mouth extra wide while feeding.

Squamates fall into six major groups – the geckos, skinks, iguanas, anguimorphs (anguids, varanids), amphisbaenians and snakes.

Lizards are all ectothermic, controlling their body temperatures by behavioural means.

Lizards live mainly in tropical areas.

The fossil history of lizards shows that they evolved in the Triassic and became more diverse in the Jurassic and Cretaceous. The Late Cretaceous mosasaurs were the largest lizards of all, marine predators that reached 3–10 m in length.
Evolutionary Ideas: The Eclipse of Darwinism
Authors: Bowler Peter J
Published: March 2021

Following the acceptance of evolutionism, biologists tried – with limited success – to reconstruct the history of life on Earth and also debated the mechanism of evolution. Many alternatives to Darwinian natural selection were tried out, including a revived version of Lamarck's theory of the inheritance of acquired characters and evolution by saltations (which paved the way for Mendelian genetics).
Rhodosalinus
Authors: Guo Ling‐Yun , Du Zong‐Jun
Published: March 2021

Rho.do.sa.li'nus. Gr. neut. n.
rhodon
, the rose; L. masc. adj.
salinus
, saline; N.L. masc. n.
Rhodosalinus
, the red‐colored bacterium isolated from saline.

Proteobacteria / Alphaproteobacteria / Rhodobacterales / Rhodobacteraceae / Rhodosalinus

The genus
Rhodosalinus
contains moderately halophilic, facultatively anaerobic, and mesophilic bacteria. It currently includes two species,
Rhodosalinus sediminis
and
Rhodosalinus halophilus
, both isolated from marine salterns. Cells are Gram‐stain‐negative, motile, non‐spore‐forming, and rod shaped. Colonies of
Rhodosalinus
are circular and red or beige. The genomes of the
Rhodosalinus
species have a high G + C content, from 69.8% (genome sequencing) to 70.9% (HPLC). The sole respiratory ubiquinone is Q‐10. The major polar lipid profile contains phosphatidylglycerol, unidentified glycolipid, unidentified lipids, and unidentified phospholipids. The major fatty acids are C
18:1
ω7
c
, cyclo C
19:0
ω8
c
, and C
18:0
.

DNA G + C content (mol%)
: 69.8–70.9.

Type species
:
Rhodosalinus sediminis
Guo et al. 2017
VP
.
Eggerthellales
Authors: Gupta Radhey S.
Published: March 2021

Eg.ger.thel.la'les. N.L. fem. n.
Eggerthella
, type genus of the order; suff. ‐
ales
, ending to denote an order; N.L. fem. pl. n.
Eggerthellales
, the order of
Eggerthella
.

Actinobacteria / Coriobacteriia / Eggerthellales

The order contains the family
Eggerthellaceae
. The characteristics of this order are the same as that of the family
Eggerthellaceae
. The species of this order form a distinct clade in phylogenetic trees based on the concatenated sequences of different datasets of proteins. Additionally, the members of this order can be reliably distinguished from those of the order
Coriobacteriales
and other
Actinobacteria
, based on multiple molecular markers in the forms of conserved signature inserts/deletions in proteins that are exclusively present in the members of this order.

Type genus
:
Eggerthella
Wade et al. 1999
VP
.
On the reduction of aperture complexity in kidney SABR
Authors: Gaudreault Mathieu , Offer Keith , Kron Tomas , Siva Shankar , Hardcastle Nicholas
Published: March 2021

Background

Stereotactic ablative body radiotherapy (SABR) of primary kidney cancers is confounded by motion. There is a risk of interplay effect if the dose is delivered using volumetric modulated arc therapy (VMAT) and flattening filter‐free (FFF) dose rates due to target and linac motion. This study aims to provide an efficient way to generate plans with minimal aperture complexity.

Methods

In this retrospective study, 62 patients who received kidney SABR were reviewed. For each patient, two plans were created using internal target volume based motion management, on the average intensity projection of a four‐dimensional CT. In the first plan, optimization was performed using a knowledge‐based planning model based on delivered clinical plans in our institution. In the second plan, the optimization was repeated, with a maximum monitor unit (MU) objective applied in the optimization. Dose‐volume, conformity, and complexity metric (with the field edge metric and the modulation complexity score) were compared between the two plans. Results are shown in terms of median (first quartile — third quartile).

Results

Similar dosimetry was obtained with and without the utilization of an objective on the MU. However, complexity was reduced by using the objective on the MUs (modulation complexity score = 0.55 (0.50–0.61) / 0.33 (0.29–0.36), P‐value < 10−10, with/without the MU objective). Reduction of complexity was driven by a larger aperture area (area aperture variability = 0.68 (0.64–0.73) / 0.42 (0.37–0.45), P‐value < 10−10, with/without the MU objective). Using the objective on the MUs resulted in a more spherical dose distribution (sphericity 50% isodose = 0.73 (0.69–0.75) / 0.64 (0.60–0.68), P‐value < 10−8, with/without the MU objective) reducing dose to organs at risk given respiratory motion.

Conclusions

Aperture complexity is reduced in kidney SABR by using an objective on the MU delivery with VMAT and FFF dose rate.
Commissioning cranial single‐isocenter multi‐target radiosurgery for the Versa HD
Authors: Knill Cory , Sandhu Raminder , Halford Robert , Snyder Michael , Seymour Zachary
Published: March 2021

Purpose

Brainlab’s Elements Multiple Brain Mets SRS (MBMS) is a dedicated treatment planning system for single‐isocenter multi‐target (SIMT) cranial stereotactic radiosurgery (SRS) treatments. The purpose of this study is to present the commissioning experience of MBMS on an Elekta Versa HD.

Methods

MBMS was commissioned for 6 X, 6 FFF, and 10 FFF. Beam data collected included: output factors, percent depth doses (PDDs), diagonal profiles, collimator transmission, and penumbra. Beam data were processed by Brainlab and resulting parameters were entered into the planning system to generate the beam model. Beam model accuracy was verified for simple fields. MBMS plans were created on previously treated cranial SRS patient data sets. Plans were evaluated using Paddick inverse conformity (ICI), gradient indices (GI), and cumulative volume of brain receiving 12 Gy. Dosimetric accuracy of the MBMS plans was verified using microDiamond, Gafchromic film, and SRS Mapcheck measurements of absolute dose and dose profiles for individual targets. Finally, an end‐to‐end (E2E) test was performed with a MR‐CT compatible phantom to validate the accuracy of the simulation‐to‐delivery process.

Results

For square fields, calculated scatter factors were within 1.0% of measured, PDDs were within 0.5% past dmax, and diagonal profiles were within 0.5% for clinically relevant off‐axis distances (<10 cm). MBMS produced plans with ICIs < 1.5 and GIs < 5.0 for targets > 10 mm. Average point doses of the MBMS plans, measured by microDiamond, were within 0.31% of calculated (max 2.84%). Average per‐field planar pass rates were 98.0% (95.5% minimum) using a 2%/1 mm/10% threshold relative gamma analysis. E2E point dose measurements were within 1.5% of calculated and Gafchromic film pass rates were 99.6% using a 5%/1 mm/10% threshold gamma analysis.

Conclusion

The experience presented can be used to aid the commissioning of the Versa HD in the Brainlab MBMS treatment planning system, to produce safe and accurate SIMT cranial SRS treatments.
Interfacial Curvature in Confined Coculture Directs Stromal Cell Activity with Spatial Corralling of Pancreatic Cancer Cells
Authors: Nemec Stephanie , Lam Joey , Zhong Jingxiao , Heu Celine , Timpson Paul , Li Qing , Youkhana Janet , Sharbeen George , Phillips Phoebe A. , Kilian Kristopher A.
Published: March 2021

Interfacial cues in the tumor microenvironment direct the activity and assembly of multiple cell types. Pancreatic cancer, along with breast and prostate cancers, is enriched with cancer‐associated fibroblasts (CAFs) that activate to coordinate the deposition of the extracellular matrix, which can comprise over 90% of the tumor mass. While it is clear that matrix underlies the severity of the disease, the relationship between stromal‐tumor cell assembly and cell‐matrix dynamics remains elusive. Micropatterned hydrogels deconstruct the interplay between matrix stiffness and geometric confinement, guiding heterotypic cell populations and matrix assembly in pancreatic cancer. Interfacial cues at the perimeter of microislands guide CAF migration and direct cancer cell assembly. Computational modeling shows curvature‐stress dependent cellular localization for cancer and CAFs in coculture. Regions of convex curvature enhance edge stress that activates a myofibroblast phenotype in the CAFs with migration and increased collagen I deposition, ultimately leading to a central “corralling” of cancer cells. Inhibiting mechanotransduction pathways decreases CAF activation and the associated corralling phenotype. Together, this work reveals how interfacial biophysical cues underpin aspects of stromal desmoplasia, a hallmark of disease severity and chemoresistance in the pancreatic, breast, and prostate cancers, thereby providing a tool to expand stroma‐targeting therapeutic strategies.
Tunable White Light Emission in a Zero‐Dimensional Organic–Inorganic Metal Halide Hybrid with Ultra‐High Color Rendering Index
Authors: Song Gaomin , Li Zhongyuan , Gong Pifu , Xie Rong‐Jun , Lin Zheshuai
Published: March 2021

Organic–inorganic metal halide hybrids (OIMHs) with broadband white light (WL) emission are considered as a new type of rare‐earth‐free phosphors. Herein, eco‐friendly and stable Sn(IV) is selected as the B‐site inorganic cation to synthesize a 0D lead‐free OIMH (C5N2H14)SnCl6, in which the isolated [SnCl6]2− octahedra are separated by large organic [C5N2H14]2+ cations. Under different excitations, this compound exhibits warm white emission with a tunable color rendering index (CRI) from 80 to 97, the highest value among all known OIMHs, owing to the synergistic effect of [C5N2H14]2+ and [SnCl6]2− octahedra. This work presents a new strategy toward the WL materials with ultra‐high CRI by co‐regulating organic cations and inorganic polyhedra.
Perovskite Solar Cells: Current Trends in Graphene‐Based Materials for Transparent Conductive Electrodes, Active Layers, Charge Transport Layers, and Encapsulation Layers
Authors: Muchuweni Edigar , Martincigh Bice S. , Nyamori Vincent O.
Published: March 2021

The low fabrication cost, solution processability, and easy scalability of perovskite solar cells (PSCs), coupled with the rapid increase in their power conversion efficiency (PCE) from an initial value of 3.8% to a recently certified value of ≈25.5%, have enabled PSCs to compete with silicon‐based solar cells that currently exhibit PCEs of above 26.0%. However, unlike silicon‐based devices that are commercialized, the commercialization of PSCs is being hindered by factors, such as their poor long‐term operational stability, the high toxicity of lead (Pb), and the use of expensive materials, e.g., gold (Au) or silver (Ag). Hence, to address the aforementioned issues, significant research effort is exerted on novel graphene‐based materials, with their merits, which include low cost, excellent stability, nontoxicity, and remarkable optoelectronic properties. Nevertheless, graphene‐based PSCs are relatively less studied and are still in their infancy. This study presents recent developments in applying graphene‐based materials in electrodes, perovskite active layers, charge transport layers, and encapsulation layers of PSCs, focusing particularly on breakthroughs achieved over the last three years (2018–2020). The merits, shortcomings, and outlook of this field are discussed to propose future research directions for the low‐cost fabrication and commercialization of highly efficient and sustainable PSCs.
A murine model of tuberculosis/type 2 diabetes comorbidity for investigating the microbiome, metabolome and associated immune parameters
Authors: Sathkumara Harindra D. , Eaton Janet L. , Field Matt A. , Govan Brenda L. , Ketheesan Natkunam , Kupz Andreas
Published: March 2021

Tuberculosis (TB) is one of the deadliest infectious diseases in the world. The metabolic disease type 2 diabetes (T2D) significantly increases the risk of developing active TB. Effective new TB vaccine candidates and novel therapeutic interventions are required to meet the challenges of global TB eradication. Recent evidence suggests that the microbiota plays a significant role in how the host responds to infection, injury and neoplastic changes. Animal models that closely reflect human physiology are crucial in assessing new treatments and to decipher the underlying immunological defects responsible for increased TB susceptibility in comorbid patients. In this study, using a diet‐induced murine T2D model that reflects the etiopathogenesis of clinical T2D and increased TB susceptibility, we investigated how the intestinal microbiota may impact the development of T2D, and how the gut microbial composition changes following a very low‐dose aerosol infection with Mycobacterium tuberculosis (Mtb). Our data revealed a substantial intestinal microbiota dysbiosis in T2D mice compared to non‐diabetic animals. The observed differences were comparable to previous clinical reports in TB patients, in which it was shown that Mtb infection causes rapid loss of microbial diversity. Furthermore, diversity index and principle component analyses demonstrated distinct clustering of Mtb‐infected non‐diabetic mice vs. Mtb‐infected T2D mice. Our findings support a broad applicability of T2D mice as a tractable small animal model for studying distinct immune parameters, microbiota and the immune‐metabolome of TB/T2D comorbidity. This model may also enable answers to be found to critical outstanding questions about targeted interventions of the gut microbiota and the gut‐lung axis.
High‐Performance Porous Ionic Liquids for Low‐Pressure CO2 Capture**
Authors: Avila Jocasta , Lepre L. Fernando , Santini Catherine C. , Tiano Martin , Denis‐Quanquin Sandrine , Chung Szeto Kai , Padua Agilio A. H. , Costa Gomes Margarida
Published: March 2021

Porous ionic liquids are non‐volatile, versatile materials that associate porosity and fluidity. New porous ionic liquids, based on the ZIF‐8 metal–organic framework and on phosphonium acetate or levulinate salts, were prepared and show an increased capacity to absorb carbon dioxide at low pressures. Porous suspensions based on phosphonium levulinate ionic liquid absorb reversibly 103 % more carbon dioxide per mass than pure ZIF‐8 at 1 bar and 303 K. We show how the rational combination of MOFs with ionic liquids can greatly enhance low pressure CO2 absorption, paving the way towards a new generation of high‐performance, readily available liquid materials for effective low pressure carbon capture.
A Covalent Organic Framework Film for Three‐State Near‐Infrared Electrochromism and a Molecular Logic Gate
Authors: Hao Qing , Li Zhi‐Juan , Bai Bin , Zhang Xing , Zhong Yu‐Wu , Wan Li‐Jun , Wang Dong
Published: March 2021

A Kagome structure covalent organic framework (COF) film with three‐state NIR electrochromic properties was designed and synthesized. The COFTPDA‐PDA film is composed of hexagonal nanosheets with high crystallinity and has three reversible color states at different applied potentials. It has high absorption spectra changes in the NIR region, ascribed to the strong intervalence charge transfer (IVCT) interaction of the Class III mixed‐valence systems of the conjugated triphenylamine species. The film showed sub‐second response time (1.3 s for coloring and 0.7 s for bleaching at 1050 nm) and long retention time in the NIR region. COFTPDA‐PDA film shows superior NIR electrochromic properties in term of response time and stability, attributed to the highly ordered porous structure and the π–π stacking structure of the COFTPDA‐PDA architecture. The COFTPDA‐PDA film was applied in mimicking a flip‐flop logic gate with optical memory function.
Interfering with Metabolic Profile of Triple‐Negative Breast Cancers Using Rationally Designed Metformin Prodrugs
Authors: Babak Maria V. , Chong Kai Ren , Rapta Peter , Zannikou Markella , Tang Hui Min , Reichert Lisa , Chang Meng Rui , Kushnarev Vladimir , Heffeter Petra , Meier‐Menches Samuel M. , Lim Zhi Chiaw , Yap Jian Yu , Casini Angela , Balyasnikova Irina V. , Ang Wee Han
Published: March 2021

Triple‐negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, characterized by an aberrant metabolic phenotype with high metastatic capacity, resulting in poor patient prognoses and low survival rates. We designed a series of novel AuIIIcyclometalated prodrugs of energy‐disrupting Type II antidiabetic drugs namely, metformin and phenformin. Prodrug activation and release of the metformin ligand was achieved by tuning the cyclometalated AuIIIfragment. The lead complex3metwas 6000‐fold more cytotoxic compared to uncoordinated metformin and significantly reduced tumor burden in mice with aggressive breast cancers with lymphocytic infiltration into tumor tissues. These effects was ascribed to3metinterfering with energy production in TNBCs and inhibiting associated pro‐survival responses to induce deadly metabolic catastrophe.
Assembly of a Metal–Organic Framework (MOF) Membrane on a Solid Electrocatalyst: Introducing Molecular‐Level Control Over Heterogeneous CO2 Reduction
Authors: Mukhopadhyay Subhabrata , Shimoni Ran , Liberman Itamar , Ifraemov Raya , Rozenberg Illya , Hod Idan
Published: March 2021

Electrochemically active Metal‐Organic Frameworks (MOFs) have been progressively recognized for their use in solar fuel production schemes. Typically, they are utilized as platforms for heterogeneous tethering of exceptionally large concentration of molecular electrocatalysts onto electrodes. Yet so far, the potential influence of their extraordinary chemical modularity on electrocatalysis has been overlooked. Herein, we demonstrate that, when assembled on a solid Ag CO2 reduction electrocatalyst, a non‐catalytic UiO‐66 MOF acts as a porous membrane that systematically tunes the active site's immediate chemical environment, leading to a drastic enhancement of electrocatalytic activity and selectivity. Electrochemical analysis shows that the MOF membrane improves catalytic performance through physical and electrostatic regulation of reactants delivery towards the catalytic sites. The MOF also stabilizes catalytic intermediates via modulation of active site's secondary coordination sphere. This concept can be expanded to a wide range of proton‐coupled electrochemical reactions, providing new means for precise, molecular‐level manipulation of heterogeneous solar fuels systems.
Chemical Strategies for Making Strong Graphene Materials
Authors: Zhou Tianzhu , Cheng Qunfeng
Published: March 2021

Graphene materials have been widely applied in various fields because of their remarkable mechanical and electrical properties. However, two obstacles arise during the assembly of graphene platelets into macroscale graphene materials and composites that impair the performance of the resultant graphene materials: 1) the voids between the graphene platelets, and 2) the wrinkling of the graphene platelets. In the past decade, several strategies have been developed to eliminate these obstacles. These strategies result in strong macroscale graphene materials, such as graphene fibers with tensile strengths of over 3.4 GPa and sheets with tensile strengths of over 1.5 GPa, which have many practical applications. This Minireview summarizes the effective strategies for assembling graphene materials and compares their advantages and drawbacks. The preparation processes as well as the resulting fundamental mechanical properties and wide spectrum of electrical and magnetic properties are also discussed. Finally, our outlook for the future of this field is presented.
Maternal ethnicity and the prevalence of British pregnancies affected by neural tube defects
Authors: Peake Jordana N. , Knowles Rachel L. , Shawe Jill , Rankin Judith , Copp Andrew J.
Published: March 2021

Background

Few data are available on the prevalence of neural tube defects (NTDs) within different ethnic communities of the United Kingdom. This study aimed to calculate prevalence estimates for NTD‐affected pregnancies, classified by maternal ethnicity, and to explore why variations in prevalence might exist.

Methods

A cross‐sectional study was performed with data from regional congenital anomaly registers in England and Wales, for NTD‐affected pregnancies between 2006 and 2011. Using binomial regression models, we examined NTD‐affected pregnancy prevalence estimates and rate ratios (PRRs), by maternal ethnicity.

Results

The prevalence of NTDs was 12.14 per 10,000 births, with no differences between study years. Anencephaly, encephalocele and spina bifida occurred at 4.98, 1.37 and 5.80 per 10,000 births respectively. Mothers of Indian ethnicity were 1.84 times more likely (95% CI: 1.24, 2.73) and Bangladeshi mothers 2.86 times more likely (95% CI: 1.48, 5.53) than White mothers to have an NTD‐affected pregnancy, after adjusting for maternal deprivation and maternal age. The excess prevalence in Indian mothers was specifically for anencephaly (PRR 2.57; 95% CI: 1.52, 4.34), and in Bangladeshi mothers the trend was for increased spina bifida (PRR 3.86; 95% CI: 0.72, 8.69). Anencephaly in Indian mothers was especially associated with other congenital anomalies (non‐isolated NTDs).

Conclusions

Different British ethnic groups vary in NTD prevalence. The excess prevalence of anencephaly as a non‐isolated NTD in pregnancies of Indian mothers could indicate involvement of genetic or other unmeasured behavioral factors. Future work is needed to seek etiological explanations for the ethnicity differences and to develop improved methods for primary prevention.
When do threats mobilize managers for organizational change toward sustainability? An environmental belief model
Authors: Kump Barbara
Published: March 2021

In pursuit of counteracting today's environmental problems, corporate management will have to implement organizational changes factoring in sustainability, which is why it is important to understand exactly what leads managers to initiate these changes. It has been established that managers' personal values are critical for their behavior and that threats to these values can mobilize managers to change their actions. However, when confronted with environment‐related threats, managers may face value conflicts and various tensions between their aim to implement sustainable changes and their desire to fulfill business requirements of their job positions. Only recently have researchers begun to investigate the underlying beliefs that may lead managers to initiate organizational change toward sustainability. Borrowing theoretical assumptions from the domain of health psychology (from the well‐established health belief model), the present conceptual article develops an environmental belief model that specifies when exactly threats lead managers to initiate organizational change. The environmental belief model proposes that environment‐related threats trigger change (i) when managers believe that their firms are susceptible to these threats, (ii) the threats are considered as serious for the company, (iii) the perceived benefits of the change outperform (iv) the perceived barriers, and when there is (v) an external cue (e.g., an information campaign). All these propositions are supported with empirical findings from business contexts. Besides theoretical advancement on the role of environmental threats as precipitators of organizational change, the model provides guidance on how to frame environment‐related threats that will mobilize managers for organizational change toward sustainability.
Evaluating palliative opportunities in pediatric patients with leukemia and lymphoma
Authors: Labudde Emily J. , DeGroote Nicholas P. , Smith Susie , Ebelhar Jonathan , Allen Kristen E. , Castellino Sharon M. , Wasilewski‐Masker Karen , Brock Katharine E.
Published: March 2021

Background

Despite favorable prognoses, pediatric patients with hematologic malignancies experience significant challenges that may lead to diminished quality of life or family stress. They are less likely to receive subspecialty palliative care (PC) consultation and often undergo intensive end‐of‐life (EOL) care. We examined “palliative opportunities,” or events when the integration of PC would have the greatest impact, present during a patient's hematologic malignancy course and relevant associations.

Methods

A single‐center retrospective review was conducted on patients aged 0–18 years with a hematologic malignancy who died between 1/1/12 and 11/30/17. Demographic, disease, and treatment data were collected. A priori, nine palliative opportunity categories were defined. Descriptive statistics were performed. Palliative opportunities were evaluated over temporal quartiles from diagnosis to death. Timing and rationale of pediatric PC consultation were evaluated.

Results

Patients (n = 92) had a median of 5.0 (interquartile range [IQR] 6.0) palliative opportunities, incurring 522 total opportunities, increasing toward the EOL. Number and type of opportunities did not differ by demographics. PC consultation was most common in patients with lymphoid leukemia (50.9%, 28/55) and myeloid leukemia (48.5%, 16/33) versus lymphoma (0%, 0/4, p = 0.14). Forty‐four of ninety‐two patients (47.8%) received PC consultation a median of 1.8 months (IQR 4.1) prior to death. Receipt of PC was associated with transplant status (p = 0.0018) and a higher number of prior palliative opportunities (p = 0.0005); 70.3% (367/522) of palliative opportunities occurred without PC.

Conclusion

Patients with hematologic malignancies experience many opportunities warranting PC support. Identifying opportunities for ideal timing of PC involvement may benefit patients with hematologic cancers and their caregivers.
Graphene‐based Materials for Fighting Coronavirus Disease 2019: Challenges and Opportunities
Authors: Maqbool Imran , Rehman Faisal , Soomro Faheeda , Bhatti Zubeda , Ali Umeed , Jatoi Ashique Hussain , Lal Bhajan , Iqbal Muzaffar , Phulpoto Shahnawaz , Ali Akbar , Thebo Khalid Hussain
Published: March 2021

The coronavirus disease 2019 (COVID‐19) caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is considered as serious global threat of this time and greatest challenge for recent days. Several approaches have been carried out in this direction to fight against COVID‐19. Among these, nanotechnology is one of the promising approach to face these challenges in the current situation. Recently, graphene‐based nanomaterials have been explored for COVID‐19 due to its unique physicochemical properties. This mini review provides a recent progress in graphene‐based nanomaterials and its applications for diagnosis, detection, decontamination, and protection against COVID‐19. Further, main challenges and perspective for fundamental design and development of technologies based on graphene‐based materials are discussed and suitable directions to improve these technologies are suggested. This article will provide timely knowledge and future direction about this wonder materials in various biological applications.
Design and Synthesis of Simplified Polyketide Analogs: New Modalities beyond the Rule of 5
Authors: Menche Dirk
Published: March 2021

Natural products provide important lead structures for development of pharmaceutical agents or present attractive tools for medicinal chemistry. However, structurally complex and thus less accessible metabolites defying conventional drug‐like properties, as expressed by Pfizer's rule of five, have received less attention as medicinal leads. Traditionally, research focus has been on realizing total syntheses rather than developing more readily available analogs to resolve the critical supply issue. However, very recent studies with complex myxobacterial polyketides have demonstrated that considerable structural simplification may be realized with retention of biological potencies. The context, underlying rationale and importance of tailored synthetic strategies of three such case studies are presented, which may inspire further related activities and may eventually help exploiting the largely untapped biological potential of complex metabolites in general.
Metal‐based Heterogeneous Electrocatalysts for Electrochemical Reduction of Carbon Dioxide to Methane: Progress and Challenges
Authors: Zheng Yiqun , Wang Yu , Yuan Yuliang , Huang Hongwen
Published: March 2021

Electrochemical reduction of carbon dioxide (CO2ER) has attracted enormous research interest owing to the feasibility to consume the excessive CO2 in atmosphere arising from overconsumption of fossil fuels and store the chemical energy in value‐added chemicals. The conversion of CO2 into methane (CH4) is of great importance, and recent advance has allowed the design and utilisation of effective electrocatalysts with improved electrocatalytic performance regarding product selectivity and Faradaic efficiency. In this mini‐review, we discuss the recent progress and challenges of metal‐based heterogeneous electrocatalyst for CO2ER into CH4 by starting with fundamental mechanisms and designing principles of effective electrocatalysts. In the following sections, we present several successful demonstrations and analyze the effect and contribution arising from their chemical composition, facet, size, and other characters. Some challenges and promising strategies are discussed finally.
Behavior‐partitioned diversity reveals differential habitat values of gardens to butterfly communities
Authors: Lo Fiona H. Y. , Tsang Toby P. N. , Bonebrake Timothy C.
Published: March 2021

Diversity metrics, essential for habitat evaluation in conservation, are often based on occurrences records with little consideration of behavioral ecology. As species use diverse habitats to perform different behaviors, reliance on occurrence records alone will fail to reveal environmental conditions shaping the behavioral importance of habitats with respect to resource exploitation. Here, we integrated occurrence and behavioral records to quantify diversity and assessed how environmental determinants shape the behavioral importance of gardens to butterflies across Hong Kong. We conducted standardized butterfly sampling and behavioral observation, and recorded environmental variables related to climate, habitat quality, and landscape connectivity. We found differential responses of diversity and behavioral diversity metrics to environmental variables. Connectivity increased taxonomic richness based on occurrence and flying across records, while temperature reduced richness based on occurrence, settling and interaction records. Floral abundance increased richness based on nectaring records only. No environmental variable promoted the average number of behavioral types observed in each taxon. Our results suggest that connectivity and temperature determine the richness of butterflies reaching gardens, while floral abundance determines whether butterflies use the sites as nectaring grounds via modifying species behaviors. Our study demonstrates the utility in integrating behavioral and diversity data to reveal how environmental conditions shape behavioral importance of habitats.