bluuebunny/crossref_metadata_2025 huggingface dataset:
Statistical Modeling of Rainfall Distribution in Jos, Plateau State, Nigeria
Authors: Nwaigwe Chrysogonus Chinagorom , Ogbonna Chukwudi Justin , Achem Ojochekpa
Published: April 2023

Rainfall is a form of precipitation that occurs when water vapor in the atmosphere condenses into droplets which can no longer be suspended in the air. Flood is as a result of rainfall overflowing onto land. Flood is associated with a lot of negative consequences on the activities of man and animals in general and even threatens their existences. In this study, rainfall data obtained on rainfall occurrence in Jos, Plateau State were described. Five theoretical distributions; Weibull, Log-normal, Gamma, Extreme value type 1 and Log-Pearson type III distributions were fitted to the data. Kolmogorov-Smirnov and Anderson-Darling tests of goodness of fit were used to identify the most appropriate distribution. The Maximum likelihood estimator, Bayesian estimator and Principle of maximum entropy were used to estimate the parameters of the identified distribution. Alkaike information criterion (AIC) was used to compare the estimates of the parameters from the different estimators. The probability of the returning periods and the future amount of rainfall were then predicted. The results obtained show that the distribution is skewed to the left, with median annual rainfall of 2383.5mm and inter-quartile range of 432.4mm.The results obtained also show that the Log-Pearson Type III distribution best fitted the rainfall data with the Bayesian method as the best estimator of the parameters of the distribution. Results on the probability of the returning period show that it decreases as the number of years increases while the amount of rainfall increases as the number of year’s increases.
On the use of ARIMA and GARCH in Modelling Nigeria’s Naira: Us Dollar Monthly Exchange Rates
Authors: Tanko Ahmad, Nafisatu , Musa G. K. , Auta Musa, Salisu , Haruna Muhammed
Published: April 2023

This paper aimed at modelling the volatility of monthly average official exchange rate (Naira/USD) using the Autoregressive Integrated Moving Average (ARIMA) and Generalized Autoregressive Conditional Heteroscedasticity (GARCH) for the period January, 1981 to December, 2021. The data for the study was obtained from Central Bank of Nigeria 2021 Statistical Bulletin. The time plot, Augmented Dickey Fuller (ADF) and Phillip’s Perron (PP) were used to check for the Stationarity of the Series. It was discovered that the series is not stationary, thus the need for differencing to make it stationary. Based on the findings of the study, it was concluded that the ARIMA (0, 2,2) and GARCH (1,1) with Student’s t-distribution are the optimal models for modeling monthly average official exchange rates return (Naira/USD) in Nigeria.
Leaf Epidermal Microscopy, Chemo-Microscopy and GC-MS Analyses of Three Ocimum Species from Nigeria
Authors: Ugbabe G. E. , Owen-Obaseki E. , Abdulahi S. O. , Chinonyerem S. R. , Okhale S. E. , Ibrahim J. A.
Published: April 2023

Comparative analyses of the leaf epidermal microscopy, chemo-microscopy and GCMS analysis of essential oils from three Ocimum species were analyzed. Ocimum belong to the family Lamiaceae. Leaf epidermal microscopy revealed anomocytic stomata in the species studied. Ocimum basilicum has anomocytic stomata on both surfaces but were more abundant on the lower surface; cell walls were wavy on the upper surface and had glandular trichomes on both surfaces. Ocimum canum had anomocytic stomata on both surfaces; cell walls were wavy and trichomes were glandular and non-glandular occurring on both surfaces but occurring more on the upper surface. The non-glandular trichomes are cone-shaped with pointed tip. Ocimum gratissimum has anomacytic stomata on both surfaces occurring more on the lower surface; the cell walls are curved on both surfaces and glandular trichomes occur on both surfaces which are more abundant on the lower surface. The glandular trichomes are radially flagellated in all the species studied. Lignin, tannins, cellulose, mucilage, starch, calcium oxalate, oils and proteins were observed in all species studied. The GC-MS analyses of the leaf essential oils revealed 35 compounds for O. basilicum, 49 compounds for O. canum and 34 compounds for O. gratissimum with 3-allyl-6-methoxyphenol being the most abundant in O. basilicum (34.42%); 1-Cyclopentene-1-methanol,2-methyl-5-1-methyl, the most abundant in O. canum (29.56%) and thymol being the most abundant in O. gratissimum (48.04%). The leaf epidermal microscopy and the chemo-microscopy can be used for the standardization of the plant. Chemical composition of the three Ocimum species can be used for the treatment of several diseases.
Influence of Individualism on Entrepreneurial Opportunity Exploitation among Small and Medium Enterprises Owners in Tanzania
Authors: Kamwela Baraka Hebron , Jaensson Jan-Erik , Tonya Emmanuel
Published: April 2023

Aims: The main objective of this study was to examine the influence of individualism on entrepreneurial opportunity exploitation among small and medium enterprise owners in Tanzania through the mediation effect of innovativeness. Specific objectives were to examine the influence of individualism on entrepreneurial opportunity exploitation and to examine the mediating effect of innovativeness on the influence of individualism on entrepreneurial opportunity exploitation.

Methodology: The study employed an explanatory research design. 370 small and medium enterprise owners were studied using a cross-section survey questionnaire. Partial least square structural equation modelling was used to test the instruments’ validity and reliability and testing the direct and indirect hypotheses on the effects of individualism on entrepreneurial opportunity exploitation.

Results: After testing the hypotheses, the direct effects showed that individualism positively and significantly influences entrepreneurial opportunity exploitation among small and medium enterprise owners. Testing mediation effects, it was found that innovativeness partially mediates the relationship between individualism and entrepreneurial opportunity. Therefore, innovativeness has positive significant indirect effects on the relationship between individualism and entrepreneurial opportunity exploitation. 

Conclusion: Individualism directly and indirectly influences small and medium enterprise owners to exploit entrepreneurial opportunities. The study helps policymakers to understand that individualistic values, if well addressed in entrepreneurship policy, can help to promote innovativeness and entrepreneurial opportunity exploitation. Practically, the study implies that well-structured culture influences small and medium enterprises owners’ behavior to exploit opportunities.
Trisomy 5: A Rare Isolated Finding in Pediatric B-lymphoblastic Leukemia
Authors: Sachwani Kiran , Mansoor Neelum
Published: April 2023

Background and Objectives: In acute leukemia, all diagnostic criteria and treatment protocols are based on cytogenetic and molecular genetic findings. Despite recent advances in molecular biology, cytogenetic studies still play a pivotal role in the sub-classification of B-lymphoblastic leukemia (B-ALL). B-ALL is characterized by clonal cytogenetic abnormalities with numerical chromosomal aberrations being more common. An extra copy of chromosome 5 is common to see in cases with hyper diploidy. However, a gain of chromosome 5 as a sole anomaly is exceptionally rare in B-ALL. To date, trisomy 5 as a sole abnormality is reported in few cases only. We aimed to report the clinicopathologic profile of this rare finding to increase knowledge and highlight the disease course of these patients.

Methods: We report a case of a 14-year boy presented with fever, lethargy and episodes of nasal bleeding for two weeks. He was admitted to the pediatric oncology unit at Indus hospital and health network, Karachi. Flowcytometry performed on peripheral blood using 8-color flowcytometry. Conventional karyotyping was performed by GTG banding. FISH panel was comprised of dual color dual fusion probes for BCR::ABL1 and ETV6::RUNX1 whereas break apart probe for KMT2A (Metasystem, Germany). Digital image analysis for karyotyping and FISH was done on Leica Biosystems, Cytovision MB8.

Results: Flowcytometry results were consistent with B-ALL. Cytogenetic analysis on his bone marrow aspirate revealed trisomy 5 as a sole abnormality with no evidence of any other clonal cytogenetic abnormality. FISH studies for BCR::ABL1, ETV6::RUNX1 and KMT2A showed no evidence of gene rearrangements.

Conclusion: Trisomy 5 is a very rare cytogenetic aberration. Only few cases reported in children. Inferior outcome is reported in both children and adults. The increasing number of reported cases raises the possibility of a distinct cytogenetic entity. Its prognostic and therapeutic implications are yet to be explored.
Agroclimatic Risks and Endogenous Knowledge of Farmers in the Guidimouni Basin (South-Central Zinder, Niger)
Authors: Bagna Amadou Abdou
Published: April 2023

Agriculture is one of the most vulnerable sectors to the effects of climate change. The objective of this study is to analyze the impacts of rainfall variability on agricultural activities in the Guidimouni basin. The methodology used is based on the processing and analysis of daily rainfall data (Mirriah and Gouré stations from 1961 to 2019). It is complemented by a survey on perceptions of agroclimatic risks, impacts and strategies among a sample of 150 farmers in four villages. The results show that farmers have a good understanding of climate risks (80%) and are developing resilience strategies. These range from the intensification of irrigated crops (40%) to the use of natron (58%). In addition to these responses, the processing of products, particularly cassava (86%), and seasonal migration to Nigeria (28%) were also considered.
Analyzing the Spatio-temporal Changes in the Hasdeo Subbasin in Chhattisgarh Using Sentinel-2 Imagery
Authors: Yadav Usha , Tripathi M. P.
Published: April 2023

Understanding the dynamics of the world's landscapes is made possible by the multi-temporal change detection analysis made possible by Remote Sensing (RS) and GIS technologies. The current study provides an illustration of the spatiotemporal changes in land use land cover (LULC) of the Hasdeo subwatershed, Chhattisgarh, India, between 2016 and 2019 using Sentinel-2 imagery. To quantify the changes in the LULC area from 2016 to 2019, Sentinel-2 images from 2016 and 2019 were obtained. With the ERDAS Imagine software, the supervised classification method has been used. Eight different LULC classes, including forest, cultivated land, fallow land, water body, barren land, built-up land, mining and sand, were created using the image data of the research area. The outcome shows that between 2016 and 2019, there was an increase in built-up area and water body, while there was a decline in cultivated land, forest, and barren land. Kappa Coefficient accuracy is 88.00% and overall accuracy is 92.1% according to the LULC accuracy assessment for the data analysis. The paper's data base emphasises the significance of change detection approaches for spotting significant changes in land cover and for tracking the effects of human-induced change on the hydrological environment, behaviour, and setting of the Hasdeo sub watershed.
Federalism and Inter-Ethnic Relations: Identity, Socio-Economic Affairs and their Dynamics in Western Ethiopia
Authors: Jibat Keneni , Berisso Taddes , Adeto Yonas Adaye
Published: April 2023

This study aims to examine the relationship between Gumuz and Oromo along the border administrative area. The study employed qualitative descriptive research to meet the stated objective of the study. Purposive sampling techniques were used to gather information. To attain the study objective, interviews, observation, and focus group discussions were used as primary data. Primary data were gathered from different informants in both the Oromo and Gumuz communities. A total number of 48 informants participated in the study.  The study showed that pre-1991 and post-1991, the relations between the Gumuz and Oromo communities in the study area have been shaped by the intertwined political and economic contexts. The political context implies how federalism was perceived and implemented and the role of the central government. Following the reorganization of territories during the adoption of Federalism in 1991. The study's findings revealed that the federalism way of conflict resolution mechanism is still used as a major way of resolving conflict in the study area.
The Role of Institutions in Land Administration and Its Implications for Local Development: Case Study in the Nkambe Plateau, Northwest Cameroon
Authors: Nformi Roland , Godlove Funwi , Randy Yinkfu , Awudu Ngwani
Published: April 2023

With the growing diversification in land uses, land administration faces numerous challenges in the Nkambe Plateau. Moreover, as a result of population growth, land scarcity, land cover change and competition between farmers for suitable arable farmland and grazing land, the ineffective implementation of land statutes impedes local development in the Nkambe Plateau. The early migratory movement and resettlement of communities in the Nkambe Plateau, globalization, liberalization and climate change are the key factors that drive ineffective implementation of land statutes. The main aim of this study is to investigate challenges faced by institutions in land administration and implications on local development in the Nkambe Plateau, Northwest Cameroon. The study was based on a survey conducted among 200 participants using stratified random sampling technique. Data is analysed qualitatively and the findings suggest that proper land administration and development in Nkambe Plateau cannot be separated. Furthermore, the study holds that, the way forward in proper land administration is for the Government and its development partners to seek means by which the relevant aspects of land administration of the indigenous traditional institutions can be synthesised with those of the administrative institutions in order to harness their potentials. This is because any state intervention in proper land administration which is not firmly rooted in the people’s culture will not be sustainable. Thus, involving indigenous traditional institutions in the process of land administration offer greater prospects for social cohesion and sustainable development.
PENGARUH PARAMETER BANGUNAN HIJAU GBCI TERHADAP FASE PROYEK
Authors: Wiyono Edwin S. , Dusia Enry L. , Alifen Ratna S. , Rahardjo Jani
Published: April 2023

Green building concept has been widely developed globally as well as in Indonesia. Green Building Council Indonesia (GBCI) is the institution that organizes the green building certification in Indonesia. The view from construction parties is needed to understand the level of interest and level of implementation of green building parameters and the impact of green building parameters on project life cycle time. This research carried out by distributing questionnaires to construction parties in Jakarta and Surabaya. Descriptive analysis and Structural Equation Modelling is used to understand the respondent views of the green building parameters and the impact of green building parameters on project life cycle time.The results showed that the level of interest of green building parameters is high. The comparison between level of importance and level of implementation shows that the implementation rate is lower than the importance rate. Water conservation is a significant aspect affecting the project life cycle time specifically the design stage, while the other aspects haven’t been significantly affecting project life cycle time.
Reimagining Institutionalization and a Continuum of Care for People Experiencing Homelessness and Mental Illness
Authors: Koh Katherine A. , Gorman Benjamin Land
Published: April 2023

This Viewpoint discusses the continuum of preventive, community, and institutional services necessary for improving care for people with mental illness experiencing homelessness.
Cost-Free Preventive Care Under the ACA Faces Legal Challenge
Authors: Gluck Abbe R. , Gostin Lawrence O.
Published: April 2023

This Viewpoint examines the recent decision by a federal district court that undercuts the Affordable Care Act’s mandate for cost-free coverage of preventive services, including contraception, some vaccinations, many screenings, and preexposure prophylaxis for HIV, among others.
Health Care Access and Affordability Among US Adults Aged 18 to 64 Years With Self-reported Post–COVID-19 Condition
Authors: Karpman Michael , Zuckerman Stephen , Morriss Sarah
Published: April 2023

Importance

Many US adults report having post–COVID-19 condition (PCC), but little is known about their access to health care.

Objective

To estimate the association of PCC with access and affordability challenges among US adults aged 18 to 64 years.

Design, Setting, and Participants

This survey study used data from the Health Reform Monitoring Survey, a probability-based internet survey conducted June 17 to July 5, 2022. Participants included a nationally representative sample of 9484 US adults ages 18 to 64 years drawn from the Ipsos KnowledgePanel.

Main Outcomes and Measures

Self-reported PCC was defined as experiencing symptoms more than 4 weeks after first having COVID-19 that were not explained by another condition or factor. Access and affordability outcomes included having a usual place of care; forgoing care in the past 12 months because of costs, difficulty finding clinicians, or difficulty using health insurance; having problems paying family medical bills in the past 12 months; and having past-due medical debt.

Results

Of 19 162 panel members recruited for the survey, 9599 individuals completed the survey (completion rate, 50.1%) and 9484 respondents were included in the final analytic sample (4720 females [50.6%, weighted]; mean [SD] age, 41.0 [13.5] years). A total of 3382 respondents (36.4%; 95% CI, 34.7%-38.2%) reported ever being diagnosed with COVID-19, among whom, 833 respondents (22.5%; 95% CI, 20.9%-24.2%) reported currently having PCC. After adjustment for differences in demographic, health, and geographic characteristics, adults with PCC were more likely than 2549 adults with a COVID-19 diagnosis but no report of PCC and 6102 adults never diagnosed with COVID-19 to report unmet health care needs in the past 12 months because of the following challenges: costs (27.0%; 95% CI, 23.2%-30.7% vs 18.3%; 95% CI, 15.9%-20.7% and 17.5%; 95% CI, 15.4%-19.6%) and difficulties finding clinicians accepting new patients (16.4%; 95% CI, 14.3%-18.4% vs 10.1%; 95% CI, 8.8%-11.5% and 10.7%; 95% CI, 9.6%-11.8%), getting a timely appointment (22.0%; 95% CI, 19.3%-24.8% vs 14.4%; 95% CI, 13.2%-15.7% and 13.9%; 95% CI, 12.9%-14.8%), and getting health plan care authorization (16.6%; 95% CI, 14.6%-18.6% vs 10.8%; 95% CI, 9.6%-12.1% and 10.3%; 95% CI, 9.4%-11.2%) (P < .001 for all comparisons).

Conclusions and Relevance

This study found that adults aged 18 to 64 years with PCC were more likely than other adults to have difficulty getting and paying for health care. These findings suggest that policies aimed at improving access and affordability may focus on accelerating development of treatments and clinical guidelines, training clinicians, and addressing insurance-related administrative and cost barriers.
A Bio‐Inspired Temperature‐Arousing Battery with Giant Power for Fire Alarming
Authors: Li Xinlei , Lyu Shanzhi , Jia Jichen , Gao Naiwei , Wu Xun , Ma Yingchao , Wang Yapei
Published: April 2023

Forest fire has been becoming a conscious theme as it causes huge loss of life and ghastly impact on the ecological environment. Temperature sensor appropriate for large‐area distribution in forest is rising as a subject of considerable speculation to build a fire alarming network. This strategy needs power supplies that can support fire alarming sensors in long term. Herein, a concept of temperature‐arousing battery (TAB) is conceived that has no energy consumption at normal temperaturewhile becoming activated in fire scenario. The TAB is made of a thermoelectric (TE) generator deposited with exothermic and endothermic materials on its hot sink and cold sink, respectively. Learning from bombardier beetles, the exothermic reaction and endothermic reaction can only happen when the thermal‐responsive switches to isolate reactants are triggered in the event of fire occurrence. Even in an isothermal atmosphere, a remarkable temperature difference is formed between two sinks of TE generator, accordingly producing a thermoelectric voltage higher than 5.0 V and a giant power over 1.0 W, which are high enough to power a wireless signal transmitter. In the practical tests, the integrated self‐powered alarming system can transmit an electrical signal in 79 s when the TAB touches a forest fire.
Bioinspired Photonic Microchip with Molecularly Imprinted Polymer for Single Recognition of c‐Myc Protein in Predictive Medical Diagnostics
Authors: Xu Jun , Liu Xianghui , Sun Ya , Zhang Di , Zhou Han , Fan Tongxiang
Published: April 2023

Monitoring of trace c‐Myc protein as the biomarker of ubiquitous cancers is critical in achieving predictive medical diagnostics. However, qualitative and quantitative detection of c‐Myc protein with superior single selectivity and sensitivity is still challenging. Herein, a bioinspired photonic sensing microchip for single recognition of c‐Myc protein is outlined with two synergistic aspects involving chemical and physical design criteria. Chemical design uses specific molecularly imprinted polymer (MIP) with exquisite complementarity in its chemical functions and spatial geometries to targeted c‐Myc protein, leading to excellent sensitivity and selectivity for single identification. Physical design involves optical geometrical double‐reflection polarization rotation and multilayer interference of the fabricated periodic photonic architecture inspired by Papilio palinurus butterfly wings to enhance the spectral diversity of reflectance. Therefore, a one‐of‐a‐kind sensing platform integrates the advantages of MIP and bioinspired photonic structure is demonstrated to actualize distinctive signal conversion and amplification for qualitative and quantitative detection of trace c‐Myc protein, accompanied with superior sensitivity (detection limit is 0.014 µg mL−1), selectivity, stability, anti‐interference ability as well as rapid response/recovery time. This sensor microchip uniquely ventures into the territory of functionally combining bioinspired photonic structure with MIP absorbers, proven promising for prevention or diagnosis of cancers in medical field.
Collagen‐Based Dissolving Microneedles with Flexible Pedestals: A Transdermal Delivery System for Both Anti‐Aging and Skin Diseases
Authors: Lv Hongqian , Gao Nan , Zhou Qixin , Wang Yan , Ling Guixia , Zhang Peng
Published: April 2023

Biocompatible polymer microneedles (MNs) are emerging as a promising platform for transdermal drug delivery, especially for facial treatments. Therefore, an MN patch in this study uses hydrolyzed collagen (HC) contained in skin cells as the main raw material and adopts a two‐step cast method to develop a rapidly dissolving microneedle (DMN) to deliver collagen in a simple and minimally invasive way, allowing the release of the encapsulated drug in the skin. By optimizing the formulation and proportion of HC and auxiliary support materials, the mechanical strength required to pierce the skin is obtained, while the soft pedestal allows for flexibility in application. The DMNs can dissolve completely in the skin within 15 min and release within ≈ 8 h, and do not cause toxicity or irritation when being applied. In contrast to the ineffectiveness of oral and external application, and the high risk of dermal injection, drug‐loaded DMNs overcome the drawbacks of traditional methods with direct penetration and minimally invasive manner, enabling efficient and safe treatment. The successful preparation and research of HC DMNs have innovative and practical significance in this field, and it is expected to become a simple, effective, and popular transdermal drug delivery platform for cosmetics.
Hemoadhican, a Tissue Adhesion Hemostatic Material Independent of Blood Coagulation
Authors: Kong Changchang , Chen Shijunyin , Wang Xianjin , Hu Chengtao , Li Bing , Fu Renjie , Zhang Jianfa
Published: April 2023

Uncontrolled hemorrhage is a leading cause of death, emphasizing the need for novel hemostatic agents. Here, a novel hemostatic polysaccharide hemoadhican (HD) is screened out by analyzing the rheological properties of screened material mixed blood sludges, which is prepared by mixing polysaccharide granules and whole blood to mimic the coagulation in vitro. HD is produced by a bacterial isolate Paenibacillus sp.1229, and the repeating units of HD are →)‐α‐L‐Rhap‐(1→3)‐β‐D‐Glcp‐(1→4)[4,6‐ethylidene‐α‐D‐Galp‐(1→4)‐α‐D‐Glcp‐(1→3)]‐α‐D‐Manp‐(1→. Compared to chitosan and celox, HD achieves more effective hemostasis in animal models with mouse and rat femoral arteries, rat carotid arteries, and rabbit femoral arteries. Especially, HD maintains an excellent hemostatic capability in animals with heparin‐induced hemorrhage diathesis. In vitro experiments show HD granules can quickly absorb a small amount of blood component to create a hemophobic blood sludge resistant to high pressure. The blood sludge firmly adheres to damaged tissue and efficiently repels blood. In vitro experiments show that HD does not actively trigger blood coagulation cascade and is independent of blood conditions including heparin treatment. In addition, HD moisturizes wounds and accelerates wound healing, exhibiting excellent biodegradability, and hemocompatibility. The results indicate that HD is a promising hemostatic material for treating traumatic hemorrhages and uncontrollable surgical bleeding.
Physicochemical Dual Cross‐Linking Conductive Polymeric Networks Combining High Strength and High Toughness Enable Stable Operation of Silicon Microparticle Anodes
Authors: Zhang Biao , Dong Yanling , Han Jingrui , Zhen Yunjing , Hu Chuangang , Liu Dong
Published: April 2023

The poor interfacial stability and insufficient cycling performance caused by undesirable stress hinder the commercial application of silicon microparticles (µSi) as next‐generation anode materials for high‐energy‐density lithium‐ion batteries. Herein, a conceptionally novel physicochemical dual cross‐linking conductive polymeric network is designed combining high strength and high toughness by coupling the stiffness of poly(acrylic acid) and the softness of carboxyl nitrile rubber, which includes multiple H‐bonds, by introducing highly branched tannic acid as a physical cross‐linker. Such a design enables effective stress dissipation by folded molecular chains slipping and sequential cleavage of H‐bonds, thus stabilizing the electrode interface and enhancing cycle stability. As expected, the resultant electrode (µSi/PTBR) delivers an unprecedented high capacity retention of ≈97% from 2027.9 mAh g−1 at the 19th to 1968.0 mAh g−1 at the 200th cycle at 2 A g−1. Meanwhile, this unique stress dissipation strategy is also suitable for stabilizing SiOx anodes with a much lower capacity loss of ≈0.012% per cycle over 1000 cycles at 1.5 A g−1. Atomic force microscopy analysis and finite element simulations reveal the excellent stress‐distribution ability of the physicochemical dual cross‐linking conductive polymeric network. This work provides an efficient energy‐dissipation strategy toward practical high‐capacity anodes for energy‐dense batteries.
Inducing Single Spin‐Polarized Flat Bands in Monolayer Graphene
Authors: Jugovac Matteo , Cojocariu Iulia , Sánchez‐Barriga Jaime , Gargiani Pierluigi , Valvidares Manuel , Feyer Vitaliy , Blügel Stefan , Bihlmayer Gustav , Perna Paolo
Published: April 2023

Due to the fundamental and technological implications in driving the appearance of non‐trivial, exotic topological spin textures and emerging symmetry‐broken phases, flat electronic bands in 2D materials, including graphene, are nowadays a relevant topic in the field of spintronics. Here, via europium doping, single spin‐polarized bands are generated in monolayer graphene supported by the Co(0001) surface. The doping is controlled by Eu positioning, allowing for the formation of a ‐valley localized single spin‐polarized low‐dispersive parabolic band close to the Fermi energy when Eu is on top, and of a π* flat band with single spin character when Eu is intercalated underneath graphene. In the latter case, Eu also induces a bandgap opening at the Dirac point while the Eu 4f states act as a spin filter, splitting the π band into two spin‐polarized branches. The generation of flat bands with single spin character, as revealed by the spin‐ and angle‐resolved photoemission spectroscopy (ARPES) experiments, complemented by density functional theory (DFT) calculations, opens up new pathways toward the realization of spintronic devices exploiting such novel exotic electronic and magnetic states.
Fabrication of La‐Doped MoS2 Nanosheets with Tuned Bandgap for Dye Degradation and Antimicrobial Activities, Experimental and Computational Investigations
Authors: Ikram Muhammad , Ilyas Binas , Haider Ali , Haider Junaid , Ul‐Hamid Anwar , Shahzadi Anum , Goumri‐Said Souraya , Kanoun Mohammed Benali , Nabgan Walid , Mahmood Asif
Published: April 2023

The development of efficient catalysts with a large number of active sites, tunable bandgap, and large surface area has been very challenging. In addition, a significant bottleneck in the application of catalysts for water treatment is their dissolution under extreme conditions, such as highly acidic or highly alkaline conditions that lead to poor application of the reported materials in real‐world applications. In this study, the lanthanum (La)‐doped molybdenum disulfide (MoS2) nanosheets are reported for efficient breakdown of toxic pollutants from wastewater under a wide pH range from strongly alkaline to strongly acidic solutions. The La‐MoS2 nanosheets (NSs) are prepared by a facile hydrothermal approach using a two‐step methodology. A redshift is observed upon La doping, indicating that the bandgap is lowered after La doping in MoS2. The changes in bandgap and electronic structure are further investigated using the density functional theory (DFT), which reveal that doping of La introduces new states within the bandgap region, allowing for further induced energy transitions. The La‐MoS2, having a doping concentration of 2%, exhibits the highest catalytic activity against methylene blue (MB) in neutral, acidic, and alkaline solutions, as well as substantial inhibitory activity for bacterial strains such as Escherichia coli (E. coli). In summary, the modified catalyst provides a pathway to design highly efficient catalysts for all pH range water treatment as well as good activity against microbes.
Spatially Controlled Single Photon Emitters in hBN‐Capped WS2 Domes
Authors: Cianci Salvatore , Blundo Elena , Tuzi Federico , Pettinari Giorgio , Olkowska‐Pucko Katarzyna , Parmenopoulou Eirini , Peeters Djero B. L. , Miriametro Antonio , Taniguchi Takashi , Watanabe Kenji , Babinski Adam , Molas Maciej R. , Felici Marco , Polimeni Antonio
Published: April 2023

Monolayers (MLs) of transition‐metal dichalcogenides host efficient single‐photon emitters (SPEs) usually associated to the presence of nanoscale mechanical deformations or strain. Large‐scale spatial control of strain would enhance the scalability of such SPEs and allow for their incorporation into photonic structures. Here, the formation of regular arrays of strained hydrogen‐filled one‐layer‐thick micro‐domes obtained by H‐ion irradiation and lithography‐based approaches is reported. Typically, the H2 liquefaction for temperatures T<32 K causes the disappearance of the domes preventing their use as potential SPEs. Here, it is shown that the dome deflation can be overcome by hBN heterostructuring, that is by depositing thin hBN flakes on the domes. This leads to the preservation of the dome structure at all temperatures, as found by micro‐Raman and micro‐photoluminescence (µ‐PL) studies. Eventually, spatially controlled hBN‐capped WS2 domes show the appearance, at 5 K, of intense emission lines originating from localized excitons, which are shown to behave as quantum emitters here. The electronic properties of the emitters are addressed by time‐resolved µ‐PL yielding time decays of 1–10 ns, and by magneto‐µ‐PL measurements. The latter provide an exciton magnetic moment a factor of two larger than the value observed in planar strain‐free MLs.
Aggregation‐Dependent Thermally Activated Delayed Fluorescence Emitters: AIE or ACQ?
Authors: Wu Yaxun , Ni Fan , Chen Zhanxiang , Yang Wei , Xiang Yepeng , Gong Shaolong , Cao Xiaosong , Yang Chuluo
Published: April 2023

The understanding of the excited state dynamics of thermally activated delayed fluorescence (TADF) materials is crucial. In this study, two donor–acceptor‐type TADF emitters with highly twisted conformation are synthesized. The emitters with subtle chemical modification of donor unit exhibit opposite aggregation luminescent behaviors: aggregation‐induced emission (AIE) and aggregation‐caused quenching (ACQ). Through the photophysical properties study, crystallographic analysis, and theory simulations, it is discovered that X‐aggregation supports AIE behavior by restricting the intramolecular motions and preserving TADF emission via an efficient reverse intersystem crossing (RISC) process, but on the other hand, H‐aggregation leads to ACQ behavior due to inhibited RISC, disabled TADF channel, and weak phosphorescence from radiative low‐lying triplet state. The findings shed light on the excited‐state dynamic behaviors of TADF emitters, which are dependent on aggregation.
Mapping subsurface tile lines on a research farm using aerial photography, paper maps, and expert knowledge
Authors: Rahmani Shams R. , Schulze Darrell G.
Published: April 2023

Accurate maps of subsurface tile drainage lines are needed for agronomic and environmental research studies and the maintenance of current tile drainage systems. In this study, tile lines at the Purdue University Agronomy Center for Research and Education near West Lafayette, Indiana were located using a combination of visual aerial photo interpretation, expert knowledge, and paper construction drawings. The mapping accuracy was assessed at 27 locations where tile lines were located physically using a tile probe. Tile lines were correctly predicted 89% of the time with an average spatial accuracy of ±1.23 m of the true tile locations. This approach was better than a previous tile line location map prepared using an automated remote sensing method, which had an average spatial accuracy of ±2.12 m.
Role of market participation on smallholder vegetable farmers' wellbeing: Evidence from matching approach in Eastern India
Authors: Dey Shiladitya , Singh Piyush K.
Published: April 2023

The study identifies determinants of vegetable farmers' market participation and evaluates their impact on households' welfare. In this study, we collected 175 cross‐sectional household data and employed a probit regression model to identify the determinants of vegetable farmers' market participation. The study estimates the impact of market participation on households' income and per capita consumption using the propensity score matching approach (PSM). Subsequently, the study used the endogenous switch regression (ESR) model to control sample selection bias and unobserved heterogeneity. ESR also evaluates the robustness of PSM outcomes. Results from PSM and ESR approaches suggest that vegetable market participation positively and significantly impacts smallholders' income and consumption expenditure. The study rejects the null hypothesis that vegetable market participation does not significantly impact farmers' welfare. Results show that vegetable market participation increases the farmers' monthly income and annual per capita consumption expenditure on average by Indian rupee (INR) 8360 and INR 26,410, respectively. Findings also indicate that household size, distance to market, off‐farm income, access to training, price information, vehicle ownership, and storage systems are critical determinants of vegetable farmers' market participation. Identified determinants may support policymakers in designing suitable agricultural marketing policies to reduce market entry barriers and motivate farmers for market participation. [EconLit Citations: Q13, D60].
Intrinsic Decay Property of Ti/TiOx/Pt Memristor for Reinforcement Learning
Authors: Dai Yuehua , Guo Wenbin , Feng Zhe , Xu Zuyu , Zhu Yunlai , Yang Fei , Wu Zuheng
Published: April 2023

A memristor‐based reinforcement learning (RL) system has shown outstanding performance in achieving efficient autonomous decision‐making and edge computing. Sarsa (λ) is a classical multistep RL algorithm that records state with λ decay and guides policy updates, significantly improving the algorithm convergence speed. However, λ decay implementation of traditional computing hardware is confined by the extensive computation of power exponential decay. Herein, the value update equation for Sarsa (λ) is implemented by using the topological structure of the memristor array, without complex circuits. Where, most importantly, the critical λ decay function is realized by a TiOx‐based memristor with conductance decay property. The energy required for floating‐point operations can be significantly reduced while accelerating the convergence speed. Then, a path planning task is demonstrated based on intrinsic conductance decay property and shows outstanding performance. Finally, the information of rounds used for the task is obtained, which is based on the intrinsic decay property of the TiOx‐based memristor, maps into a 32 × 32 memristor array in parallel to calculate the value of each round. The results indicate that the experimental data have similar results to the simulations. Herein, thus, it provides a hardware‐enabled scheme for the memristor‐based RL algorithm implementation.
Extremely Large‐Stroke Hair Artificial Muscles with Fast Recovery Prepared by a Facile and Green Method
Authors: Xiao Qian-Ru , Xu Peng , Sun Si , Qiang Xiao-Li , Shi Xiao-Long
Published: April 2023

Twisted artificial muscles based on natural fibers are of special interest in diverse fields. However, current research is limited either by the material itself, or by the preparation methods requiring complex processing or specialized equipment. In this study, a facile and green method is introduced to prepare hair artificial muscles with extremely large tensile stroke and fast recovery. The maximum tensile stroke for the hair artificial muscles upon water actuation is as large as 10 000% and the large‐stroke muscles can recover fast in ethanol. In addition, these hair artificial muscles maintain their excellent performance after either 100 water–ethanol stimulation cycles or staying in open air for 5 months. Moreover, the hair artificial muscle is able to contract by 59% when lifting 10 times its own weight, pull a wheel model or climb a long distance under water, and work as a smart water‐sensitive switch. This work provides new insights into the development of simpler and more environmentally friendly methods for preparing advanced natural fiber‐based artificial muscles that have broad applications in soft robotics and biomedical engineering. An interactive preprint version of the article can be found here: https://doi.org/10.22541/au.167385630.01748766/v1.
Radical Cascade Cyclization of Alkene‐Tethered Compounds: Versatile Approach towards Ring‐Fused Polycyclic Structures
Authors: Liu Han , Wang Lei , Yu Jin‐Tao
Published: April 2023

Ring‐fused polycyclic structures widely exist in a myriad of natural products and pharmaceutical molecules. Consequently, the construction of such structures from readily available substrates becomes an important researching topic in organic synthesis. Triggered by the addition of radicals to the (activated or unactivated) double bonds in alkenes, the subsequent intramolecular addition/cyclization leads to polycyclic compounds. Following this procedure, a variety of functionalized ring‐fused structures were formed. Great achievements have been witnessed recently. Those works provided efficient, atom economy, and operational simple approaches toward versatile functionalized polycyclic structures from readily available alkene‐based substrates. Here, we summarized the recent achievements on the formation of ring‐fused polycyclic structures via the radical‐triggered cascade reactions of alkenes. Construction of polycyclic structures with no less than 3 fused rings developed during the last decade were included in this Review, corresponding mechanisms were also discussed.
Low glucose induced Alzheimer's disease‐like biochemical changes in human induced pluripotent stem cell‐derived neurons is due to dysregulated O‐GlcNAcylation
Authors: Huang Chia‐Wei , Rust Nicholas C. , Wu Hsueh‐Fu , Yin Amelia , Zeltner Nadja , Yin Hang , Hart Gerald W.
Published: April 2023

Introduction

Sporadic Alzheimer's disease (sAD) is the leading type of dementia. Brain glucose hypometabolism, along with decreased O‐GlcNAcylation levels, occurs before the onset of symptoms and correlates with pathogenesis. Heretofore, the mechanisms involved and the roles of O‐GlcNAcylation in sAD pathology largely remain unknown due to a lack of human models of sAD.

Methods

Human cortical neurons were generated from pluripotent stem cells (PSCs) and treated with glucose reduction media.

Results

We found a narrow window of glucose concentration that induces sAD‐like phenotypes in PSC‐derived neurons. With our model, we reveal that dysregulated O‐GlcNAc, in part through mitochondrial dysfunction, causes the onset of sAD‐like changes. We demonstrate the therapeutic potential of inhibiting O‐GlcNAcase in alleviating AD‐like biochemical changes.

Discussion

Our results suggest that dysregulated O‐GlcNAc might be a direct molecular link between hypometabolism and sAD‐like alternations. Moreover, this model can be exploited to explore molecular processes and for drug development.

HIGHLIGHTS

Lowering glucose to a critical level causes AD‐like changes in cortical neurons.

Defective neuronal structure and function were also recapitulated in current model.

Dysregulated O‐GlcNAcylation links impaired glucose metabolism to AD‐like changes.

Mitochondrial abnormalities correlate with O‐GlcNAcylation and precede AD‐like phenotype.

Our model provides a platform to study sAD as a metabolic disease in human neurons.
Divergent Total Syntheses of (+)‐Vulgarisins A–E
Authors: Xu Kaixiang , Mu Shan , Rao Huijuanzi , Hu Jialei , Ding Hanfeng
Published: April 2023

The asymmetric total syntheses of (+)‐vulgarisins A–E, which share a rare and highly oxygenated [5‐6‐4‐5] tetracyclic core structure that were isolated fromP. vulgarisLinn., have been described for the first time in a divergent manner. Key transformations include: 1) a catalytic asymmetric intramolecular cyclopropanation to forge the A ring bearing desired stereochemistry at C14; 2) a one‐pot borylation/conjugate addition process for creation of the C1−C11 bond; 3) a Wolff ring contraction to assemble the bicyclo[3.2.0]heptane subunit (CD rings); and 4) a stereocontrolled pinacol cyclization for construction of the central B ring of the natural products.
Suspension of a single sphere in a stirred tank with transitional flow
Authors: Wang Jianghao , Huang Fenglei , Zhang Kun , Wang Chao , Li Zhipeng , Gao Zhengming , Derksen Jos
Published: April 2023

The lift‐off characteristics of a single spherical particle in a stirred tank with transitional flow generated by a Rushton impeller have been explored in detail by using image capturing and processing techniques. We found three kinds of typical particle suspension motions, namely, the lightest PMMA particle first moves upward from the bottom center of the tank to a certain height and then spirals up to the impeller, the heavier POM particle rises to a certain height vertically and then it spirals down to the tank bottom, the still heavier PTFE and glass particles jump at random when they are rolling irregularly on the tank bottom. The single‐phase flow field of the stirred tank was measured by using 2D‐PIV technique to address the mechanism of the particle lift‐off. The random distribution of the regions with larger liquid velocity closely above the tank bottom might be the reason why the PTFE and glass particles were lifted off randomly. As for the PMMA and POM particles being lifted from the bottom center and then stagnating at a certain height, the bulk flow dominates the particle suspension.
Genetic variation and population structure of a widely distributed damselfly (Ischnura senegalensis)
Authors: Jiang Bin , Zhang Jiang , Bai Xinrui , Zhang Yongmei , Yao Yu , Li Jia , Yu Guozhi , He Shulin , Sun Yang , Mikolajewski Dirk J.
Published: April 2023

Ischnura senegalensis Rambur, 1842 is among the most widespread damselfly species in the world. Unlike dragonflies with strong migration abilities, I. senegalensis have limited dispersing abilities. Gene flow among I. senegalensis populations may be greatly influenced by anthropogenic disturbance, fragmented suitable habitats, sea straits, or even global warming. In this study, to investigate the genetic diversity of I. senegalensis populations, we sequenced and collected 498 cytochrome oxidase I sequences across the Old World. Haplotype network analysis showed 51 haplotypes and I. senegalensis could be grouped into four regions (Afrotropical region, Oriental region, main Islands of Japan, and the Ryukyu Islands), each of which contains different dominant haplotypes. Based on molecular variance analysis, we found that populations from the Afrotropical region have quite a low gene flow with the Asian populations (except Yemen). Furthermore, rice cultivation may aid the dispersion of I. senegalensis in the oriental region. Populations from the Ryukyu Islands show the highest genetic diversity, which may be due to the geological separation among islands. Our results prove that I. senegalensis has great genetic diversity among different populations across the world.
Attenuation of phenobarbital‐induced cytochrome P450 expression in carbon tetrachloride‐induced hepatitis in mice models
Authors: Fujino Chieri , Kuzu Taiki , Kubo Yukine , Hayashi Kurumi , Ueshima Satoshi , Katsura Toshiya
Published: April 2023

Certain pathological conditions, such as inflammation, are known to affect basal cytochrome P450 (CYP) expression by modulating transcriptional regulation, and the pharmacokinetics of drugs can vary among patients. However, changes in drug‐induced CYP expression under pathological conditions have not been elucidated in detail. Here, we investigated the effects of hepatic inflammation and injury on phenobarbital‐induced expression of CYP isoforms in mice. Phenobarbital was administered once as a CYP inducer in the carbon tetrachloride‐induced hepatitis model mice. The mRNA expression levels of Cyp3a11 and Cyp2b10 in the liver and small intestine were measured using reverse transcription polymerase chain reaction. The enzymatic activity of CYP3A in liver S9 was evaluated using midazolam as the substrate. Phenobarbital increased the mRNA expression of Cyp3a11 and Cyp2b10 in the liver of healthy mice, but not in the small intestine. Increased mRNA expression of hepatic Cyp3a11 and Cyp2b10 by phenobarbital was significantly suppressed in the hepatitis model mice. Hepatitis also suppressed the increased CYP3A enzymatic activity induced by phenobarbital in liver S9, consistent with the results of Cyp3a11 mRNA expression. These results suggest that the inducibility of CYP by phenobarbital may vary in patients with hepatitis, indicating that pharmacokinetic drug–drug interactions can be altered under certain pathological conditions.