bluuebunny/crossref_metadata_2025 huggingface dataset:
Phenotypic Detection of Extended-spectrum Beta-lactamase-Producing Escherichia coli and Klebsiella pneumoniae Isolated from Hospital and Environmental Sources in Enugu Metropolis, Nigeria
Authors: Charity Maduakor, Uzoamaka , Deborah Okolie, Chidimma , Philip Udoh, Iniekong , Felicia Onyemelukwe, Ngozi
Published: May 2022

Background: Extended -Spectrum Beta- Lactamases (ESBLs) are enzymes that confer resistance to a wide range of β-lactam antibiotics, including penicillins, third-generation cephalosporins, and aztreonam, but not to cephamycins or carbapenems, and are blocked by beta-lactamase inhibitors.

Aim: To evaluate the antimicrobial susceptibility profiles of Escherichia coli and Klebsiella pneumoniae and to determine the prevalence of ESBL-producing Escherichia coli and Klebsiella pneumoniae isolates from the hospital and environmental samples.

Methodology: The study was conducted from October 2020 to June 2021 in the Microbiological Laboratory of the University of Nigeria Teaching Hospital Ituku-Ozalla, Enugu. A total of 150 non-duplicate bacteria isolates were recovered from urine, wound swab, high vaginal swab, stool, sputum, and environmental sources. Isolates were identified and characterized using standard microbiological protocols. Antimicrobial susceptibility was performed using the Kirby-Bauer disc diffusion procedure. Phenotypic detection of ESBL production was determined using Double Disc Synergy Tvest.

Results: E. coli isolates from hospital samples were highly resistant to cefuroxime (100 %), cefixime (100 %) augmentin (100%), ciprofloxacin (91%), and cefotaxime(86.6%). However, nitrofurantoin and imipenem were highly potent 80.6 % and 76.1% respectively. Among the 67 strains of E. coli from hospital samples, 32(47.8%) were found to be ESBL producers. Of the 60 Klebsiella pneumoniae hospital isolates tested, 27(45%) were found to be ESBL-producers. Of the 18 strains of E. coli from environmental isolates, 12(66.7%) were found to be ESBL producers. Out of only five Klebsiella pneumoniae from environmental samples tested, 4(80%) were found to be ESBL producers. A total prevalence of 75(50%) ESBL producers from the 150 isolates were found.

Conclusion: The findings of this study showed an alarming rate of 50% ESBL-producing E. coli and Klebsiella pneumoniae in Enugu Metropolis, Nigeria with a high antimicrobial resistance in both ESBL and non-ESBL-producing isolates.
Quality of References Transcription of Theses at the Faculty of Medicine of Setif - Algeria
Authors: Adjiri Djamila , Laouamri Slimane
Published: May 2022

A fundamental principle of the scientific approach is to justify the main precise facts, stated during the writing of the thesis by scientific, professional and popularization documents. Aim is to contribute to the improvement of the quality of the scientific medical writing of the theses Faculty of Medicine of Setif, in particular the references transcription. Its a comparative study “before – after” a training session on the quality of the scientific medical writing of 120 theses at the faculty of medicine during the two academic years 2014 - 2015 et 2015 -2016. The references transcription was more correct for the pharmacy department. Transcription anomalies were significantly less frequent and the proportion of theses with a correct chapter title was significantly for times greater (OR = 4.0; 95% CI = 1.4–11.2). The same result for titer was observed for the second year (OR = 10.5; 95% CI = 3.4–32.1), but with no significant difference for the number of transcription abnormalities. The insufficient level of knowledge of techniques of scientific medical writing show that the usefulness of training sessions is indisputable for improving the quality of scientific texts and promoting publications.
Incidence of Difficult Intubation in Tmj Ankylosis Patients in University Setting
Authors: Shathviha P. Chithambara , John Rubin S.
Published: May 2022

Introduction:  A fusion of the mandibular condyle with the base of the skull causes ankylosis of the temporomandibular joint (TMJ), which results in a lack of joint movement. The anesthesiologist is concerned about prolonged temporomandibular joint ankylosis because of the restricted airway, which makes intubation difficult. Despite the fact that TMJ ankylosis is a well-known risk factor for difficult airway management, the strategies used are based on the anesthesiologists' skill. It's never easy intubating a patient with temporomandibular joint ankylosis. The purpose of this study was to see how common problematic intubation was in TMJ ankylosis patients.

Aim of the Study: The aim of the present study was to evaluate the incidence of difficult intubation in TMJ ankylosis patients.

Materials and Methods: Among the overall data of patients attending Saveetha Dental College, a retrospective analysis of all the cases (patients who underwent TMJ ankylosis surgery) was extracted. Excel spreadsheets were used to enter the data. SPSS software version 19 was used to analyse the data collected. The data were statistically evaluated using the Chi square test.

Results: In this study, it was discovered that the incidence of difficult intubation in TMJ ankylosis surgery was higher in the age group of 5-18 years than in the other age groups. Intubation in children is tough. The chi square test resulted in statistically significant findings (p<0.005).

Conclusion: Nasal intubation and fiberoptic intubation were the most common modes of intubation used in TMJ ankylosis surgery, according to the results of this small sample retrospective analysis. The difficulty of intubation was increased in the paediatric age group (5-18 years).
Lung Cancer: Solitary Pulmonary Nodule
Authors: Alakkad Ashraf , Chelal Aref , Aitchison James
Published: May 2022

A 55-year old, middle-aged man, known for hypertension and dyslipidemia, presented to the OPD with complaints of fever along with a mild dry cough. There was no shortness of breath or chest pain associated with the patient’s complaints. Therefore, as a seemingly obvious diagnosis, he was suspected of having a COVID-19 infection.  

The man has a positive smoking history of approximately 20 cigarettes per day for 25 years. However, his COVID-19 PCR tests provided two negative results. His chest X-ray was also unremarkable. Apart from some abnormalities in his laboratory analyses, which have been discussed in detail in the coming sections, there seemed to be nothing unusual or out of place with the patient.

However, when a CT scan without contrast was ordered for the patient, the report showed a mass that was approximately 23 x 21 x 16 mm in size. The mass had a soft, tissue-like consistency. It also appeared to have irregular, lobulated margins. This entire mass was seen to be present in the anterior segment of the upper lobe of the left lung.

Apart from this mass, no COVID-19-related consolidations or signs of respiratory distress were seen in this patient.

When the mass was confirmed, a needle-core biopsy was done to find out the nature of it. The biopsy report confirmed that the mass was indeed a moderate-to-poorly differentiated non-small cell carcinoma of the lung, which was consistent with adenocarcinoma with sarcomatoid features.  All these aspects of the tumor, with radiological evidence, have been discussed below.

The patient is being supportively managed as of now and is also being kept on a follow-up schedule.

What's worth mentioning, however, is that despite such minor symptoms, the underlying problem could still be serious. If the patient had not gone for an X-ray or CT for their suspected COVID-19 abnormalities, then their case would not have come to a diagnosis and it would have eventually taken a turn for the worse. The whole case, along with the findings and the patient response has been discussed throughout this paper.
Effect of Tax Revenues on the Economic Development of Nigeria
Authors: Akintola S. K. , Omotola A. A. , Oyinbodunmi B. M. , Akinyemi E. K.
Published: May 2022

The main objective of this study is to examine empirically the effect of tax revenues on the economic development of Nigeria, judging its impact on the relationship between tax revenue and economic growth. Data was sourced from CBN statistical bulletin and the World Bank data. A multiple regression anal is was used for the analysis of the data which would consist of a fusion between the dimensions of time (time series). A quantitative research approach was used to analyze the regression results. Consequently, the findings from the study showed that custom and excise duties, companies income tax, petroleum profit tax, and value-added tax have a significant combined effect on gross domestics product in Nigeria. Similarly, results show that custom and excise duties (B = . 0.117, t=0.031948, p>0.05) and companies income tax (B = 0.539657, t = 2.2215895, p>0.05), petroleum profit tax (B = 0.103431, t = 2.370469, p>0.05), positive effect on GDP and have insignificant effect on gross domestics product, whereas cc (B=-0.452577, t=-0.836510, p>0.05) negative effect on gross domestics product but have insignificant effect on gross domestics product in Nigeria. It was concluded that tax revenue has an effect on the economic development in Nigeria. It was recommended that the government established a long-term goal through investment in infrastructural development.
Whether is Flood Doom or Boon for Kaziranga National Park of Assam, India?
Authors: Hira Bichitra
Published: May 2022

The Kaziranga National Park of Assam is located in the floodplain ecosystem of the Brahmaputra River and hence the flood is the annual feature of the park. Amidst of it, the management for survival of the park along with its spectacular thriving is admirable. However, the perennial flood hurts the park at large carrying tragedies of different kinds such as land erosion, siltation of the water bodies, habitat degradation, damage of physical infrastructure, and exacerbate the accidents of the animals on the NH-37 and the poaching of the helpless animals. Conversely, the flood paybacks the park through nourishing and reviving its ecosystem in several ways such as refill the wetlands, refresh grasslands and remove invasive species, on annual basis. These, otherwise, would entail harder job and hence, a huge cost for the park management. Against this backdrop, an attempt has been made to examine to what extent, the flood is a doom for the park, and is a boon in the park through investigating and critically analyzing of the effects of flood on this world famed wildlife venture. Moreover, how the park authority has managed the flood season to mitigate its adverse outcomes has been examined in this academic work.
Assessment of Urban Sprawl, Land Use and Land Cover Changes in Voi Town, Kenya Using Remote Sensing and Landscape Metrics
Authors: Nyongesa Samantha Kahoya , Maghenda Marianne , Siljander Mika
Published: May 2022

Rapid and uncontrolled urbanization is a major issue in both developing and developed countries. Uncontrolled urbanization has resulted to unplanned expansion of residential and commercial areas, informal settlements, housing shortages, and unplanned land use. Understanding and quantifying urban sprawl spatiotemporal patterns is critical for informing the development of appropriate policies for effective and sustainable land use management. Using image classification and spatial metrics, this study examines the changes in Voi town's urban land use/land cover (LULC) between 1999 and 2019. The LULC was mapped using Landsat Thematic Mapper (TM):Landsat Enhanced Thematic Mapper Plus (ETM+):and Landsat Operational Land Imager (OLI) datasets using supervised maximum likelihood classification. A post classification approach was used to detect and assess LULC changes in the study area, while selected spatial metric indices quantified urban sprawl. The results of the change detection analysis revealed that Voi town has been rapidly expanding, with an urban expansion of 187.96 percent from 1999 to 2011, 183.40 percent from 2011 to 2019, and 716.1 percent from 1999 to 2019. In 1999, the built-up area comprised 1.29 percent of the total study area, 3.72 percent in 2011, and 10.53 percent in 2019. Based on spatial metrics analysis, the number of built-up area patches in 1999, 2011, and 2019 was 154, 278, and 526, respectively. An increase in the number of patches indicated fragmentation and the emergence of new built-up areas. 

As a result, city planners will need to plan ahead of time and implement additional measures to deal with the city's future rapid and unprecedented growth.
Recent Developments on Novel Heterocyclic Compounds Thiadiazoles and Heterocyclic Compounds for COVID-19 Targets in Drug Discovery
Authors: Madhavi B. , Sharma G. Veera Raghava
Published: May 2022

This article mainly reviews the recent developments in the synthesis of novel 1,3,4-Thiadiazoles and also recent development of drug molecules for the treatment of COVID-19. The Thiadiazole heterocycle and its derivatives are the most important class of compounds among various heterocyclic compounds due to their wide range of biological activities and pharmaceutical importance. Thiadiazolemoeity exists as a principal structural pharmacopore in the combination of drug categories such as antimicrobial, anti-inﬂammatory, analgesic, antiepileptic, antiviral, antineoplastic, antitubercular agents. In this review article, we have attempted to show various synthetic procedures of thiadiazole derivatives along with their pharmacological activities and also the recent studies on Antiviral targets for the discovery of new drugs to combat Covid19 like viruses.
Effect of Immunoglobulin Y Tablets on Streptococcus Mutans Counts in Adolescents: An in vivo Study
Authors: Singla Poonam , Thomas Abi M. , Dua Kapil K. , Kundra Ruchika
Published: May 2022

Objectives: Streptococcus mutans has been most intimately associated with the initiation and development of carious lesion. Nowadays, the treatment strategies are aimed at either elimination of this bacterium or suppression of its virulence. The search for more efficient and economical techniques, has led to growing interest for the use of egg yolk antibodies (Immunoglobulin Y). This study was conducted to evaluate the microbiological effect of Ig Y tablets on salivary Streptococcus mutans count in adolescents.

Methods: In this randomized controlled clinical trial, 50 adolescents (12–18 years old) were divided into two groups. Group I adolescents were instructed to use fluoridated toothpaste and Group II were instructed to administer S. Mutans specific Immunoglobulin Y chewable tablets for a period of 15 days along with the fluoridated toothpaste.

Results: The findings of this research demonstrated that the tablets containing specific egg yolk antibodies (IgY) against glucosyltransferase of S. mutans exerted a suppressive effect on S. mutans colonization of the oral cavity in healthy adolescents.

Conclusion: These findings indicate that using IgY in the form of tablets is a novel approach and has the advantage of releasing antibodies slowly into the oral cavity. It is thus effective in decreasing the colonization of the S. mutans, and lowering the induction of dental caries.
Evaluation of Change in Knowledge, Attitude and Adoption Regarding Antibiotic Prophylaxis for Infective Endocarditis Before and After Health Education among Dental Interns in a Private Dental Teaching Institution in India
Authors: Srilatha Y. , Shekar B. R. Chandra
Published: May 2022

Background: There was paucity of data regarding updating of 2007 AHA (American Heart Association) guidelines among dentists in India.

Objective: To evaluate change in knowledge, attitude and adoption of AHA (2007) guidelines regarding Antibiotic prophylaxis for Infective endocarditis before and after health education among dental interns in a private dental teaching institution.

Materials and Methods: This was an interventional study conducted among dental interns in a teaching dental institution. Data was obtained using a validated questionnaire that finally had 32 items. Data was obtained by sharing an online link to complete survey. A reminder was also given one week later and participant responses obtained. Each correct response for a question was assigned a score of 1 while incorrect response was scored as zero. Total score was computed for each participant. Health education on AHA 2007 guidelines for antibiotic prophylaxis against infective endocarditis was offered to participants using power point presentation for about 30 -45 minutes on a scheduled day following baseline data collection. Immediately after health education, participants were again requested to fill the same questionnaire used at baseline. Mean knowledge score before and after health education was compared using paired sample t-test.

Results: 74 participants were considered with response rate of 91.4%. Mean knowledge score significantly increased from 11.5 ± 4.3 (Mean ± Standard deviation) at baseline to 22.9 ± 4.2 post intervention (p < 0.001).

Conclusion: Health education intervention was successful in improving knowledge, attitude and adoption of AHA 2007 guidelines for antibiotic prophylaxis against IE among dental interns.
A Pilot Study of the Effects of Ajwa Date Seed Extract in a Diabetic Animal with Parallel Observations on Human Subjects
Authors: Felemban Shifa , Hamouda Asmaa Fathi
Published: May 2022

Background: most diseases are inequality of the antioxidants, pro-oxidants, and failure in resolved inflammation. Diabetes is a metabolic malfunction associated with inflammation and ends with organs failure. Alternative treatments for diabetes include a lifestyle and an anti-inflammatory diet.

Method: we investigated the effects of dietary Ajwa dates seeds extract (AJSO) against alloxan monohydrate-induced biochemical changes. We analyzed the phytochemical components of AJSO with gas chromatography-mass spectrometry and inductively coupled plasma-mass spectrometry. We determined the effects of oral AJSO on biochemical changes caused by alloxan monohydrate in rats. We also observed biochemical changes in human volunteers with or without Ajwa seed as caffeine-free coffee replacements.

Results: the results and outcomes confirmed the improvement in the rats’ biochemical analysis due to AJSO constituents. The treatment of AJSO after alloxan monohydrate injection significantly (p ≤ 0.05) decline the studied parameters NO, MDA, Amyloid A, CRP, and glucose concentrations by 47.2%, 34.8%, 55.6%, 47.4%and 60.0%, respectively, compared to treatment only with alloxan monohydrate. The volunteers treated with Ajwa seed as caffeine-free coffee replacements(group2) showed significant amelioration of inflammatory and diabetes markers as compared to the untreated group1. Group 2 showed a significant decrease in the concentration of serum NO (34.7%), MDA (43.9%), amyloid A (79.6%), CRP (60.9%), HbA1c (33.8%), Troponin T (16.4%), serum total cholesterol (14.2 %), TG (28.1%), LDL-C (6.1%), AST 8.8%, and ALT (11.6%) compared to Group1.

Conclusion: AJSO had a healthy impact by decreasing the levels of amyloid a, c-reactive protein, lipid peroxidation, nitric oxide, and improving diabetes, lipid and liver profiles in both rats and human volunteers. Further long-term investigation of higher numbers and the different types and sexes is needed in progress to confirm and validate the results.
Morphological and Productive Evaluation of Mombasa Grass as a Function of Phosphate, Nitrogen and Biostimulant Application
Authors: Nunes Bruno Henrique di Napoli , Teixeira Igor Ricardo Barbosa , Gomes César Henrique Borges , Barros Daniella Inácio , Quirino Mariana Senna , Nunes Helber Veras , Libório Ricardo Alencar , Sales Paulo Victor Gomes , Oliveira Liomar Borges de , Sá Luis Fernando Pereira de , Alves Caíque Rodrigues , Barbosa Geovana Rodrigues , Ribeiro Fred Wallison Gomes
Published: May 2022

Nitrogen when applied to the surface, suffers losses by volatilization. Therefore, one of the ways to reduce this loss is to use substances that delay the hydrolysis of NH3. The objective of this study was to evaluate the physiological characteristics of Mombasa grass as a function of nitrogen sources associated or not with volatilization inhibitors (ASP4) and nitrification (CTN). The experiment was conducted in a greenhouse, UFT - Gurupi, in DBC, with six treatments and five replications, being: SN1 - Sulfammo without ASP4; SN3 - Sulfammo + 6kg/ton of ASP4; NC1 - Sulfammo + CTN without ASP4; NC3 - Sulfammo + CTN + 6kg/ton of ASP4, URE - Urea and control without nitrogen. It is note point that all treatments received 100 kg ha-1 of N. The following parameters were evaluated: Chlorophyll A, Chlorophyll B, Total Chlorophyll, internal CO2 concentration, transpiration rate, stomatic conductance, CO2 assimilation rates, water use efficiency, and instantaneous efficiency of ribulose enzyme (RUBI) carboxylation Data were analyzed by MANOVA, using the main component technique (PCA) using the R® 3.5 software. According to the PCA scores, the productive characteristics are CloB; CloA; CloTO. ASSI, RUBI showed the highest variations, all positive, both in PC1 and PC2. The treatments that most influenced the characteristics were NC1 and NC3, demonstrating an inverse tendency to the controls. Crop development was significantly influenced by urea and sources with and without inhibitors.
Chronic Infections among University Students: A Review
Authors: Mwangi Wangui Patrick , Koech Julius , Anapapa Ayubu , Ingado Diana
Published: May 2022

The percentage of university students currently nursing chronic infections/diseases is alarming, and for a long time, these students are ever thought to be healthy. However, research shows otherwise and management of students’ health should be recognized and efforts be directed towards the same. This paper aimed to review the work done by other researchers concerning university students when it comes to chronic diseases and their health, make general comments and emphasize the need to have stakeholders focus on university students in terms of acquiring the right and modern technology meet for dealing with the elephant in the room. About 25 published papers were selected from the internet as they came across and a summary was made from each on what the researchers found concerning the university students’ health and chronic diseases. It was found that no researcher didn’t find unhealthy students and up to 30% of the students can be found infected in a given university. All concluded that the health of the students is deteriorating with time. Therefore, there is a need for stakeholders such as university managements, governments, non-governmental organizations among others to deal with the situation before it’s too late. University students are the next-immediate workforce and their health should not be left to fate. Once this workforce is maimed, there shall be a big problem in the future when things slip out of hand.
Evaluation of QA software system analysis for the static picket fence test
Authors: Boudet Julien , Aubignac Léone , Beneux Amandine , Mazoyer Frédéric , Bessieres Igor
Published: May 2022

Intensity modulation treatments are widely used in radiotherapy because of many known advantages. In this context, the picket fence test (PF) is a relevant test to check the Multileaf Collimator (MLC) performances. So this work compares and evaluates three analysis platforms for the PF used routinely by three different institutions. This study covers two linear accelerators (Linac) with two MLC types, a Millenium 120 MLC and Millenium 120 High Definition MLC respectively on a Varian Truebeam and Truebeam STx. Both linacs include an As 1200 portal imager (EPID). From a reference PF plan, MLC errors have been introduced to modify the slits in position or width (shifts from 0.1 to 0.5 mm on one or both banks). Then errors have been defined on the EPID to investigate detection system deviations (signal sensitivity and position variations). Finally, 110 DICOM‐RT images have been generated and analyzed by each software system. All software systems have shown good performances to quantify the position errors, even though the leaf pair identifications can be wrong in some cases regarding the analysis method considered. The slit width measurement (not calculated by all software systems) has shown good sensitivity, but some quantification difficulties have been highlighted regardless of the analysis method used. Linked to the expected accuracy of the PF test, the imager variations have demonstrated considerable influence in the results. Differences in the results and the analysis methods have been pointed out for each software system. The results can be helpful to optimize the settings of each analysis software system depending on expectations and treatment modalities of each institution.
Finger pointing to self‐manage cognitive load in learning from split‐attention examples
Authors: Zhang Shirong , de Koning Bjorn B. , Paas Fred
Published: May 2022

We investigated whether finger pointing can be used as a cognitive load self‐management strategy when learning from split‐attention examples. We expected that pointing would reduce cognitive load and enhance learning performance. In a guided self‐management phase, 122 university students studied a split‐attention example under three pointing conditions (i.e., no pointing, one‐handed pointing, two‐handed pointing) or an integrated example without pointing. In the subsequent unguided self‐management phase, all students studied a new split‐attention example without pointing instructions. Results on retention and comprehension tests and self‐ratings of cognitive load after studying each split‐attention example revealed no differences between conditions. An exploratory analysis of pointing movements in the unguided self‐management phase revealed that participants who frequently pointed outperformed those who barely pointed on the comprehension test in this phase. Our findings provide some suggestive evidence for the effectiveness of pointing as a self‐management strategy in the learning from split‐attention examples.
Constructing Highly Conductive and Thermomechanical Stable Quasi‐Solid Electrolytes by Self‐Polymerization of Liquid Electrolytes within Porous Polyimide Nanofiber Films
Authors: Huang Yue , Liu Shujie , Chen Qiaojing , Jiao Kejin , Ding Bin , Yan Jianhua
Published: May 2022

Solid electrolytes are being considered as an effective solution to replace liquid ones for building safer batteries, but they suffer either low ionic conductivity or large contact ohmic impedance. Here, a highly conductive and thermomechanically stable quasi‐solid electrolytes (QSE) by self‐polymerization of a commercially available liquid electrolytes (1,3‐dioxolane (DOL), 1,2‐dimethoxyethane (DME), lithium trifluoromethane sulfonimide (LiTFSI) and LiPF6) at room temperature in a porous polyimide nanofiber film are reported. LiPF6 initiates the ring‐opening reaction of DOL and LiTFSI promotes the self‐polymerization to form poly‐DOL (PDOL), while the plasticizer of DME solidifies the PDOL. On the other hand, polyimide has a great affinity with PDOL that facilitates to form stable QSE network. As a result, the QSE film shows a high room‐temperature ionic conductivity of 2.9 × 10−3 S cm−1, a high mechanical strength of 31 MPa, and high heat resistance to 160 °C. The LiFePO4||QSE||Li batteries with a high cathode loading of ≈18.7 mg cm−2 show great cycling performance and stable electrode/electrolyte interfaces at a high current rate of 0.5 C with a capacity retention of 91.8% over 200 cycles at room temperature.
Graphene Membranes for Multi‐Dimensional Electron Microscopy Imaging: Preparation, Application, and Prospect
Authors: Gao Xiaoyin , Zheng Liming , Yao Yating , Peng Hailin
Published: May 2022

Technological breakthrough in electron microscopy (EM) has started a resolution revolution in EM imaging. Nowadays, the promotion of resolution demands a robust background‐noise‐free EM support for specimen preparation, which is a primary bottleneck of high‐resolution EM imaging. Owing to the atomic thickness and excellent physical properties, graphene has attracted widespread attention in the EM field to achieve high‐resolution multi‐dimensional imaging. However, it is still challenging to prepare high‐quality suspended graphene membranes. Problems like breakage, contamination and wrinkling reduce the quality of suspended graphene membranes, which inhibit their wide and killer applications in EM imaging. In this review, suspended graphene membranes are looked deeply into for multi‐dimensional EM imaging. This study begins with a brief introduction to EM development, followed by a discussion of the synthesis of high‐quality graphene. Then it summarizes various approaches to produce suspended graphene membranes and their killer applications in multi‐dimensional EM characterization, including high‐resolution 2D imaging, cryo‐EM 3D reconstruction, and 4D in situ liquid EM. Based on current achievements, the prospects of graphene membranes for more cutting‐edge applications are finally proposed.
In Situ Anchoring Massive Isolated Pt Atoms at Cationic Vacancies of α‐NixFe1‐x(OH)2 to Regulate the Electronic Structure for Overall Water Splitting
Authors: Wang Liming , Zhang Lili , Ma Wei , Wan Hao , Zhang Xinjie , Zhang Xu , Jiang Suyu , Zheng Jin You , Zhou Zhen
Published: May 2022

Rational design and preparation of single‐atom catalysts provide a promising strategy to significantly improve the electrocatalytic activity for water splitting. In particular, single atoms anchored at cationic vacancies can enhance the stability of the catalysts and improve reaction kinetics. In this work, Pt single atoms are loaded at layered α‐Ni2/3Fe1/3(OH)2 by oxidizing Fe2+ with H2PtCl6, and specifically, Pt atoms are anchored at in situ generated iron cationic vacancies during the process, resulting in stabilized Pt single atoms in the surface of α‐Ni2/3Fe1/3(OH)2 with the maximum loading of ≈6.15 wt%. The Pt single atoms not only act as active sites for hydrogen evolution reaction but also regulate the electronic structure of NiFe hydroxides and activate Ni atoms adjacent to Pt for oxygen evolution reaction. Therefore, the water‐splitting electrolyzer assembled with such a bifunctional catalyst shows a smaller overpotential than that with RuO2 and 20 wt% Pt/C catalysts as the anode and cathode, respectively, and efficient solar‐to‐hydrogen conversion. The results demonstrate the practical application of single‐atom Pt catalysts with low cost, large loading, and facile preparation route.
High‐Temperature Flexible Nanocomposites with Ultra‐High Energy Storage Density by Nanostructured MgO Fillers
Authors: Wang Pengjian , Guo Yan , Zhou Di , Li Da , Pang Lixia , Liu Wenfeng , Su Jinzhan , Shi Zhongqi , Sun Shikuan
Published: May 2022

High‐temperature performance is critical to the dielectric polymer capacitors used in environment electronic and high‐power applications. Here, the authors report a composite comprising polyimide (PI) dielectric polymers blended with high‐insulation magnesium oxide (MgO) nano‐filler that exhibits high breakdown strength, wide temperature range, and low dielectric loss. However, most dielectric polymers possess excellent energy storage properties at room temperature and cannot be used at high temperatures above 100 °C. Polyimide dielectric nanocomposites prepared by in situ polymerization, which are composed of easily prepared MgO fillers, have different morphologies, such as nanoparticles (0D), nanowires (1D), and nanoplates (2D). The experimental results show that the insulation behavior and breakdown strength of polymer composites are closely related to the morphology of MgO fillers, and the rationality of this conclusion is further proved by finite‐element simulation results. The polymer composites containing ultra‐low content (0.5 vol%) MgO nanosheets produce an ultra‐high capacitance performance, that is, the discharge energy density is 4.78 J cm−3 at 150 °C, which is significantly better than the most reported dielectric polymers and nanocomposites.
Protein‐Mimicking Nanoparticles in Biosystems
Authors: Ji Xiaoyuan , Li Qian , Song Haiyun , Fan Chunhai
Published: May 2022

Proteins are essential elements for almost all life activities. The emergence of nanotechnology offers innovative strategies to create a diversity of nanoparticles (NPs) with intrinsic capacities of mimicking the functions of proteins. These artificial mimics are produced in a cost‐efficient and controllable manner, with their protein‐mimicking performances comparable or superior to those of natural proteins. Moreover, they can be endowed with additional functionalities that are absent in natural proteins, such as cargo loading, active targeting, membrane penetrating, and multistimuli responding. Therefore, protein‐mimicking NPs have been utilized more and more often in biosystems for a wide range of applications including detection, imaging, diagnosis, and therapy. To highlight recent progress in this broad field, herein, representative protein‐mimicking NPs that fall into one of the four distinct categories are summarized: mimics of enzymes (nanozymes), mimics of fluorescent proteins, NPs with high affinity binding to specific proteins or DNA sequences, and mimics of protein scaffolds. This review covers their subclassifications, characteristic features, functioning mechanisms, as well as the extensive exploitation of their great potential for biological and biomedical purposes. Finally, the challenges and prospects in future development of protein‐mimicking NPs are discussed.
Ultrasoft Porous 3D Conductive Dry Electrodes for Electrophysiological Sensing and Myoelectric Control
Authors: Yao Shanshan , Zhou Weixin , Hinson Robert , Dong Penghao , Wu Shuang , Ives Jasmine , Hu Xiaogang , Huang He , Zhu Yong
Published: May 2022

Biopotential electrodes have found broad applications in health monitoring, human–machine interactions, and rehabilitation. This article reports the fabrication and applications of ultrasoft breathable dry electrodes that can address several challenges for their long‐term wearable applications—skin compatibility, wearability, and long‐term stability. The proposed electrodes rely on porous and conductive silver nanowire‐based nanocomposites as the robust mechanical and electrical interface. The highly conductive and conformable structure eliminates the necessity of conductive gel while establishing a sufficiently low electrode–skin impedance for high‐fidelity electrophysiological sensing. The introduction of gas‐permeable structures via a simple and scalable method based on sacrificial templates improves breathability and skin compatibility for applications requiring long‐term skin contact. Such conformable and breathable dry electrodes allow for efficient and unobtrusive monitoring of heart, muscle, and brain activities. In addition, based on the muscle activities captured by the electrodes and a musculoskeletal model, electromyogram‐based neural–machine interfaces are realized, illustrating the great potential for prosthesis control, neurorehabilitation, and virtual reality.
A Biodegradable Hybrid Micro/Nano Conductive Zinc Paste for Paper‐Based Flexible Bioelectronics
Authors: Zareei Amin , Selvamani Vidhya , Gopalakrishnan Sarath , Kadian Sachin , Maruthamuthu Murali Kannan , He Zihao , Nguyen Juliane , Wang Haiyan , Rahimi Rahim
Published: May 2022

Paper‐based electronics are emerging as a new class of technology with broad areas of application. Despite several efforts to fabricate new types of flexible electronic devices by screen printing of conductive paste, many of them are often nonbiodegradable, toxic, and expensive, limiting their practical use in bioresorbable paper‐based electronics. To address this need, a highly conductive and biodegradable bimodal conductive paste is developed using cost‐effective zinc‐based micro and nanoparticles with a facile low‐temperature sintering process compatible with paper substrates. The two‐step sintering process involves the removal of the insulating zinc oxide layer by spray coating acetic acid followed by a heat press sintering process to ensure the formation of highly packed and continuous metallic traces. The required conditions for the heat press sintering process are systematically studied using electrical, optical, and mechanical characterization techniques. The results of these investigations revealed an ultra‐packed microstructure with high electrical conductivity (0.5 × 105 S m−1) and low oxide content that is obtained with a heat press sintering setting of 220 °C for 60 s. Finally, as a proof of concept, the conductive paste with an optimized sintering process is used to fabricate a wearable wireless heater for remote‐controlled release of therapeutics. The controlled delivery of the system is validated in the practical and on‐demand delivery of antibiotics for eradicating commonly found bacteria such as Staphylococcus aureus in dermal wound infections. The biocompatibility of all the materials and manufacturing process is validated by NIH/3T3 fibroblast cells via MTT assay and live/dead staining.
Immobilized Molecules’ Impact on the Efficacy of Nanocarbon Organic Sensors for Ultralow Dopamine Detection in Biofluids
Authors: Suriyaprakash Jagadeesh , Gupta Neeraj , Shan Lianwei , Wu Lijun
Published: May 2022

Dopamine (DA) is a key neurotransmitter that regulates many behaviors and physical functions in the human body. Therefore, there is a significant technological demand for an affordable point‐of‐care (POC) device to monitor low DA levels up to 10−12min human biofluids. This can be achieved if the underlying interaction mechanism of analyte– materials–transduction is tuned at the molecular level in the carbon‐based organic sensors, and such knowledge is deficient in current literature. Herein, the one‐step facile molecular engineering approach is adopted to develop three organic‐based sensors consisting of different arylamines (hydroxyl/carboxyl/sulfonate) anchored to the surface of 2D‐reduced graphene oxide (rGO). The impact of immobilized molecules on their efficacy is studied in detail by experimental and computational approaches. The carboxyl–arylamine attached to rGO surface outperforms others, resulting in the detection of DA up to 10 × 10−12m(at a larger linear range of 10−10–10−4m) in the presence of interferents. As a proof of concept, a POC device is designed and evaluated in serum, artificial sweat, and urine samples, exhibiting exceptional results. The rational understanding and fundamental science behind the tunable features of carbon‐based organic sensors presented in this work will enable the development of innovative probes for detecting neurotransmitters and related biomolecules.
Na‐Ion Battery with Graphite Anode and Na3V2(PO4)3 Cathode via Solvent‐Co‐Intercalation Process
Authors: Subramanyan Krishnan , Akshay Manohar , Lee Yun‐Sung , Aravindan Vanchiappan
Published: May 2022

Spent Li‐ion batteries are efficiently recycled by extracting and reusing the anode active material, graphite, through a simple yet effective and scalable technique as anode for the sodium‐ion battery (SIB). The recovered graphite (RG) half‐cell rendered a capacity of >120 mAh g−1 via the solvent‐co‐intercalation process. An in situ impedance is performed to assess the robustness of the electrolyte for the extended cycling. The performance of RG is evaluated in a full‐cell with carbon‐coated Na3V2(PO4)3 cathode, which exhibits capacity retention of 78% after 100 cycles. In addition, a temperature dependence performance of the full‐cell is studied from −10 to 40 °C, where it exhibits outstanding low‐temperature performance. The full‐cell provides an energy density of 78 Wh kg−1 at ambient temperature conditions. Recovery of active materials for SIB will drive down the cost/kWh and act as a green technology to dispose of spent Li‐ion batteries.
Dynamic Interplay between Structural Variations and 3D Genome Organization in Pancreatic Cancer
Authors: Du Yongxing , Gu Zongting , Li Zongze , Yuan Zan , Zhao Yue , Zheng Xiaohao , Bo Xiaochen , Chen Hebing , Wang Chengfeng
Published: May 2022

Structural variations (SVs) are the greatest source of variations in the genome and can lead to oncogenesis. However, the identification and interpretation of SVs in human cancer remain technologically challenging. Here, long‐read sequencing is first employed to depict the signatures of structural variations in carcinogenesis of human pancreatic ductal epithelium. Then widespread reprogramming of the 3D chromatin architecture is revealed by an in situ Hi‐C technique. Integrative analyses indicate that the distribution pattern of SVs among the 3D genome is highly cell‐type specific and the bulk remodeling effects of SVs in the chromatin organization partly depend on intercellular genomic heterogeneity. Meanwhile, contact domains tend to minimize these disrupting effects of SVs within local adjacent genomic regions to maintain overall stability. Notably, complex genomic rearrangements involving two key driver genes CDKN2A and SMAD4 are identified, and their influence on the expression of oncogenes MIR31HG, MYO5B, etc., are further elucidated from both a linear view and 3D perspective. Overall, this work provides a genome‐wide resource and highlights the impact, complexity, and dynamicity of the interplay between structural variations and high‐order chromatin organization, which expands the current understanding of the pathogenesis of SVs in human cancer.
Soil health within transitions from irrigation to limited irrigation and dryland management
Authors: Bhandari Krishna B. , Acosta‐Martínez Veronica , Pérez‐Guzmán Lumarie , West Charles P.
Published: May 2022

The decline in groundwater supply in the Texas High Plains is forcing some growers to convert center‐pivot irrigated cropland to dryland production. Transitioning toward reduced water input can lead to declines in soil health. We assessed short‐term changes in soil health indicators in two transition scenarios: (a) from high irrigation method to low irrigation method (center pivot to subsurface drip) and (b) from high irrigation method to dryland (center pivot to dryland), in comparison to continuous center‐pivot management. We monitored changes in chemical and biological indicators in four fields for each transition scenario and in three pivot‐irrigated fields. There were declines in soil water content, potassium (K), sodium (Na), and soil organic carbon with transition from irrigation to reduced irrigation and dryland. Severe drought in the final year revealed reduced amounts of multi‐enzyme activities, total ester‐linked fatty acid methyl ester (EL‐FAME), and total fungi. Transitioning to low water‐input management in this environment complicates efforts to maintain microbial components of soil health. Longer‐term comparisons are needed to detect slow changes in soil health indicators on producers’ fields.
Boosted Charge‐Carrier Transport in Triple‐Cation Perovskites by Ultrasonic Vibration Post Treatment
Authors: Wang Yuzhuo , Ahmadian‐Yazdi Mohammad‐Reza , Ni Yangyang , Jiang Yexin , Eslamian Morteza , Jin Zuanming , Chen Qianli
Published: May 2022

Ultrasonic vibration imposed on the substrate of a drying perovskite solution film has previously been proposed as a nearly annealing‐free method to improve film quality and thus the photovoltaic performance for perovskite solar cells. However, an in‐depth understanding of the underlying mechanism of the improved film quality via ultrasonic vibration is still lacking. In this work, the effects of substrate vibration post treatment on the carrier lifetime and mobility are studied in triple‐cation perovskite films. With 80 s of annealing‐free vibration, the perovskite film demonstrates much stronger photoluminescence intensity and much longer carrier lifetime up to 2.634 µs, 2 orders of magnitude longer than that of the thermal annealed films. Optical pump terahertz probe spectroscopy reveals that the charge‐carrier mobility increases to 121 ± 44 cm2 V−1 s−1 when subjected to 80 s vibration followed by annealing. Such mobility is about 80 ± 40 cm2 V−1 s−1 higher than that of other polycrystalline organic–inorganic hybrid perovskite thin films of similar composition. The diffusion length is improved to nearly 1.5 times. The new understanding on the vibration‐induced charge‐carrier transport properties paves the way for the application of ultrasonic vibration toward the performance improvement of perovskite‐based electronic devices.
Valuing an agricultural technology startup using real options
Authors: Wilson William W. , Vetsch Lee , Bullock David W.
Published: May 2022

There has been substantial growth in investments for startup firms to develop agricultural technology. Although investing in startups can produce significant returns, the risk of failure is high, and the commercial strategies are largely unknown. Traditional valuation methodologies, such as discounted cash flow (DCF) and multiples, are not well suited for startups. Real options provide a methodology to quantify the value of growth opportunities and managerial flexibility, two critical features of startups. This study develops a model that integrates decision trees and a stochastic binomial lattice to quantify the value of growth opportunities and managerial flexibility in a prerevenue AgTech startup. Utilizing a binomial lattice and decision trees allows for the quantification of private and market risk. The result is a valuation that quantifies the upside optionality that other methodologies disregard. [EconLit Citations: O32, O34, Q140, Q16, C6, G11].
Chemoenzymatic Cascades for the Enantioselective Synthesis of β‐Hydroxysulfides Bearing a Stereocentre at the C−O or C−S Bond by Ketoreductases
Authors: Zhao Fei , Lauder Kate , Liu Siyu , Finnigan James D. , Charnock Simon B. R. , Charnock Simon J. , Castagnolo Daniele
Published: May 2022

Chiral β‐hydroxysulfides are an important class of organic compounds which find broad application in organic and pharmaceutical chemistry. Herein we describe the development of novel biocatalytic and chemoenzymatic methods for the enantioselective synthesis of β‐hydroxysulfides by exploiting ketoreductase (KRED) enzymes. Four KREDs were discovered from a pool of 384 enzymes identified and isolated through a metagenomic approach. KRED311 and KRED349 catalysed the synthesis of β‐hydroxysulfides bearing a stereocentre at the C−O bond with opposite absolute configurations and excellent ee values by novel chemoenzymatic and biocatalytic‐chemical‐biocatalytic (bio‐chem‐bio) cascades starting from commercially available thiophenols/thiols and α‐haloketones/alcohols. KRED253 and KRED384 catalysed the enantioselective synthesis of β‐hydroxysulfides bearing a stereocentre at the C−S bond with opposite enantioselectivities by dynamic kinetic resolution (DKR) of racemic α‐thioaldehydes.
Regioselective Magnesiations of Fluorinated Arenes and Heteroarenes Using Magnesium‐bis‐Diisopropylamide (MBDA) in Hydrocarbons
Authors: Hess Andreas , Alandini Nurtalya , Guersoy Yusuf C. , Knochel Paul
Published: May 2022

We report a convenient preparation of a new and storable magnesium amide (iPr2N)2Mg (magnesium‐bis‐diisopropylamide; MBDA) which proved to be especially suitable for the non‐cryogenic magnesiation of fluoro‐substituted arenes and heteroarenes providing arylmagnesium amides (ArMgDA) orbis‐heteroaryl magnesiums (HetAr)2Mg in hydrocarbons. Further reactions with electrophiles (aldehydes, ketones, allylic bromides, aryl halides (Negishi cross‐coupling)) furnished a range of polyfunctional fluoro‐substituted unsaturated building blocks. Several postfunctionalizations were described as well as NMR‐studies confirming the dimeric structure of the base.