bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effects of Silicon Dioxide Nanoparticles and Zinc Oxide Nanoparticles on Waste Land soil Bacterial and Fungal Isolates
Authors: Lakshmi P. Jayashree , Selvi K. Vanmathi
Published: December 2021

Objective: Different bacterial and fungal isolates were collected from the wasteland municipality site, Tambaram. The antimicrobial activity of two types of nanoparticles ZnO & SiO2 [Zinc oxide and Silicon dioxide] against several types of Gram-negative bacteria and fungi was investigated in this work.

Methods: P. aeruginosa, B. subtilis, Penicillium oxalicum and Aspergillus fumigatus were isolated from 5 soil samples taken from three sites of Tambaram Municipality wasteland (Chennai). After collecting the samples, we used culturing and biochemical tests to identify the microbes and then used a chemical approach to make ZnO and SiO2 nanoparticles with altered structure and morphological features. Minimum inhibitory concentration (MIC) was used to assess the antibacterial activity of these nanoparticles against various microorganisms.

Results: The best inhibition zone was found in Pseudomonas sps and Bacillus sps growth at concentrations of 10 µg/ml and 5 µg /ml of nano-ZnO, respectively, whereas the lower inhibition zone was found in Penicillium oxalicum and Aspergillus fumigatus at a dosage of 2.5 µg /ml of the same nanoparticle. It was also discovered that no inhibitory zone existed in any of the bacteria and fungi at a concentration of 10 µg /ml nano-SiO2. We found that all of the bacteria and  fungi we tested were completely inhibited at a concentration of 1.25 g/ml nano-ZnO (MIC), with no antibacterial activity below this concentration. When compared to data that showed that all tested bacteria were not completely inhibited even at a concentration of 0.625 g/ml of nano-SiO2.

Conclusion: In comparison to the two nanoparticles (ZnO and SiO2), nano-ZnO outperformed nano-SiO2 in inhibiting most bacteria and fungi at the quantities tested in wasteland soil.
Effective Response to DPP-4 Inhibitors in Patients of COVID – 19 Triggered Uncontrolled Type 2 DM – A Case Report
Authors: Dahiwele Akshay , Patil Shailesh , Zilate Sarju , Salankar Harsh , Rode Sonali
Published: December 2021

Introduction: A bidirectional relationship exist between the COVID -19 diagnosed & recovered patient and Type 2 Diabetes Mellitus. As per the various article available in public domain it has been proved that entry of COVID – 19 virus can lead to a series of pathological changes into a patient’s body which may lead to the development of insulin resistance and damage to the pancreas.

The patient in our case was a COVID – 19 survivor which was diagnosed with type 2 DM during the treatment. The patient was started with the Glargine insulin when she was undergoing her treatment in the hospital for COVID – 19 Symptoms. Her fasting and postprandial blood sugar level was controlled with the insulin. After her discharged she was started with the Metformin 500 mg twice a day but her blood sugar was not controlled with the Metformin monotherapy, so we started with the triple drug combination Metformin + Glimepiride + Pioglitazone. After 1 month of follow-up, it was seen that the blood sugar level was not controlled, so the Pioglitazone was replaced with the DPP-4 inhibitor drug Vildagliptin and again the patient was asked to come for follow-up after 15 days, it was seen in this follow-up that the patients’ blood sugar was dramatically controlled.

Conclusion: COVID – 19 triggered Type 2 DM is the result of cytokine storm develop during the disease. Metformin and DPP – 4 inhibitors reduce the insulin resistance in type 2 diabetes patients and helps to achieve the euglycemic goal of the patient.
Relationship between Uncertainty Tolerance and Acceptance in Postoperative Patients with Cervical Cancer
Authors: Ghaffar Bushra , Shah Muhammad Jahangir , Zaka Marvi
Published: December 2021

Background and Objectives: The main objective of the study is to explore the relationship between uncertainty tolerance and positive acceptance of post-surgical patients with cervical cancer and provide reference opinions for gynecological nurses to carry out targeted health education for patients.

Methods: This cross sectional study was conducted in Nishtar Hospital Multan with the collaboration of BVH and Avicenna Hospital, Lahore during March 2021 to September 2021. The "Uncertainty Tolerance Scale" and "Positive Acceptance Scale" were used to investigate 233 post-operative patients of cervical cancer.

Results: The uncertainty tolerance and acceptance aggressiveness scores were 3.74±0.34 and 1.96±0.20, respectively, with a significant correlation coefficient between uncertainty tolerance and acceptance aggressiveness (r= -0.516, P<0.05).

Conclusion: It is concluded that the uncertainty tolerance and positive acceptance levels of patients after cervical cancer surgery were low and were negatively correlated with each other. The gynecological nurses should consider the patients' uncertainty tolerance post-surgery and develop tailored health education and intervention programs to improve the positive acceptance level of post-surgical patients with cervical cancer.
Dental Anthropology-A Revolutionary Tool in Forensic Science
Authors: Raza Anura Saher , Reche Amit , Chhabra Kumar Gaurav , Madhu Priyanka Paul , Dixit Drishti
Published: December 2021

Dental anthropology is a field of physical anthropology that studies the origin, development, and evolution of anthropoid dentitions, as well as their relationship to social, physical, and cultural factors. Teeth have their own distinct morphology and physiology, which is in stark contrast to the body's genetic structure. Teeth are also unique among the resistant elements of archaeological and fossil remains in that they have been exposed on the body's surface throughout their lives. As a result, dental anthropology may be assessed in the mouth cavity of living humans using similar methods to those used for prehistoric relics. As a result, it's no surprise that practising dental surgeons have historically ranked well among dental anthropologists.

This review’s initial purpose is to provide an overview of the morphological and non-morphological properties of animate dentitions that aid in the indirect identification of prehistoric remains and the understanding of their cultural, social, and physical relationships, as well as to assist forensic odontologists with craniofacial identification and skull bone reconstruction.
Hepatitis B, C, and HIV Infections among blood Donors at Several Hospitals in Lahore, Pakistan
Authors: Arshad Shafia , Arif Amina , Ahmad Rafique , Seemab Zeemal , Shaheen Faiqa , Tanveer Rida
Published: December 2021

The study's objectives are to find out the frequency of hepatitis C, B, and HIV infection among blood donors at different hospitals of Lahore; to understand the relationship of demographic risk factors contributing to the positive cases of hepatitis C, B, and HIV. A cross-sectional study with random sampling in which 200 blood donors participated. A questionnaire was used to record the social and personal practices.  A small percentage of blood donors have a history of jaundice. More than one-fourth had undergone surgical intervention, and more than one-third had suffered a needle stick injury. The vast majority had a history of I/V injections/drips, tooth extraction/dental operations, or both. 10.5% of blood donors were Anti-HBV positive, 12.5% were Anti-HCV positive, and 0.5% were HIV positive. Shaving from community barbers should be avoided. In addition, to overcome hepatitis B, C, and HIV transmission, health education programs should be held among blood donors and the general public to prevent them from infection.
Antioxidant, Antimicrobial and Formulation of Borage (Borago officinalis) Seeds Oil and Leaves Extracts as Microemulsion
Authors: Yaghmour Reem , Garajah Marwa , Kayali Ibrahim , Al-Rimawi Fuad
Published: December 2021

Aims: This study aims to investigate antioxidant and antibacterial activities of borage (seeds and leaves) extracts, and to prepare different topical microemulsion formulations using borage oil.

Study Design: Borage seeds and leaves were collected from Hebron -Palestine, then the borage leaves and seeds were prepared for extraction and then extracted with Soxhlet using ethanol. The antimicrobial and antioxidant activity of the extracts were studied, and then Ternary Phase Diagram was constructed using the borage extracts (from seeds and leaves).

Methodology: The seeds were cultivated upon their ripening season in April of 2016 from the Halhul mountains in Hebron/Palestine. Soxhlet method was used to extract borage seeds and leaves oil by using ethanol 95%. A ternary phase diagram was constructed by determining appropriate nonionic surfactant to assess the ability for microemulsion formulation and durability of each system. Tween 80 was found to be more suitable to solubilize each of borage seeds and leaves extracts compared with Tween 20 due to its prominent hydrophobic properties. The antibacterial activity was evaluated for both borage seeds and leaves extracts using a well diffusion method against Staphyloococcus aureus, Escherichia coli, &Candida albicans.

Results: Results showed that the seeds extract has inhibition zone (12 mm) against S. aureus (gram positive bacteria) higher than inhibition zone that leaves extracts exhibited (7.5mm), but no significant effects observed for both extracts against E. coli and C. albicans. In addition, antibacterial activity for microemulsions formulation was measured against S. aureus, E. coli, and C. albicans. Results showed that there is minor activity against S. aureus when compared to PenicillinG and the pure seed oil or leaves extract. In contrast no activity was reported against E. coli and C. albicans. The antioxidant activity was further indicated by the quiet good ability to reduce the FRAP reagent for both extracts with the indication of higher seeds extract activity. This variation is explained by the higher seeds extract content of polyphenol, tocopherol and vitamin C than leaves extract.

Conclusion: Borage seeds and leaves were extracted, and the extracts were showed antimicrobial and antioxidant activity and showed that they can be used in microemulsion using ternary phase diagram.
Comparison of the Hypotension in Lateral Verses Sitting Positions during Induction of Spinal Anaesthesia for Caesarean Section
Authors: Arshed Muhammad , Khatoon Hafiza , Nadeem Kenza , Ali Tahir , Asad Hira , Hussain Shahid
Published: December 2021

Objective: To compare the hypotension in lateral verses sitting positions during induction of spinal anaesthesia for caesarean section.

Study Design: This is a Randomized control trial (RCT) study.

Setting: Study carried out at Department of Anaesthesiology, Surgical Intensive Care Unit and Pain Management, Civil Hospital, Dow University of health sciences Karachi, from December 2018 to June 2019.

Materials and Methods:  All women age 18 to 45 underwent elective caesarian section having ASA I and II, singleton pregnancy on ultrasound with parity ≤3 were enrolled. Patients were randomized to receive spinal anaesthesia in the lateral position (Group L) or the sitting position (Group S) through lottery methods. Using the L3-4 interspace, patients received intrathecal plain bupivacaine, 10mg or 12 mg according to their height, after which they was placed immediately in the supine position with left uterine displacement. Maternal blood pressure was measured with the help of Non-invasive BP apparatus. BP was recorded at baseline then every 5 min till 30 minutes by anesthetist who was unaware of parturient group. Any single or more reading of SBP of <90 mmHg was considered as Hypotension.

Results: Mean age of the patients in lateral group was 31.49 ±10.87 years and mean age of the patients in sitting group was 31.80 ±10.77 years (p-value 0.869). Majority of the patients 35 (62.5%) with hypotension were presented with sitting position. Chi square test was applied and statistically significant difference was observed between groups (p-value 0.012). 

Conclusion: We concluded that less frequency of hypotension was observed when spinal anaesthesia for caesarean section using plain bupivacaine in the lateral position.
Effect of Vata Dosha on Intelligence Quotient and Emotional Quotient
Authors: Sreelekshmi G. , Vaidehi Raole , Raju N. R. Navoday
Published: December 2021

According to Ayurveda the whole life processes are governed by the Tridosha i.e. Vata, Pitta and Kapha. Vata Dosha has been given prime importance because it is the primary force that motivates and mediates other Dosha, Dhatu and Mala for performing their functions in the body. Vata Dosha possesses various Guna. Based on such Guna it performs different Karma in the body. Vata control motor as well as sensory functions. It is a self-generating and self- propagating energy responsible for the regulation of almost all the activities in our body. It should be considered as an invisible force that is recognised through its functions. This paper aims at understanding the effect of Vata Dosha on Intelligence Quotient and Emotional Quotient. The word quotient means amount of a specified quality or characteristic. The characteristics of individuals are developed on the predominance of Dosha during intra-uterine life and it is mentioned in classical textbooks in Prakruti concepts. In the formation and maintenance of Deha Prakruti and Manasa Prakruti the role of Dosha is inevitable. Among the five types of Vata, Prana is responsible for controlling the functions of Buddhi and Manas, while Udana helps in recalling the past experiences.
Knowledge and Attitude towards Vitamin D among Saudi Female university students at Princess Nourah University
Authors: Ramadan Yomna Khaled , Alasgah Sarah Mohammed , Alshammari Amira Saud , Bnfadliah Rima Salman , Aldrees Mashael Abdulmohsin , Alwehibi Fatimah Abdullah
Published: December 2021

Aims: The purpose of this study was to assess the knowledge and attitude towards vitamin D and sunlight exposure among female university students.

Study Design:  Cross Sectional study design.

Place and Duration of Study: The study was conducted among 500 female Saudi students in Princess Nourah Bint Abdulrahman University (PNU).

Methodology: A self-administered questionnaire was used to assess the knowledge about vitamin D sources, health benefits and effects of vitamin D deficiency and assessing the attitude towards vitamin D and sunlight exposure.

Results: The present study recognized that health college students (52.7%) had better knowledge than non-health college students (47.3%). Although PNU students had good knowledge about vitamin D, only 6.0% of them knew the current recommended daily dose. Female students showed good behavior and attitude in terms of high frequency of sunlight exposure daily (34.8%). Educational institutions were the main sources of information about vitamin D (43%). Hot weather (54.8%) and fear of pigmentation (51.2) were the main reasons for limited sunlight exposure among students.

Conclusion: There was a good level of knowledge (52.2%) about vitamin D sources, benefits and effects of vitamin D deficiency among female students. In fact, health college students had better knowledge about vitamin D than non-health college students. Hot weather (54.8%) and fear of pigmentation (51.2%) were the main barriers to sunlight exposure.
Epidemiological Study and Associated Risk Factors for Developing Bacterial Meningitis in Children of Odisha, India
Authors: Khuntia C. P. , Kar S. K. , Dwibedi B.
Published: December 2021

Background: Bacterial meningitis is a leading cause of high childhood transience. It is the foremost cause of fatality in pediatric age group of 0-5 years in India accounting 0.5 to 2.6% of hospital admissions with CFR 16-30%. Based on above scenario, the study was undertaken to address the prevalence, etiology, social determinants of health factors of bacterial meningitis among under five children Odisha, India.

Methods: A cross sectional study comprising of children under five years of age admitted to tertiary care hospital and teaching institutions in Cuttack with suspected clinical diagnosis of bacterial meningitis during April, 2012 to September 2013. About 634 children enrolled into the study after getting appropriate consent from parents or their legal guardians. Lumbar puncture was done and CSF was sent for biochemical analysis, cell counts, staining, culture, latex agglutination test (LAT) and real time polymerase chain reaction (RT PCR).

Results: About 61 children (10.4%) were confirmed with diagnosis of bacterial meningitis by either culture, latex or RT PCR.  Male children (74.7%) were significantly more prone to bacterial meningitis than females (24.3%). The common isolated pathogens were Streptococcus pneumonia, Haemophilus influenza type b, E. coli, Pseudomonas aeruginosa, Klebseilla pneumoniae and Staphylococcus aureus. Streptococcus pneumoniae was observed to be most common pathogen (57.6%) followed by Haemophilus influenzae type b (26.2%). The risk factors analyzed showed statistically significant association (p<0.01) with low household income, mother’s education, overcrowding (more than 3 persons in a single room), smoking and poor ventilation of household.

Conclusion: Strengthening early detection of bacteria meningitis by rapid diagnostic test like LATEX, RT PCR and prompt treatment of emergent case at the household level, improvement in mother’s education and awareness, transportation to local hospital and facility for treatment and care should be utmost priority in the present scenario. It is crucial to assess the burden of bacterial meningitis with its etiology is in this region as  vaccines are yet to be introduced in the child vaccine program.
Uma Análise Sobre o Encaminhamento das Contas dos Municípios do Estado do Rio Grande do Norte no Ano de 2008
Authors: Viana de Souza Fabia Jaiany , Silva Mauricio Corrêa da
Published: December 2021

A consolidação das demonstrações contábeis públicas tem como objetivo permitir a visão global do resultado nacional e a instrumentalização do controle social, através do conhecimento e da disponibilização de agrupamentos do setor público. Esta pesquisa tem o objetivo geral de analisar se os municípios do Estado do Rio Grande do Norte cumpriram o prazo de encaminhamento de suas contas anuais para consolidação das contas públicas, de acordo com o estabelecido no Art. 51 da LRF, no ano de 2008. A metodologia utilizada constituiu-se da pesquisa descritiva, bibliográfica e qualitativa. A coleta de dados foi realizada no sítio da Secretaria do Tesouro Nacional (STN), a fim de obter os prazos das entregas das contas desses municípios. Os resultados revelaram que dos 167 municípios que constituem o Estado do Rio Grande do Norte, apenas 19% entregaram as suas contas anuais no prazo estabelecido no Art. 51 da LRF, 74% enviaram depois do prazo, e, por fim, 7% ainda não tinham encaminhado essas informações para a Secretaria do Tesouro Nacional (STN), até o dia de emissão do relatório utilizado para a coleta de dados da pesquisa.
Pesquisadores em Contabilidade no Brasil: um panorama
Authors: Soares Sandro Vieira , Ebsen Kamille Simas , Pfitscher Elisete Dahmer , Casagrande Maria Denize Henrique
Published: December 2021

Esta pesquisa teve por objetivo analisar o perfil acadêmico dos pesquisadores em Ciências Contábeis no Brasil. A metodologia foi classificada como descritiva quanto aos objetivos, com uma abordagem qualitativa. A amostra foi composta por 53 grupos de pesquisa de modo que a fração amostral foi de aproximadamente ¼ da população. A formação em nível de graduação dos pesquisadores foi identificada predominantemente nas áreas de Contabilidade, Administração, Economia e Direito. A formação em nível de mestrado dos pesquisadores foi principalmente nas áreas de Contabilidade, Administração, Engenharia de Produção e Economia. A maioria dos pesquisadores que compôs a amostra se doutorou na área de Contabilidade em instituições brasileiras, principalmente na Universidade de São Paulo – USP, na Universidade Federal de Santa Catarina – UFSC e na Universidade Federal do Rio de Janeiro - UFRJ. A maioria dos doutorados foi cursada entre os anos de 1996 e 2010. A análise dos pós-doutorados apontou que a maioria foi desenvolvida em instituições estrangeiras, como, por exemplo, a University of Illinois. Já no Brasil as duas instituições mais procuradas foram a Universidade de São Paulo e a Fundação Getúlio Vargas - FGV/SP. A análise apontou também que a maioria deles foi concluída entre 2001 e 2010.
ANÁLISE DOS BALANÇOS SOCIAS DE DUAS EMPRESAS DO SETOR TÊXTIL DE SANTA CATARINA ANÁLISE DOS BALANÇOS SOCIAS DE DUAS EMPRESAS DO SETOR TÊXTIL DE SANTA CATARINA
Authors: Boca Santa Stephane Louise , Pfitscher Elisete Dahmer , Uhlmann Vivian Osmari
Published: December 2021

O setor têxtil é um dos setores importantes de Santa Catarina e as indústrias aqui implantadas, tem demanda a todo Brasil e inclusive ao exterior. Por isso foram escolhidas duas empresas deste setor para fazer uma análise do Balanço Social, visto que hoje se faz cada vez mais necessário investir no meio ambiente e na sociedade. Assim, o objetivo geral deste trabalho é verificar os investimentos nos indicadores sociais internos e externos de duas empresas do ramo têxtil. Como objetivos específicos têm-se realizar análise vertical e horizontal dos indicadores sociais internos e indicadores sociais externos, considerando outros indicadores mencionados. Os dados foram analisados buscando compreender as informações disponibilizadas por meio dos Balanços Sociais das duas empresas, como também uma das empresas respondeu uma entrevista semi-estruturada enviada. Conclui-se que as duas empresas investem em questões sociais e coincidem em alguns indicadores sociais. A empresa A utiliza Balanço Social IBASE, enquanto a empresa B, Balanço Social próprio. Além disso, as empresas demonstram interesses sociais e ambientais, mas não mostram ainda todos os valores monetários dos investimentos.
AUDITORIA CONTÍNUA: TENDÊNCIAS NO CENÁRIO BRASILEIRO
Authors: Reis Claudia Marchioti Nicolau dos , Tostes Fernando Pereira , Duque Andréa Paula Osório
Published: December 2021

O presente estudo objetiva investigar as tendências de pesquisas acadêmicas predominantes no Brasil, na área de Auditoria Contínua, no período de 2006 a 2011, considerando os periódicos brasileiros Qualis Capes A2, B1, B2 e B3. A relevância do estudo consiste em colaborar na identificação da evolução quantitativa e qualitativa da pesquisa em Auditoria Contínua no Brasil. A metodologia utilizada baseou-se em um estudo exploratório e abordagem quanti-qualitativa. Os resultados obtidos contemplando a temática pesquisada apontam que apenas três artigos em periódicos nacionais abordam o assunto Auditoria Contínua, possivelmente justificada pelo desconhecimento do tema ou desinteresse por parte dos auditores e acadêmicos. No entanto, as pesquisas indicam a Auditoria Contínua como tendência de gestão e controle nos negócios devido ao aumento da complexidade dos dados e a preparação para atender aos órgãos reguladores.
FOXO3 regulates a common genomic program in aging and glioblastoma stem cells
Authors: Audesse Amanda J. , Karashchuk Galina , Gardell Zachary A. , Lakis Nelli S. , Maybury‐Lewis Sun Y. , Brown Abigail K. , Leeman Dena S. , Teo Yee Voan , Neretti Nicola , Anthony Douglas C. , Brodsky Alexander S. , Webb Ashley E.
Published: December 2021

Background

Glioblastoma (GBM) is an aggressive, age‐associated malignant glioma that contains populations of cancer stem cells. These glioma stem cells (GSCs) evade therapeutic interventions and repopulate tumors due to their existence in a slowly cycling quiescent state. Although aging is well known to increase cancer initiation, the extent to which the mechanisms supporting GSC tumorigenicity are related to physiological aging remains unknown.

Aims

Here, we investigate the transcriptional mechanisms by which Forkhead Box O3 (FOXO3), a transcriptional regulator that promotes healthy aging, affects GSC function and the extent to which FOXO3 transcriptional networks are dysregulated in aging and GBM.

Methods and results

We performed transcriptome analysis of clinical GBM tumors and observed that high FOXO3 activity is associated with gene expression signatures of stem cell quiescence, reduced oxidative metabolism, and improved patient outcomes. Consistent with these findings, we show that elevated FOXO3 activity significantly reduces the proliferation of GBM‐derived GSCs. Using RNA‐seq, we find that functional ablation of FOXO3 in GSCs rewires the transcriptional circuitry associated with metabolism, epigenetic stability, quiescence, and differentiation. Since FOXO3 has been implicated in healthy aging, we then investigated the extent to which it regulates common transcriptional programs in aging neural stem cells (NSCs) and GSCs. We uncover a shared transcriptional program and, most strikingly, find that FOXO3‐regulated pathways are associated with altered mitochondrial functions in both aging and GBM.

Conclusions

This work identifies a FOXO‐associated transcriptional program that correlates between GSCs and aging NSCs and is enriched for metabolic and stemness pathways connected with GBM and aging.
In Situ Electronic Redistribution Tuning of NiCo2S4 Nanosheets for Enhanced Electrocatalysis
Authors: Su Hui , Song Shaojia , Gao Yangqin , Li Ning , Fu Yang , Ge Lei , Song Weiyu , Liu Jian , Ma Tianyi
Published: December 2021

Metal Ru and vacancy engineering play an important role in oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). However, there are few reports targeted on electrocatalysts by simultaneously employing these two strategies. Herein, theoretical calculation firstly predicts that Ru and VS can regulate the adsorption energy of OER/HER intermediates for NiCo2S4 electrocatalysts. Then, a facile solvothermal‐photochemical strategy is utilized to synthesis series NiCo2S4 samples: through filling the solvothermal‐created VS in NiCo2S4–x with Ru single atoms (Ru‐NiCo2S4–x) under ultraviolet irradiation as OER catalysts. Besides, Ru nanoclusters are introduced into NiCo2S4 without VS (Ru‐NiCo2S4) for HER. As a result, the OER exchange current density of NiCo2S4–x is prominently boosted after decoration of Ru single atom, which possesses an eminently low overpotential of 190 mV@50 mA cm−2, while Ru‐NiCo2S4 shows superior HER performance (32 mV@10 mA cm−2) compared with Ru‐NiCo2S4–x, surpassing most reported electrocatalytic materials. Moreover, Ru‐NiCo2S4–x//Ru‐NiCo2S4 exhibits remarkable stability and catalytic performance in the overall water splitting, with a cell voltage value of 1.46 V at 10 mA cm−2 in 1.0 m KOH. Bader charge analysis unravels the “restricted‐delocalized‐restricted” phenomenon between electrons promote the electron interactions, which in turn improves electrochemical performance.
Freestanding Magnetic Microtissues for Tissue Engineering Applications
Authors: Santos Lúcia F. , Patrício Sónia G. , Silva Ana Sofia , Mano João F.
Published: December 2021

A long‐sought goal in tissue engineering (TE) is the development of tissues able to recapitulate the complex architecture of the native counterpart. Microtissues, by resembling the functional units of living structures, can be used to recreate tissues’ architecture. Howbeit, microfabrication methodologies fail to reproduce cell‐based tissues with uniform shape. At the macroscale, complex tissues are already produced by magnetic‐TE using solely magnetized cells as building materials. The enhanced extracellular matrix (ECM) deposition guaranties the conservation of tissues’ architecture, leading to a successful cellular engraftment. Following the same rational, now the combination of a versatile microfabrication‐platform is proposed with magnetic‐TE to generate robust micro‐tissues with complex architecture for TE purposes. Small tissue units with circle, square, and fiber‐like shapes are designed with high fidelity acting as building blocks for engineering complex tissues. Notably, freestanding microtissues maintain their geometry after 7 days post‐culturing, overcoming the challenges of microtissues fabrication. Lastly, the ability of microtissues in invading distinct tissue models while releasing trophic factors is substantiated in methacryloyl laminarin (LAM) and platelet lysates (PLMA) hydrogels. By simply using cells as building units and such microfabrication‐platform, the fabrication of complex multiscale and multifunctional tissues with clinical relevance is envisaged, including for therapies or disease models.
Designing Angstrom‐Scale Asymmetric MOF‐on‐MOF Cavities for High Monovalent Ion Selectivity
Authors: Abdollahzadeh Mojtaba , Chai Milton , Hosseini Ehsan , Zakertabrizi Mohammad , Mohammad Munirah , Ahmadi Hadi , Hou Jingwei , Lim Sean , Habibnejad Korayem Asghar , Chen Vicki , Asadnia Mohsen , Razmjou Amir
Published: December 2021

Biological ion channels feature angstrom‐scale asymmetrical cavity structures, which are the key to achieving highly efficient separation and sensing of alkali metal ions from aqueous resources. The clean energy future and lithium‐based energy storage systems heavily rely on highly efficient ionic separations. However, artificial recreation of such a sophisticated biostructure has been technically challenging. Here, a highly tunable design concept is introduced to fabricate monovalent ion‐selective membranes with asymmetric sub‐nanometer pores in which energy barriers are implanted. The energy barriers act against ionic movements, which hold the target ion while facilitating the transport of competing ions. The membrane consists of bilayer metal‐organic frameworks (MOF‐on‐MOF), possessing a 6 to 3.4‐angstrom passable cavity structure. The ionic current measurements exhibit an unprecedented ionic current rectification ratio of above 100 with exceptionally high selectivity ratios of 84 and 80 for K+/Li+ and Na+/ Li+, respectively (1.14 Li+ mol m−2 h−1). Furthermore, using quantum mechanics/molecular mechanics, it is shown that the combined effect of spatial hindrance and nucleophilic entrapment to induce energy surge baffles is responsible for the membrane's ultrahigh selectivity and ion rectification. This work demonstrates a striking advance in developing monovalent ion‐selective channels and has implications in sensing, energy storage, and separation technologies.
An In Situ Self‐Assembly Dual Conductive Shell Nanofiber Strain Sensor with Superior Sensitivity and Antibacterial Property
Authors: Zhang Wang , Lin Liwei , Zhang Ligong , Choi Yejung , Cho Youngseul , Chen Tianyu , Gao Jiefeng , Yao Hang , Piao Yuanzhe
Published: December 2021

At the moment, flexible, stretchable, and wearable strain sensors have extensive application prospect in medical healthcare for their abilities to instantly and accurately monitor human health and body movements, particularly suitable for patients with joint injury and movement disorder, which have attracted more and more attention. Hence, a multifunctional conductive nanofiber composite (M‐CNC) strain sensor with reliable antibacterial property is put forward. The thermoplastic polyurethane (TPU) nanofiber is served as the substrate, decorated by acid‐modified carbon nanotubes (ACNTs) and in situ self‐assembled silver nanoflowers (AgNFs), entitling the M‐CNC with double‐shell conductive networks. The M‐CNC (TPU/ACNT/AgNF) has a stable conductivity, which is up to 7.5 × 105 S m−1. Further, the double‐shell conductive networks have greatly enhanced the sensing performance of the M‐CNC strain sensor, possessing a useful gauge factor of 55 352, during the strain of 42% to 100%. Additionally, the outer AgNF shell structure is stable even after the cyclic test for 1000 times under the strain of 50%. The AgNF also endows the M‐CNC with great antibacterial property, indicating brilliant growth inhibition effects on Gram‐negative Pseudomonas aeruginosa and Gram‐positive Staphylococcus aureus.
Grayscale Stereolithography of Gradient Hydrogel with Site‐Selective Shape Deformation
Authors: Jiang Pan , Zhang Yuxin , Mu Xiaoxiao , Liu Desheng , Liu Yanhua , Guo Rui , Ji Zhongying , Wang Xinzhong , Wang Xiaolong
Published: December 2021

Hydrogels can convert external stimuli into shape deformation and mechanical motion, leading to the potential applications in intelligent devices and soft robotics. However, it is difficult to control the site‐selective shape deformation in a single hydrogel system in comparison with the traditional bilayer actuators with difference in structure or composition across the thickness. Here, a strategy to achieve the programmable shape deformation of hydrogel from a single precursor by grayscale stereolithography is proposed. The designed grayscale patterns can govern the spatially gradient crosslinking density of hydrogels, which leads to the heterogeneity in physicochemical performance, especially swelling ability. As a result, the swelling mismatch inducing the nonuniform internal stresses can drive the printed hydrogels to deform as the expected shape in three dimensions although there is no apparent asymmetric features and bilayer configuration. Grayscale light intensity and exposure time, as the digital printing codes can parametrically regulate the predictable shape deformation. More importantly, hydration and dehydration characterizations can endow the reversible feature of shape deformation hydrogel, benefiting to design the hydrogel actuators and sensitive devices. It is believed that integration of the advanced grayscale stereolithography together with the functional hydrogels uncovers a facile strategy to broad opportunities for sensors, soft robots, actuators, and so on.
Critical Role of High‐Lying Triplet States for Efficient Excitons Utilization in High‐Performance Non‐Doped Deep‐Blue Fluorescent and Hybrid White Organic Light‐Emitting Diodes
Authors: Li Baoxi , Li Ganggang , Zhang Han , Wu Haozhong , Chen Kongqi , Wang Zhiming , Tang Ben Zhong
Published: December 2021

For organic light‐emitting diodes (OLEDs), the characteristics of high‐lying excited states of pure organic materials significantly affect the utilization of triplet excitons, which are critical in the process of electroluminescence. Herein, two novel molecules, PT‐1 and PT‐2, with deep‐blue emission are obtained, which exhibit nearly identical photophysical behavior in the photoluminescence process. However, the remarkable distinction in the characteristics of the high‐lying triplet excited states between PT‐1 and PT‐2 leads to a significant difference in the electroluminescence performance. Moreover, the non‐doped OLED based on PT‐1 exhibits maximum external quantum efficiency (ηext) of 6.63% with a low efficiency roll‐off. In addition, the authors employ PT‐1 as the phosphorescent host materials to fabricate two‐color hybrid white OLEDs (WOLEDs), from which they can realize the transformation from warm‐white to quasi‐white light by tuning the thickness of emission layer, with maximum ηext and power efficiency (ηp) of 23.93%/84.37 lm W−1 and 10.49%/33.96 lm W−1, respectively. These results deeply demonstrate the effects of high‐lying excited states on electroluminescence and facilitate the preparation of functional OLEDs.
A Discrete Platinum(II) Metallacycle Harvesting Triplet Excitons for Solution‐Processed Deep‐Red Organic Light‐Emitting Diodes
Authors: Xing Hao , Yu Ying , Liu Junkai , Qin Peng , Lam Jacky Wing Yip , Shi Bingbing , Xie Guohua , Tang Ben Zhong
Published: December 2021

Platinum(II) coordination‐driven architectures have exhibited unique features in fabricating functional supramolecular materials. By introducing luminescent moieties into the ligand structure, various light‐emitting metallacycles and metallacages have been facilely prepared, presenting specific applications in chemical sensing, light‐harvesting, and bio‐imaging. Except for building up the metal–ligand bonds, the platinum(II) center should also benefit the ultimate luminescence due to its unique photophysical traits. Here, a platinum(II) metallacycle with deep‐red emission for solution‐processed organic light‐emitting diodes is reported. This metallacycle is assembled by mixing a 180° di‐Pt(II) acceptor with a pyridyl‐decorated ligand functionalized by a deep‐red fluorescent emitter. Notably, the platinum(II) acceptor permits the efficient intramolecular transfer of all electrically generated singlet and triplet excitons from itself to the fluorescent moiety, which dramatically enhances the external quantum efficiency of the device compared with the one consisting of the sole ligand. The present results reveal the function of platinum(II) metallacycles in light‐emitting devices, a finding which should apply to other coordination‐driven architectures with versatile properties.
Alleviation of π–π* Transition Enabling Enhanced Luminescence in Emerging TpyInClx (x = 3, 5) Perovskite Single Crystals
Authors: Zhang Yangyi , Yuan Songyang , Yuan Yaxuan , Bao Yunkai , Ran Qing , Liu Enming , Fan Jiandong , Li Wenzhe
Published: December 2021

Organic–inorganic hybrid metal halide perovskites have played an important role in optoelectronic and photonic community owing to their remarkably high photoluminescence quantum yields and color tunability with ultrafast emission performance. Herein, two kinds of novel perovskite single crystals, i.e., TpyInCl3 and TpyInCl5, grown by means of a solution‐processed hydrothermal method are innovatively designed. Regulating the polarity of the precursor solution allows to fine‐tune the light emission from pink to blue with an extremely short photoluminescence lifetime of 2.5 ns. The density functional theory calculations reveal that the unique luminescence characteristics are associated with the contribution of the terpyridine π–π* transition and the exciton quenching in the inorganic framework, that is, InCl3/[In2Cl10]4−, wherein the reduction of the recombination path and the increase of exciton quenching can effectively increase the luminous intensity. The current study provides a new paradigm toward designing multifunctional perovskite materials with tunable structure and electron dimension in emitter devices.
Synthesis of Two New Dinuclear Lanthanide Clusters and Visual Bifunctional Sensing Devices Based on the Eu Cluster
Authors: Jiang Yefei , Zheng Kai , Liu Ziqi , Yu Xiaobo , Yang Qingrong , Tang Ting , Zeng Chenghui
Published: December 2021

The development of visual and multifunctional sensors, and further the fabrication of portable sensing devices is of great importance. Herein, two dinuclear lanthanide clusters are designed, and their accurate molecules are determined to be [Ln2(DFBA)6(dmp)2(H2O)2] (Ln3+ = Eu3+ (1‐Eu) or Tb3+ (1‐Tb), HDFBA = 3,4‐difluorobenzoic acid, dmp = 4,7‐dimethyl‐1,10‐phenanthroline), by single‐crystal X‐ray diffraction. Interestingly, 1‐Eu shows rapid detection of ferrous ions (Fe2+) and acetylacetone (acac), with the limit of detection (LOD) as low as 5.6 and 1.0 ppb, respectively. LOD of 5.6 ppb for Fe2+ is far lower than the standard of World Health Organization (0.3 ppm, SDWA) and Chinese rural water quality standards (0.5 ppm, GB25467‐2010) for drinking water. As far as it is known, 1‐Eu is the most sensitive chemosensor for the detection of acac; the sensing can be discriminated by the naked eyes under 365 nm UV light. Furthermore, portable sensing devices of agarose gel, test paper, and sprayed films on plastic tube, glass, coin, test paper, stone, leaf, carbon rod, and iron sheet surfaces, based on 1‐Eu solution, are fabricated by facile methods, with visual and quick detection of Fe2+ in water under various conditions, and show excellent recyclable sensing performance for acac vapor.
Au/Si Bilayer Nanodisks with Tunable Localized Surface Plasmon Resonance for Optical Coherence Tomography in the Second Near‐Infrared Window
Authors: Lee Jinhyung , Lee Hyun-Ji , Lee Sang-Won , Na Hee-Kyung , Lee Tae Geol , Wi Jung-Sub , Kang Shinill
Published: December 2021

Bioimaging in the second near‐infrared (NIR‐II) window can help to obtain high‐resolution images and a high penetration depth. This study proposes an Au/Si bilayer plasmonic nanodisk (Au/Si ND) that has a resonance wavelength in the NIR‐II window caused by Si ND stacking on top of the Au ND with a resonance wavelength in the first near‐infrared window; the Si ND has a high refractive index. Au/Si NDs are physically synthesized using nanoimprint lithography and vacuum deposition. Optical coherence tomography (OCT) imaging is performed using synthesized Au/Si NDs as OCT contrast agents in the NIR‐II window. Due to the 2D circular shape and its remarkable response to random incident light, the Au/Si NDs exhibit approximately 250‐fold greater OCT signal intensity than do commercial 1D Au nanorods, as well as fourfold greater penetration depth and improved OCT image contrast.
Plasmonic Terahertz Nonlinearity in Graphene Disks
Authors: Han Jeong Woo , Chin Matthew L. , Matschy Sebastian , Poojali Jayaprakash , Seidl Angelika , Winnerl Stephan , Hafez Hassan A. , Turchinovich Dmitry , Kumar Gagan , Myers-Ward Rachael L. , Dejarld Matthew T. , Daniels Kevin M. , Drew Howard Dennis , Murphy Thomas E. , Mittendorff Martin
Published: December 2021

The discovery of graphene and its unique optical and electronic properties has triggered intense developments in a vast number of optoelectronic applications, especially in spectral regions that are not easily accessible with conventional semiconductors. Particularly in the THz regime, where the free‐carrier interaction with low‐energetic photons usually dominates, detectors and modulators based on graphene often feature an improved response time. Nevertheless, the light−matter interaction suffers from the small interaction volume. One way to enhance the efficiency of such devices at elevated frequencies is by patterning graphene into plasmonic structures like disks. In addition to the increased linear absorption, the plasmon resonance also creates a strong, surface‐localized field that enhances the nonlinear optical response. While experimental studies so far have focused on hot carrier effects, theoretical studies also suggest an increase in the nonlinearity beyond thermal effects. Herein, polarization‐dependent pump‐probe measurements on graphene disks that disentangle the contributions of thermal and plasmonic nonlinearity are presented. An increase in the pump‐induced transmission is observed when pump and probe radiation are copolarized. To further elucidate the interplay of thermal and plasmonic effects, a model that supports the origin of the polarization‐dependent enhancement of the observed THz nonlinearities is developed.
Antiferromagnetic Ordering and Uncoupled Spins in CaFe2O4 Thin Films Probed by Spin Hall Magnetoresistance
Authors: Damerio Silvia , Kaverzin Alexey A. , Ocelík Václav , Hoogeboom Geert R. , van Wees Bart J. , Noheda Beatriz
Published: December 2021

CaFe2O4 is a uniaxial antiferromagnet displaying two coexisting magnetic orderings, A and B, characterized by ↑↑↓↓ and ↑↓↑↓ spin modulation, respectively, and the emergence of a net magnetization in a limited temperature range, which is not yet understood. The spin Hall magnetoresistance (SMR) is probed at the interface between Pt and CaFe2O4 and the crystallographic domain structure of thin film samples is exploited to perform single‐ and multi‐domain scale measurements. The SMR response, upon rotating the magnetic field along three orthogonal planes, shows little effect of the strong magnetocrystalline and shape anisotropies. Together with the response to a varying magnetic field strength, the modulations in the SMR signal allow to extract two contributions: one corresponds to the long‐range antiferromagnetic ordering, supporting a single ground state scenario; while the second contribution originates from uncompensated, non‐interacting spins. These are expected to exist at the antiphase boundaries between antiferromagnetic domains. Here, it is shown that these are also uncoupled from the antiferromagnetic ordering. Nonetheless, the long range correlations that emerge in the proximity of the critical antiferromagnetic transition can give rise to ordering of the uncompensated spins and be responsible for the net magnetization observed in this antiferromagnet.
Rational Design and Synthesis of Nickel Niobium Oxide with High‐Rate Capability and Cycling Stability in a Wide Temperature Range
Authors: Lv Changpeng , Lin Chunfu , Zhao X. S.
Published: December 2021

Conductive nickel niobium oxide (Ni2Nb34O87) is rationally designed and synthesized as a safe anode material for lithium‐ion storage. Ni2Nb34O87 exhibits high‐rate capability and cycling stability in the temperature range between ‐10 and 60 °C. At 25 °C, it delivers reversible specific capacities of 339 mAh g‐1 at 0.1C with 98.1% capacity retention after 1000 cycles at 20C. At ‐10 °C, it displays a reversible capacity of 207 mAh g‐1 at 0.1C with 64.0% capacity retention when the C‐rate increases from 0.5C to 2C and no capacity decay after 1000 cycles at 2C. At 60 °C, it exhibits a reversible capacity of 224 mAh g‐1 at 0.1C with 65.3% capacity retention when the C‐rate increases from 0.5C to 10C and 78.7% capacity is maintained after 1000 cycles at 10C. In‐situ X‐ray diffraction measurements combined with Rietveld refinements reveal that the interlayer spacing of Ni2Nb34O87 with a shear ReO3‐type layered structure is relatively large, effectively facilitating lithium‐ion transport and storage with 6.71% unit‐cell‐volume expansion upon lithiation. This new anode material holds great promise for lithium‐ion batteries working in a wide temperature range.
A Stable, Low Permeable TEMPO Catholyte for Aqueous Total Organic Redox Flow Batteries
Authors: Hu Bo , Hu Maowei , Luo Jian , Liu T. Leo
Published: December 2021

Aqueous organic redox flow batteries (AORFBs) are highly attractive for large‐scale energy storage because of their nonflammability, low cost, and sustainability. (2,2,6,6‐Tetramethylpiperidin‐1‐yl)oxyl (TEMPO) derivatives, a class of redox active molecules bearing air‐stable free nitroxyl radicals and high redox potential (>0.8 V vs NHE), has been identified as promising catholytes for AORFBs. However, reported TEMPO based molecules are either permeable through ion exchange membranes or not chemically stable enough for long‐term energy storage. Herein, a new TEMPO derivative functionalized with a dual‐ammonium dicationic group, N1, N1, N1, N3, N3, 2, 2, 6, 6‐nonamethyl‐N3‐(piperidinyloxy)propane‐1,3‐bis(ammonium) dichloride (N2‐TEMPO) as a stable, low permeable catholyte for AORFBs is reported. Ultraviolet–visible (UV–vis) and proton nuclear magnetic resonance (1H‐NMR) spectroscopic studies reveal its exceptional stability and ultra‐low permeability (1.49 × 10−12 cm2 s−1). Coupled with 1,1′‐bis[3‐(trimethylammonio)propyl]‐4,4′‐bipyridinium tetrachloride ((NPr)2V) as an anolyte, a 1.35 V N2‐TEMPO/(NPr)2V AORFB with 0.5 m electrolytes (9.05 Wh L−1) delivers a high power density of 114 mW cm−2 and 100% capacity retention for 400 cycles at 60 mA cm−2. At 1.0 m electrolyte concentrations, the N2‐TEMPO/(NPr)2V AORFB achieves an energy density of 18.1 Wh L−1 and capacity retention of 90% for 400 cycles at 60 mA cm−2.
Structure and morphological changes of multilayer separators for lithium‐ion batteries under abuse/overcharge conditions
Authors: Yeh Wei‐Ting , Huang Yi‐Fang , Wu Cheng‐Chang , Hong Po‐Da
Published: December 2021

Most separators for lithium‐ion (Li‐ion) batteries are manufactured using polyolefins. However, such thermoplastic materials may undergo structural changes under high voltage or temperature. Thus, this study investigates the structural and morphological changes of separators during overcharge conditions. Unlike a single‐layer polypropylene (PP) separator, a composite separator with an interface, such as a PP/polyethylene (PE)/PP separator, exhibits a characteristic peak in voltage during the overcharging process before the occurrence of the shutdown mechanism by the PE layer. As the temperature rises, parts of the irregular crystalline structure of PE melt because of their lower melting temperature at the PP/PE interface. This results in local shrinkage and interfaces disturbance, and the Li‐ion channel becomes partially blocked. The Li‐ions follow alternative channels, and this causes the voltage to abruptly increase during overcharging. The experimental results clearly indicate that the microstructural changes of the separator are important in the above‐mentioned phenomenon.