bluuebunny/crossref_metadata_2025 huggingface dataset:
Nar Kabuğu Ekstresinin Sıçanlarda Diyabetik Şartlarda Sepsis ile İndüklenen Akciğer Hasarına Karşı Etkileri
Authors: UĞAN Rüstem Anıl , YAYLA Muhammed , ÜN Harun , CİVELEK Maide Sena , KILIÇLE Pınar Aksu
Published: September 2020

Amaç: Diabetes mellitus (DM), tam veya kısmi insülin yokluğuyla ortaya çıkan bir metabolik hastalıktır. Sepsis, konakçının enfeksiyona veya bir travmaya karşı göstermiş olduğu kompleks enflamatuvar yanıttır. Sepsisin klinik seyri diyabetli hastalarda normal bireylere nazaran daha ağır seyretmektedir. Nar kabuğu ekstresinin yüksek antioksidan kapasitesi, anti-kanser, antimikrobiyal, anti-enflamatuvar ve anti-diyabetik etkinliği vardır. Bu çalışmanın amacı, diyabetik şartlarda sepsis ile indüklenen akciğer hasarına karşı nar kabuğu ekstresinin anti-oksidan ve anti-sitokin özelliklerini araştırmaktır.

Yöntemler: Nar meyvesinin kabukları soyularak kurutuldu. Ekstraksiyon işlemleri uygulandı. Ekstraksiyon çözücüsü olarak etanol kullanıldı. Ekstraksiyon işlemlerinden sonra çözücü buharlaştırıldı ve nar kabuk ekstresi elde edildi. Bu Çalışmada, 30 adet sıçan kullanıldı. Gruplar; Grup 1: Kontrol, Grup 2: Sepsis, Grup 3: DM+S (Diyabet + Sepsis), Grup 4: DM+S+NKE250 (Diyabet + Sepsis + Nar kabuğu ekstresi 250 mg/kg), Grup 5: DM+S+NKE500 (Diyabet + Sepsis + Nar kabuğu ekstresi 500 mg/kg). Diyabet Tek doz 55 mg/kg streptozosin ile oluşturuldu. 72 saat sonra açlık kan şekerleri ölçüldü açlık kan şekerleri 250 mg/dl’den yüksek çıkan sıçanlar diyabet oldukları kabul edildi. Diyabet tespitinden sonra 10 gün boyunca nar kabuğu ekstresi 250 mg/kg ve 500 mg/kg dozlarında oral olarak uygulandı. 10. gün sonunda 5 mg/kg dozunda lipopolisakkarit intraperitoneal uygulandı. 12 saat sonra akciğer dokusu elde edildi. SOD aktivitesi, GSH ve MDA seviyeleri ile TNF-α ve IL-1β mRNA ekspresyonu seviyeleri akciğer dokusunda ölçüldü.

Bulgular: Kontrol grubuyla karşılaştırıldığında, sepsis grubunda, SOD aktivitesi ve GSH seviyesinin azaldığı görüldü. Diyabet+sepsis grubundaki SOD aktivitesi ve GSH seviyesinin hem kontrol hem de sepsis grubuna göre düştüğü bulundu. Sepsis grubunda TNF-α ve IL-1β mRNA ekspresyonu ile MDA seviyesinin Kontrol grubuna göre yükseldiği görüldü. Diyabet+sepsis grubundaki TNF-α ve IL-1β mRNA ekspresyonu ile MDA seviyesinin hem kontrol hem de sepsis grubuna göre arttığı bulundu. Diyabet+sepsis grubuyla karşılaştırıldığında, nar kabuğu ekstresi uygulanan gruplarda doza bağlı olarak SOD aktivitesinin, GSH seviyesinin arttığı ve TNF-α ve IL-1β mRNA ekspresyonu ve MDA seviyelerinin düştüğü görüldü.

Sonuç ve Yorum: Nar kabuğu ekstresi antioksidan ve oksidanlar arasındaki dengeyi düzenlemekte ve sitokin miktarını azaltmaktadır. Bu sebeplerle, antioksidan/oksidan dengesinin bozulduğu ve sitokin fırtınasının yoğun görüldüğü diyabet ve sepsis hastalıklarının birlikte olduğu durumlarda nar kabuğu ekstresinin kullanımı akciğer hasarında faydalı sonuçlar verecektir.
Sağlık Çalışanlarının Kızamık, Kızamıkçık, Kabakulak ve Suçiçeği Geçirme ve Aşılanma Durumlarının Değerlendirilmesi (Ülke Geneli Çok Merkezli Çalışma)
Authors: ALAY Handan , OĞUZÖNCÜL Ayşe Ferdane , TORUN Ayşe
Published: September 2020

Giriş: Kızamık, kızamıkçık, kabakulak (KKK) ve suçiçeği hastalıkları aşı ile önlenebilir hastalıklar arasında yer almaktadır. Sağlık çalışanlarının enfeksiyon hastalıklarına karşı bağışıklık ve aşılanma durumlarının bilinmesi, duyarlı personelin belirlenmesi ve ardından uygun aşılama programlarının geliştirilmesi enfeksiyonların önlenmesi ve kontrolü için önemlidir.
Amaç: Ülke genelini kapsayan çok merkezli olarak gerçekleştirilen bu çalışmada, KKK ve suçiçeği gibi döküntülü hastalıklarla karşılaşma riski fazla olan sağlık çalışanlarının hastalık geçirme, test yaptırma ve aşılanma durumlarının belirlenmesi amaçlanmıştır.
Yöntemler: Sağlık çalışanlarının demografik özelliklerini, KKK ve suçiçeği hastalığını geçirme ve aşılanma durumlarını öğrenmeye yönelik bir anket formu oluşturulmuş ve bu form web sayfası üzerinden online ulaşılabilen bir link aracılığıyla sağlık çalışanlarına iletilerek katılımcıların anketteki soruları yanıtlamaları istenmiştir.
Bulgular: Çalışmaya Türkiye’de toplam yedi bölgeden 12.475 sağlık çalışanı katıldı. Katılımcıların 8099 (%64,9)’u kadın, 4376 (%35,1)’i erkek ve yaş ortalaması 35.4±9.4 yıl idi. KKK ve suçiçeği geçirmeme durumları %22,4-34,9 arasında idi. Sağlık çalışanlarının KKK ve suçiçeği aşılanma durumları sorgulandı. KKK için katılımcıların %22,3’ü (n=2784), suçiçeği aşısı için katılımcıların %22’si (n=2748) bu soruya cevap vermedi. KKK ve suçiçeği aşısı yaptıranlar sırasıyla 2048 (%21,1) ve 4451 (%45,8) idi. KKK ve suçiçeği serolojisi baktırmayan sağlık çalışanlarının sayısı sırasıyla 8953 (%79), 9010 (%80,1), 9363 (%83,5) ve 9591 (%85,4) idi. Kızamık IgG serolojisi baktıran 2383 kişiden %77,6’sı kızamık IgG pozitif, 2233 kişinin %81,5’i kızamıkçık IgG pozitif, 1854 kişinin %81.6’sı kabakulak IgG pozitif ve 1644 kişinin %83,6’sı suçiçeği IgG sonucu pozitifdi. Katılımcıların cinsiyet, yaş ve meslek gruplarına göre KKK ve suçiçeği aşısı yaptırma durumları değerlendirildiğinde istatiksel anlamlılık yoktu (p>0.05).
Sonuç: Çalışmamızda serolojik sonuçlarına baktırmayan sağlık çalışanlarının oranının fazla olması ülke genelinde bu konudaki eksiklikleri ön plana çıkarmaktadır. Sağlık çalışanlarının serolojik değerlendirmeleri işe başlamadan önce kontrol edilmeli ve gerekli aşı programına alınmalıdır.
Badie avant Badie. L’apport de la sociologie historique comparative à sa perspective des relations internationales
Authors: Paquin Stéphane
Published: September 2020

Il y a deux Badie : le spécialiste de la sociologie de l’État et de la sociologie historique comparative, et le spécialiste de la sociologie des relations internationales. L’objectif de cet article est d’exposer les éléments de continuité entre les deux. En effet, lorsque Bertrand Badie entreprend au début des années 1990 son virage internationaliste, les leçons qu’il a tirées de ses analyses en sociologie politique comparée sur l’État, le rapport à l’histoire et le rôle de la culture demeurent centraux dans son analyse. Le résultat de cette importation d’un champ disciplinaire dans un autre représente une des contributions majeures de Badie à l’étude de la sociologie des relations internationales. Ces apports expliquent pourquoi la perspective badienne des relations internationales s’écarte sensiblement des perspectives dominantes de l’époque.
Sociedad de consumos
Authors: Sivera Sílvia
Published: September 2020

En 1899 Thorstein Veblen escribió La teoría de la clase ociosa como una crítica a una sociedad norteamericana que en dos décadas se convertiría en la llamada sociedad de consumo. Durante aquellos felices veinte (roaring twenties) se infló lo que sería una de las burbujas económicas más sangrantes y, un siglo más tarde, tras los meses en los que nos hemos visto en la obligación de permanecer en burbujas físicas por el confinamiento, hablar de consumo en singular puede revelarse insuficiente.
Phosphatidylinositol 3-phosphate and Hsp70 protect Plasmodium falciparum from heat-induced cell death
Authors: Lu Kuan-Yi , Pasaje Charisse Flerida A , Srivastava Tamanna , Loiselle David R , Niles Jacquin C , Derbyshire Emily
Published: September 2020

Phosphatidylinositol 3-phosphate (PI(3)P) levels in Plasmodium falciparum correlate with tolerance to cellular stresses caused by artemisinin and environmental factors. However, PI(3)P function during the Plasmodium stress response was unknown. Here, we used PI3K inhibitors and antimalarial agents to examine the importance of PI(3)P under thermal conditions recapitulating malarial fever. Live cell microscopy using chemical and genetic reporters revealed that PI(3)P stabilizes the digestive vacuole (DV) under heat stress. We demonstrate that heat-induced DV destabilization in PI(3)P-deficient P. falciparum precedes cell death and is reversible after withdrawal of the stress condition and the PI3K inhibitor. A chemoproteomic approach identified PfHsp70-1 as a PI(3)P-binding protein. An Hsp70 inhibitor and knockdown of PfHsp70-1 phenocopy PI(3)P-deficient parasites under heat shock. Furthermore, PfHsp70-1 downregulation hypersensitizes parasites to heat shock and PI3K inhibitors. Our findings underscore a mechanistic link between PI(3)P and PfHsp70-1 and present a novel PI(3)P function in DV stabilization during heat stress.
A multi-layered and dynamic apical extracellular matrix shapes the vulva lumen in Caenorhabditis elegans
Authors: Cohen Jennifer D , Sparacio Alessandro P , Belfi Alexandra C , Forman-Rubinsky Rachel , Hall David H , Maul-Newby Hannah , Frand Alison R , Sundaram Meera V
Published: September 2020

Biological tubes must develop and maintain their proper diameter to transport materials efficiently. These tubes are molded and protected in part by apical extracellular matrices (aECMs) that line their lumens. Despite their importance, aECMs are difficult to image in vivo and therefore poorly understood. TheCaenorhabditis elegansvulva has been a paradigm for understanding many aspects of organogenesis. Here we describe the vulva luminal matrix, which contains chondroitin proteoglycans, Zona Pellucida (ZP) domain proteins, and other glycoproteins and lipid transporters related to those in mammals. Confocal and transmission electron microscopy revealed, with unprecedented detail, a complex and dynamic aECM. Different matrix factors assemble on the apical surfaces of each vulva cell type, with clear distinctions seen between Ras-dependent (1°) and Notch-dependent (2°) cell types. Genetic perturbations suggest that chondroitin and other aECM factors together generate a structured scaffold that both expands and constricts lumen shape.
Molecular basis for substrate specificity of the Phactr1/PP1 phosphatase holoenzyme
Authors: Fedoryshchak Roman O , Přechová Magdalena , Butler Abbey M , Lee Rebecca , O'Reilly Nicola , Flynn Helen R , Snijders Ambrosius P , Eder Noreen , Ultanir Sila , Mouilleron Stephane , Treisman Richard
Published: September 2020

PPP-family phosphatases such as PP1 have little intrinsic specificity. Cofactors can target PP1 to substrates or subcellular locations, but it remains unclear how they might confer sequence-specificity on PP1. The cytoskeletal regulator Phactr1 is a neuronally enriched PP1 cofactor that is controlled by G-actin. Structural analysis showed that Phactr1 binding remodels PP1's hydrophobic groove, creating a new composite surface adjacent to the catalytic site. Using phosphoproteomics, we identified mouse fibroblast and neuronal Phactr1/PP1 substrates, which include cytoskeletal components and regulators. We determined high-resolution structures of Phactr1/PP1 bound to the dephosphorylated forms of its substrates IRSp53 and spectrin αII. Inversion of the phosphate in these holoenzyme-product complexes supports the proposed PPP-family catalytic mechanism. Substrate sequences C-terminal to the dephosphorylation site make intimate contacts with the composite Phactr1/PP1 surface, which are required for efficient dephosphorylation. Sequence specificity explains why Phactr1/PP1 exhibits orders-of-magnitude enhanced reactivity towards its substrates, compared to apo-PP1 or other PP1 holoenzymes.
Symbiont-mediated cytoplasmic incompatibility: What have we learned in 50 years?
Authors: Shropshire J Dylan , Leigh Brittany , Bordenstein Seth R
Published: September 2020

Cytoplasmic incompatibility (CI) is the most common symbiont-induced reproductive manipulation. Specifically, symbiont-induced sperm modifications cause catastrophic mitotic defects in the fertilized embryo and ensuing lethality in crosses between symbiotic males and either aposymbiotic females or females harboring a different symbiont strain. However, if the female carries the same symbiont strain, then embryos develop properly, thereby imparting a relative fitness benefit to symbiont-transmitting mothers. Thus, CI drives maternally-transmitted bacteria to high frequencies in arthropods worldwide. In the past two decades, CI experienced a boom in interest due to its (i) deployment in worldwide efforts to curb mosquito-borne diseases, (ii) causation by bacteriophage genes,cifAandcifB, that modify sexual reproduction, and (iii) important impacts on arthropod speciation. This review serves as a gateway to experimental, conceptual, and quantitative themes of CI and outlines significant gaps in understanding CI’s mechanism that are ripe for investigation from diverse subdisciplines in the life sciences.
The mechanism and detection of alternative splicing events in circular RNAs
Authors: Li Xiaohan , Zhang Bing , Li Fuyu , Yu Kequan , Bai Yunfei
Published: September 2020

Circular RNAs (circRNAs) are considered as functional biomolecules with tissue/development-specific expression patterns. Generally, a single gene may generate multiple circRNA variants by alternative splicing, which contain different combinations of exons and/or introns. Due to the low abundance of circRNAs as well as overlapped with their linear counterparts, circRNA enrichment protocol is needed prior to sequencing. Compared with numerous algorithms, which use back-splicing reads for detection and functional characterization of circRNAs, original bioinformatic analyzing tools have been developed to large-scale determination of full-length circRNAs and accurate quantification. This review provides insights into the complexity of circRNA biogenesis and surveys the recent progresses in the experimental and bioinformatic methodologies that focus on accurately full-length circRNAs identification.
Infidel or Paganus?
Authors: Cole Juan
Published: September 2020

This article explores the meaning of the root k-f-r in the Quran, questioning the practice of translating the noun kāfir as “infidel.” It argues for a distinction between the idiomatic phrasal verb kafara bi-, which does mean to reject or disbelieve, and the simple intransitive verb kafara and its deverbal nouns, which are used in the Quran in a large number of different ways. This polysemy is explored through contextual readings of Quran passages. It is argued that the noun kāfir, unlike the verb kafara, is used only with regard to adherents of traditional polytheism and is not deployed in an unmodified way with regard to Jews and Christians. The possible influence on the Arabic kafara of Greek and Latin conceptions is also broached.
Indic-Vernacular Bitexts from Thailand
Authors: Walker Trent
Published: September 2020

In the late first and early second millennia, mainland Southeast Asians created sophisticated techniques to accurately and efficiently render Pali into local vernaculars, including Burmese, Khmer, Khün, Lanna, Lao, Lü, Mon, and Siamese. These techniques for vernacular reading, parallel to approaches for reading Latin in medieval Europe and Literary Sinitic in Japan, Korea, and Vietnam, led to the development of bitexts that contained a mix of Pali and vernacular material.

Such bitexts, arranged in both interlinear and interphrasal formats, gradually allowed second-millennium Southeast Asian writers to sprout a vernacular literature from the established branches of Pali genres. Bitexts themselves formed the basis for a new literary style that stemmed from the techniques of vernacular reading, a style that set the standard for belles-lettres until the early twentieth century. The spread of Pali-vernacular bitexts in Southeast Asia allowed for the literary elevation of the vernacular without renouncing the cosmopolitan idiom of Pali.

To support these arguments, this article draws on some of the earliest examples of bitexts in Central Thailand (Siam) and Northern Thailand (Lanna). These include a hitherto undeciphered form of manuscript annotation in seventeenth- to nineteenth-century Siam; two of the oldest palm-leaf documents surviving in any Tai language, from sixteenth-century Lanna; and the oldest known Pali-Siamese literary work, thought to be composed in 1482. These bitexts provide detailed evidence for vernacular reading and the emergence of vernacular literature in mainland Southeast Asian in general and Thailand in particular.
Kenya Education Management Institute’s Capacity Building Programme and Public Primary School Head Teachers’ Competencies in Teacher Supervision in Uasin Gishu County, Kenya
Authors: Ongori Josephine G. , Kitainge Kisilu , Kipkoech Lydia
Published: September 2020

Aims: Education is the foundation and pillar of life. The study assessed the influence of Kenya Education Management Institute (KEMI’s) capacity building programme on head teachers' competencies in teacher supervision in public primary schools in Uasin Gishu County, Kenya.

Study Design: The study adopted a descriptive survey research design.

Place and Duration of Study: This study was conducted in Uasin Gishu County of North Rift region between January and March 2018.

Methodology: It targeted six Sub-County Education Officers and 471 head teachers in public primary schools in the County. Simple random sampling was used to select 30% (141) of the public primary schools proportionately from each of the six sub-counties in the County. All the head teachers of the public primary schools selected participated in the study. Data was also collected from all the six Sub-County Directors of Education of Moiben, Wareng, Turbo, Kapseret, Ainabkoi and Soy. Data was collected using interviews and questionnaire. Data analysis using descriptive statistics was computed with frequencies, percentages, means, medians and standard deviations. The findings were then presented using, tables, charts and graphs.

Results: Out of the 132 Head teachers, the research results indicated that there was a strong positive correlation between KEMI’s capacity building programme and head teachers’ competencies in teacher supervision, r (132) = 0.555, P = .05. KEMI should use the information from this study to organize teacher training programmes to improve their schools and put in place strategies to help enhance management practices in schools and ultimately the student academic achievement. The findings of the study may be importance to Kenya Education Management Institute (KEMI) in tailoring their training needs of head teachers to enhance professional development and leadership in schools.

Conclusion: Based on the findings of the study, it can be concluded that KEMI capacity building program had enhanced head teachers’ competence in monitoring teacher’s performance in class and outside class, and helped them in cultivating good relationship with the teachers and building motivating climate to enhance teamwork among teachers. Further, the findings also indicates that KEMI capacity building program had helped them in appraising teacher’s performance objectively and helped them in providing teacher’s opportunity for professional growth, proper delegation of duties and it had enhanced the recommendation of teachers for upward mobility.
Synergistic Impact of Co-applied Micronized Sulfur and Nitrogen on Agronomical Traits of a Modern Spring Wheat Cultivars Grown in Alkaline Soil
Authors: Morsy Sabah
Published: September 2020

Wheat (Triticum aestivum L.) uptakes only 40 to 60% of the soil available nitrogen. Sulfur deficiencies depress both nitrate uptake and nitrate reductase activity resulting in low nitrogen use efficiency. Soil and foliar supplied sulfur in combinations with foliar nitrogen were used on three of the modern and commercially grown wheat cultivars. The experiment was conducted in two consecutive growing seasons; 2017 and 2018 in a high pH soil, 8.55. Our results indicated that 714 kg ha-1 of pre-planting sulfur (SS) and spraying twice with 6.66% urea and 2.2% micronized sulfur (S1FS1N1) during stages 13 & 41 on Zadok`s scale, increased grain yield, total protein content, straw yield and plant height by 31.58, 26.09, 18.37 and 7.9% respectively. The results indicated a significant and positive impact sulfur-nitrogen combinations when applied on top of pre-planting applied sulfur. However, foliar sprayed sulfur had a more substantial effect on all traits, compared to the pre-planting sulfur or the foliar sprayed N, suggesting interference effect of the alkaline soil with the amount of sulfur recovered from the soil. When N and S foliar were applied simultaneously, a more substantial increase in grain yield, plant height, straw yield and total protein content was observed, suggesting a synergistic effect between these two elements. We attributed the positive effect of S1FS1N1 on improving photosynthates translocation from the sources to sinks. In addition to improving nitrogen use efficiency while reducing the plant content of NO−3 by optimizing the S/N ratio and reducing sulfur deficiency. Based on our results, we concluded that the foliar application of micronized S has the potential to improve the overall performance of wheat plants. Thus, we recommend enriching nitrogen and phosphate fertilizers with sulfur for alkaline soils.
The Production of Biodiesel from Sewage Sludge Via Soxlet Extraction Using Hexane and Ethyl Acetate in Ratio 2:1 As the Organic Solvent and Transesterification Reaction
Authors: Ivwurie W. , Okoro B.
Published: September 2020

The Lipid/oil was extracted from reduced dried primary sewage sludge particle using soxhlet extraction method with Hexane and Ethyl Acetate in the ratio 2:1 as the extracting solvent. The extracted oil gave 15.03% percentage yield with density of 0.845 g/ml, pH value of 8.97, specific gravity of 0.845, viscosity of 41.20 mm2/sec, kinematic viscosity of 42.18 mm2/sec. The lipid/oil was brownish black in colour with a pungent smell. The chemical analyses revealed saponification value of 168.00 mgKOH/g, acid value of 5.60 mgKOH/g and free fatty acid value of 2.80%.

The physicochemical analyses of the biodiesel produced gave a c percentage yield of 40% biodiesel, density of 0.845 Kg/ml, pH value of 8.50, specific gravity of 0.845, kinematic viscosity of 4.80 mm2/s, acid value of 0.37 mg KOH/g, and flash point of 150°C, cloud point of 5°C and pour point of -2°C. The results of the physicochemical parameters from the research shows that the feedstock (primary sewage sludge) would be a good source for the production of biodiesel.
Timing of Childhood‐Onset Systemic Lupus Erythematosus Diagnosis Relative to Menarche and the Impact on Final Adult Height
Authors: Sontichai Watchareewan , Liao Fangming , Dominguez Daniela , Levy Deborah M. , Al Mutairi Muna , Ng Lawrence , Silverio Frank , Silverman Earl D. , Wasserman Jonathan D. , Hiraki Linda T.
Published: September 2020

Objective

The aim of this study was to examine the impact of timing of a childhood‐onset systemic lupus erythematosus (SLE) diagnosis relative to menarchal status, on final height, accounting for disease‐associated factors.

Methods

We conducted a cohort study of female patients age <18 years at childhood‐onset SLE diagnosis, followed at a tertiary care pediatric center from July 1982 to March 2016 and restricted to patients with documented age of menarche and final height. We compared final height between patients diagnosed pre‐ and postmenarche. We tested the association of the timing of childhood‐onset SLE diagnosis with final height, adjusted for ethnicity, in linear regression models. We performed subgroup analyses of patients with growth during follow‐up, additionally adjusting for average daily corticosteroid dose and disease activity.

Results

Of 401 female childhood‐onset SLE patients in the study, 115 patients (29%) were diagnosed premenarche and 286 (71%) postmenarche. Patients diagnosed premenarche were older at menarche compared with patients diagnosed postmenarche (mean ± SD age 13.5 ± 1.4 versus 12.5 ± 1.3 years; P < 0.001). The mean ± SD final height for girls diagnosed postmenarche (161.4 ± 6.9 cm) was greater than for those diagnosed premenarche (158.8 ± 7.3 cm; P = 0.001). In regression analysis, those diagnosed postmenarche were significantly taller than those diagnosed premenarche, as adjusted for ethnicity and disease severity (mean ± SD β = 2.6 ± 0.7 cm; P = 0.0006).

Conclusion

In this large cohort study of girls with childhood‐onset SLE, patients diagnosed postmenarche achieved a taller final height than those diagnosed premenarche, even after accounting for ethnicity and disease severity.
A Stretchable Highoutput Triboelectric Nanogenerator Improved by MXene Liquid Electrode with High Electronegativity
Authors: Cao Wen‐Tao , Ouyang Han , Xin Wei , Chao Shengyu , Ma Chang , Li Zhou , Chen Feng , Ma Ming‐Guo
Published: September 2020

Growing demand in intelligent wearable electronics raises an urgent requirement to develop deformable and durable power sources with high electrical performance. Here, a stretchable and shape‐adaptive triboelectric nanogenerator (TENG) based on a MXene liquid electrode is proposed. The open‐circuit voltage of an MXene‐based TENG reaches up to 300 V. The excellent fluidity and highly electronegativity of the MXene liquid electrode, gives the TENG long‐term reliability and stable electrical output regardless of diverse extreme deformations. With harvesting mechanical energy from hand tapping motion, the TENG in a self‐charging system can charge up capacitors to drive wearable electronics. Moreover, the TENG can be attached to both human skin and clothes as a human motion monitoring sensor, which can inspect the frequency and amplitude of various physiological movements. This work provides a new methodology for the construction of stretchable power sources and self‐powered sensors, which have potential applications in diverse fields such as robotics, kinesiology, and biomechanics.
4D Printing Auxetic Metamaterials with Tunable, Programmable, and Reconfigurable Mechanical Properties
Authors: Xin Xiaozhou , Liu Liwu , Liu Yanju , Leng Jinsong
Published: September 2020

Auxetic mechanical metamaterials, which expand transversally when axially stretched, are widely used in flexible electronics and aerospace. However, these chiral metamaterials suffer from three severe limitations as a typical auxetic metamaterials: narrow strain range, non‐tunable mechanical behaviors, and fixed properties after fabrication. In this work, 4D printing chiral metamaterials with tunable, programmable, and reconfigurable properties are developed. The deformation mode transforms from bending dominated to stretching dominated under large deformation, leading to the stress–deformation (σ–λ) behavior of the auxetic metamaterials similar to those of the biomaterials (“J”‐shaped), such as tissues or organs. The programmability and reconfigurability of the developed chiral metamaterials allow mechanical behavior to change between different biomaterials with high precision. Furthermore, scaffolds with personalized mechanical properties as well as configurations and metamaterials‐based light‐emitting diode integrated devices demonstrate potential applications in tissue engineering and programmable flexible electronics.
Heat Transport without Heating?—An Ultrafast X‐Ray Perspective into a Metal Heterostructure
Authors: Pudell Jan‐Etienne , Mattern Maximilian , Hehn Michel , Malinowski Grégory , Herzog Marc , Bargheer Matias
Published: September 2020

When the spatial dimensions of metallic heterostructures shrink below the mean free path of its conduction electrons, the transport of electrons and hence the transport of thermal energy by electrons continuously changes from diffusive to ballistic. Electron–phonon coupling sets the mean free path to the nanoscale and the time for equilibration of electron and lattice temperatures to the picosecond range. A particularly intriguing situation occurs in trilayer heterostructures combining metals with very different electron–phonon coupling strength: Heat energy deposited in few atomic layers of Pt is transported into a nanometric Ni film, which is heated more than the Cu film through which the heat is released. Femtosecond pump‐probe experiments with hard X‐ray pulses provide a layer‐specific probe of the heat energy. A purely diffusive two‐temperature model with increased thermal conductivity of hot electrons excellently reproduces the observed signals from all three layers. At the time when the Ni lattice is maximally heated, no significant heat has entered the Cu lattice. This phenomenon would be enhanced in thinner layers where ballistic transport dominates. In this context it is shown that purely diffusive transport can lead to a linear time‐to‐length dependence that must not be misinterpreted as ballistic transport.
Frequency‐Coded Passive Multifunctional Elastic Metasurfaces
Authors: Rong Junjie , Ye Wenjing , Zhang Shengyuan , Liu Yijun
Published: September 2020

As an emerging material, metasurfaces open the door to a wide range of applications based on ultrasonic and elastic waves. However, most of the existing elastic metasurfaces have a fixed functionality and operate at a fixed frequency, which make them difficult to adapt to changing working requirements and/or environments. Although several recently proposed reconfigurable designs can relax this limitation, they either need laborious tuning or complex active control systems. In this work, by encoding multiple functionalities onto a single metasurface through operation frequencies, passive metasurfaces with switchable multifunctionalities are proposed and realized. Different wave manipulation functions of a single metasurface can be switched from one to another simply by changing the operation frequency. The design of these metasurfaces is realized using a systematic design approach based on topology optimization. Frequency‐coded multiple elastic wave manipulation functions, including wave beam steering and focusing, are numerically and experimentally demonstrated. Good agreement between the numerical simulations and experimental measurements is achieved. The proposed design strategy significantly enhances the functionalities and adaptivity of metasurfaces, moving them closer towards real‐world applications.
Ionic Liquid‐Based Stimuli‐Responsive Functional Materials
Authors: Cui Jiecheng , Li Yi , Chen Dong , Zhan Tian‐Guang , Zhang Kang‐Da
Published: September 2020

Ionic liquids (ILs) have many attractive properties. For example, their physical and chemical properties can be tuned by a judicious design of the cations and anions, making them ideal candidates for designable building blocks of stimuli‐responsive materials. Numerous IL‐based stimuli‐responsive materials have been developed by chemical modification (covalent, coordination, or ionic functionalization) or physical blending of ILs with other functional materials. The flexible tunability of ILs provides a great opportunity to achieve the desired physicochemical properties for task‐specific applications, such as sensing, display, gas capture, and so on. This review aims to address the recent advances in IL‐based stimuli‐responsive materials, which are categorized by the type of external stimuli, including gas‐responsive, organic solvent‐responsive, ion‐responsive, pH‐responsive, thermo‐responsive, photo‐responsive, and electro‐responsive materials.
Near‐Zero Power MOF‐Based Sensors for NO2 Detection
Authors: Small Leo J. , Henkelis Susan E. , Rademacher David X. , Schindelholz Mara E. , Krumhansl James L. , Vogel Dayton J. , Nenoff Tina M.
Published: September 2020

Detection and capture of toxic nitrogen oxides (NOx) is important for emissions control of exhaust gases and general public health. The ability to directly electrically detect trace (0.5–5 ppm) NO2 by a metal–organic framework (MOF)‐74‐based sensor at relatively low temperatures (50 °C) is demonstrated via changes in electrical properties of M‐MOF‐74, M = Co, Mg, Ni. The magnitude of the change is ordered Ni > Co > Mg and explained by each variant's NO2 adsorption capacity and specific chemical interaction. Ni‐MOF‐74 provides the highest sensitivity to NO2; a 725× decrease in resistance at 5 ppm NO2 and detection limit <0.5 ppm, levels relevant for industry and public health. Furthermore, the Ni‐MOF‐74‐based sensor is selective to NO2 over N2, SO2, and air. Linking this fundamental research with future technologies, the high impedance of MOF‐74 enables applications requiring a near‐zero power sensor or dosimeter, with the active material drawing <15 pW for a macroscale device 35 mm2 with 0.8 mg MOF‐74. This represents a 104–106× decrease in power consumption compared to other MOF sensors and demonstrates the potential for MOFs as active components for long‐lived, near‐zero power chemical sensors in smart industrial systems and the internet of things.
3D Printing Hydrogel Scaffolds with Nanohydroxyapatite Gradient to Effectively Repair Osteochondral Defects in Rats
Authors: Zhang Hui , Huang Haofei , Hao Guangrun , Zhang Yongsheng , Ding Hao , Fan Zengjie , Sun Luyi
Published: September 2020

Osteochondral (OC) defects pose an enormous challenge with no entirely satisfactory repair strategy to date. Herein, a 3D printed gradient hydrogel scaffold with a similar structure to that of OC tissue is designed, involving a pure hydrogel‐based top cartilage layer, an intermediate layer for calcified cartilage with 40% (w w−1) nanohydroxyapatite (nHA) and 60% (w w−1) hydrogel, and a 70/30% (w w−1) nHA/hydrogel‐based bottom subchondral bone layer. This study is conducted to evaluate the efficacy of the scaffold with nHA gradients in terms of its ability to promote OC defect repair. The fabricated composites are evaluated for physicochemical, mechanical, and biological properties, and then implanted into the OC defects in 56 rats. Overall, bone marrow stromal cells (BMSCs)‐loaded gradient scaffolds exhibit superior repair results as compared to other scaffolds based on gross examination, micro‐computed tomography (micro‐CT), as well as histologic and immunohistochemical analyses, confirming the ability of this novel OC graft to facilitate simultaneous regeneration of cartilage‐subchondral bone.
Human Retinal Microvasculature‐on‐a‐Chip for Drug Discovery
Authors: Ragelle Héloïse , Dernick Karen , Khemais Sonia , Keppler Cordula , Cousin Lucien , Farouz Yohan , Louche Chris , Fauser Sascha , Kustermann Stefan , Tibbitt Mark W. , Westenskow Peter D.
Published: September 2020

Retinal cells within neurovascular units generate the blood–retinal barrier (BRB) to regulate the local retinal microenvironment and to limit access to inflammatory cells. Breakdown of the endothelial junctional complexes in the BRB negatively affects neuronal signaling and ultimately causes vision loss. As new therapeutics are being developed either to prevent barrier disruption or to restore barrier function, access to physiologically relevant human in vitro tissue models that recapitulate important features of barrier biology is essential for disease modeling, target validation, and toxicity assessment. Here, a tunable organ‐on‐a‐chip model of the retinal microvasculature using human retinal microvascular endothelial cells with integrated flow is described. Automated imaging and image analysis methods are employed for facile screening of leakage mediators and cytokine inhibitors on barrier properties. The developed retinal microvasculature‐on‐a‐chip will enable improved understanding of BRB biology and provide an additional tool for drug discovery.
Rashba Effect in Functional Spintronic Devices
Authors: Koo Hyun Cheol , Kim Seong Been , Kim Hansung , Park Tae‐Eon , Choi Jun Woo , Kim Kyoung‐Whan , Go Gyungchoon , Oh Jung Hyun , Lee Dong‐Kyu , Park Eun‐Sang , Hong Ik‐Sun , Lee Kyung‐Jin
Published: September 2020

Exploiting spin transport increases the functionality of electronic devices and enables such devices to overcome physical limitations related to speed and power. Utilizing the Rashba effect at the interface of heterostructures provides promising opportunities toward the development of high‐performance devices because it enables electrical control of the spin information. Herein, the focus is mainly on progress related to the two most compelling devices that exploit the Rashba effect: spin transistors and spin–orbit torque devices. For spin field‐effect transistors, the gate‐voltage manipulation of the Rashba effect and subsequent control of the spin precession are discussed, including for all‐electric spin field‐effect transistors. For spin–orbit torque devices, recent theories and experiments on interface‐generated spin current are discussed. The future directions of manipulating the Rashba effect to realize fully integrated spin logic and memory devices are also discussed.
Tailoring the Surface of Perovskite through In Situ Growth of Ru/RuO2 Nanoparticles as Robust Symmetrical Electrodes for Reversible Solid Oxide Cells
Authors: Wang Junkai , Zhou Jun , Yang Jiaming , Neagu Dragos , Fu Lei , Lian Zhongjie , Shin Tae‐Ho , Wu Kai
Published: September 2020

Although numerous perovskite oxides can enhance the electrochemical activity via exsolved metallic nanoparticles on the surface, most of them can only be applied as catalysts in a reducing atmosphere. These nanoparticles cause serious performance degradation in oxidizing conditions due to the formation of low‐conductive metal oxides. This poses a big challenge to the design of highly active catalysts of electrochemical devices, especially for symmetrical solid oxide cells. Herein, based on the strategy of exsolved metallic nanoparticles in A‐site deficient perovskite, a unique and simple method is demonstrated for the synthesis of Ru/RuO2 nanoparticles on the surface of perovskite oxide via in situ growth. The electrode material (La0.75Sr0.25)0.9Cr0.5Mn0.45Ru0.05O3−δ (LSCMR) is designed through careful choice of composition and the core idea is to make use of the exsolved nanoparticles concept applied for the first time at both hydrogen electrode and oxygen electrode for symmetrical solid oxide cells. Inspired by exsolved Ru and RuO2, the surface‐decorated LSCMR exhibits significantly enhanced electrochemical activity for both H2 and O2, respectively, accompanied by high redox long‐term stability. Moreover, simple, low‐cost, and environmental‐friendly synthesis of Ru/RuO2 nanoparticles on the substrate of typical perovskites is realized with this in situ growth approach.
Impact of Mesoporous Silicon Template Pore Dimension and Surface Chemistry on Methylammonium Lead Trihalide Perovskite Photophysics
Authors: da Costa Viviana C.P. , Gonzalez‐Rodriguez Roberto , Frohna Kyle , Delport Géraud , Stranks Samuel D. , Canham Leigh T. , Coffer Jeffery L.
Published: September 2020

In influencing fundamental properties—and ultimately device performance—of lead halide perovskites, interfacial interactions play a major role, notably with regard to carrier diffusion and recombination. Here anodized porous Si (pSi) as well as porous silica particles are employed as templates for formation of methylammonium lead trihalide nanostructures. This allows synthesis of relatively small perovskite domains and comparison of associated interfacial chemistry between as‐prepared hydrophobic hydrideterminated functionalities and hydrophilic oxide‐terminated surfaces. While physical confinement of MAPbBr3 has a uniform effect on carrier lifetime, pore size (7–18 nm) of the silicon‐containing template has a sensitive influence on perovskite photoluminescence (PL) wavelength maximum. Furthermore, identity of the surface functionality of the template significantly alters the PL quantum efficiency, with lowest PL intensity associated with the H‐terminated pSi and the most intense PL affiliated with the oxideterminated pSi surface. These effects are explored for green‐emitting MAPbBr3 as well as infrared‐emitting MAPbI3. In addition, the role of silicon surface chemistry on the time‐dependent stability of these perovskites packaged within a given mesoporous template is also evaluated, specifically, a lack of miscibility between MAPbI3 and the H‐terminated pSi template results in a diffusion of this specific perovskite composition eluting from this porous matrix over time.
A Knotted Metamolecule with Axisymmetric Strong Optical Activity
Authors: Mai Wending , Kang Lei , Jenkins Ronald , Zhu Danny , Mao Chunxu , Werner Pingjuan L. , Chen Yifan , Werner Douglas H.
Published: September 2020

Optical activity is the ability of chiral materials to rotate linearly polarized electromagnetic waves. A knotted chiral metamolecule is introduced here that exhibits strong optical activity corresponding to a 90° polarization rotation of the incident waves. More importantly, the torus knot structure is intrinsically chiral and multifold axisymmetric. Consequently, the observed polarization rotation behavior is found to be independent of how the incident wave is polarized. The metamolecule is fabricated through selective laser melting and experimentally validated in the microwave spectrum. This work represents the first ever metamolecule to be reported that is intrinsically axisymmetric and capable of simultaneously exhibiting strong optical activity.
High Efficiency Emission of Eu2+ Located in Channel and Mg‐Site of Mg2Al4Si5O18 Cordierite and Its Potential as a Bi‐Functional Phosphor toward Optical Thermometer and White LED Application
Authors: Stefańska Dagmara , Dereń Przemysław J.
Published: September 2020

Eu2+ activated Mg2Al4Si5O18 cordierite phosphor is prepared by sol gel synthesis. The reduction process is carried out in a vacuum atmosphere. X‐ray diffraction, luminescence, decay times, quantum yield and emission thermal stability are studied. The emission from Eu2+ ions at different lattice sites, such as magnesium vacancies and inside the interstate channels, are identified and discussed. Considerations on crystal field strength and bond length allow to assign the blue emission band peak at 445 nm to Eu2+ ions located inside the interstitial channel, while the red band centered at 615 nm is related to Eu2+ ions on Mg site. It is found that the Mg2Al4Si5O18:Eu2+ phosphor excited by UV shows broad emission from 375 to 700 nm with high quantum efficiency (60%). The emission of Eu2+ in Mg2Al4Si5O18 has very good thermal stability, at 100 °C the intensity reaches 97% relative to the emission measured at room temperature. The investigations show that cordierite can be used as a temperature sensor with relative sensitivity of 0.45% at 400 °C. Moreover, the fabricated light‐emitting diode composed of 365 nm near‐UV chip and Mg2Al4Si5O18:Eu2+ phosphor exhibits bright white light with CIE coordinates (0.32, 0.34) for correlated color temperature of 6282 K and color rendering index of 82.
Bifunctional Nanoparticle‐Stabilized Hydrogel Colloidosomes Serve as both Extracellular Matrix and Bioactive Factor Delivery Vehicles
Authors: Tang Rui , Umemori Kentaro , Rabin Jacob , Alsberg Eben
Published: September 2020

Maintaining both cell–cell and cell–extracellular matrix (ECM) interactions is often a critical component of 3D tissue regeneration. In high‐density cell condensation systems, lack of appropriate cell–ECM interactions can result in limited and/or slow cell differentiation and tissue formation. To address these problems, a colloidosome microsphere system that is composed of a gelatin hydrogel core and a porous nanoparticle shell is developed. The colloidosome microsphere functions as an ECM and morphogen carrier for the induction of cartilage formation of high‐density human mesenchymal stem cell (hMSC) in 3D cultures. With the protection of the nanoparticle shell, the colloidosome microspheres can be readily suspended in aqueous solution without clumping, thus incorporated homogeneously within high‐density cell condensations. The gelatin‐based colloidosome microspheres stimulate chondrogenesis of hMSCs and degrade rapidly to facilitate ECM remodeling for new tissue formation. When loaded with human transforming growth factor‐β1, a potent chondrogenic morphogen, the colloidosomes serve as a bioactive factor delivery vehicle as well. The dual functionality of the colloidosomes as an ECM and a growth factor carrier effectively supports the chondrogenic differentiation of high‐density hMSC condensations. These capabilities render the colloidosomes a promising platform system amenable to large‐scale production of high‐density 3D tissue culture constructs.
Intracellular Antibody Delivery Mediated by Lipids, Polymers, and Inorganic Nanomaterials for Therapeutic Applications
Authors: Li Yamin , Li Peixuan , Li Raissa , Xu Qiaobing
Published: September 2020

Therapeutic antibodies, due to their high affinity and specificity toward their biological targets, may demonstrate reduced harmful side effects compared with traditional drug moieties. While most of the as‐yet clinically approved antibody therapeutics have targeted extracellular or membrane‐bound domains, the ability to target intracellular antigens with antibodies opens up tremendous opportunities for imaging, diagnosis, and therapeutic applications. Generally, delivery concerns have limited the ability to target intracellular antigens, as many antibodies cannot easily cross the cell membrane due to their size and surface chemistry. Delivery platforms have been explored to address this issue, including physical methods, fusion protein/peptide techniques, and synthetic carrier‐based systems. This review summarizes the progress of carrier‐based intracellular antibody delivery systems employing synthetic lipids, polymers, and inorganic nanomaterials. Antibodies targeting various epitopes have been loaded through adsorption, conjugation, or physical encapsulation strategies. Successful intracellular deliveries have been demonstrated largely through fluorescence imaging using dye‐labeled antibody cargos. Specific synthetic delivery platforms have great potential for ex vivo and in vivo therapeutic applications. Challenges and opportunities are further discussed for material scientists to explore in this research area.
Dependable Contact Related Parameter Extraction in Graphene–Metal Junctions
Authors: Gahoi Amit , Kataria Satender , Driussi Francesco , Venica Stefano , Pandey Himadri , Esseni David , Selmi Luca , Lemme Max C.
Published: September 2020

The accurate extraction and the reliable, repeatable reduction of graphene–metal contact resistance (RC) are still open issues in graphene technology. Here, the importance of following clear protocols when extracting RC using the transfer length method (TLM) is demonstrated. The example of back‐gated graphene TLM structures with nickel contacts, a complementary metal oxide semiconductor compatible metal, is used here. The accurate extraction of RC is significantly affected by generally observable Dirac voltage shifts with increasing channel lengths in ambient conditions. RC is generally a function of the carrier density in graphene. Hence, the position of the Fermi level and the gate voltage impact the extraction of RC. Measurements in high vacuum, on the other hand, result in dependable extraction of RC as a function of gate voltage owing to minimal spread in Dirac voltages. The accurate measurement and extraction of important parameters like contact‐end resistance, transfer length, sheet resistance of graphene under the metal contact, and specific contact resistivity as a function of the back‐gate voltage is further assessed. The presented methodology has also been applied to devices with gold and copper contacts, with similar conclusions.