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This article provides information on the integration of nanochemistry into secondary education curricula in Lower Saxony, Germany. It discusses the Nan_OS school laboratory setting, which aims to teach students about the properties, applications, opportunities, and risks of nanochemistry. The article also presents three innovative experiments that can be used in secondary education to introduce students to the synthesis and applications of nanoparticles. It emphasizes the importance of adapting school curricula to reflect current research and developments in nanotechnology and highlights the need for further development of experiments in the field of nanochemistry to support teachers in creating research-based lesson plans. [Extracted from the article]

In recent years, the agriculture practices have seen a growing interest in innovative technologies aimed at enhancing productivity while promoting sustainability. Nano-biofertilizers, a novel approach to crop nutrition, have emerged as a potential game-changer. This study is aimed comprehensively to uncover the potential and current utilization status of nano-biofertilizers in soil health improvement and sustainable enhancement of crop productivity. The methodology used in this study involved the application of systematic literature review (SLR) methods in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The review focused on scientific literature published from 2013 to 2023, utilizing databases such as ScienceDirect, Scopus, and PubMed. A total of 631 articles were identified through this process. Out of this pool, 10 articles were chosen based on their relevance and topic and they underwent a comprehensive and detailed review. The results showed that use of nano-biofertilizers improves the soil health, plant growth, and productivity significantly. The biological selenium nanoparticles (100 mg/mL) significantly increased the length and weight of spike, root, and shoot, grain quantity in spike, and 1000 grain weight by 5%–40% compared to control. Comamonas testosteroni biofertilizer combined with silver nanoparticles (AgNPs) could alleviate the salinity threatening plant growth. Nano-biofertilizers enhance plant growth, elevate their nutritional value, improve productivity, extend shelf life, and bolster their defenses against biotic and abiotic stress factors.

Senyawa bioaktif daun pegagan memiliki banyak manfaat. Senyawa ini memiliki sifat antioksidan, antimikroba dan antiinflamasi. Senyawa ini telah banyak digunakan untuk menyembuhkan beragam jenis penyakit. Oleh karena itu sangat berpotensi untuk dikembangkan sebagai bahan obat-obatan. Namun sifatnya sangat hidrofobik dan mudah terdegradasi. Untuk mengatasi masalah ini, pendekatan baru yaitu memperkecil ukuran partikelnya berorde nanometer, dapat dilakukan. Tujuan penelitian ini adalah mensintesa partikel senyawa bioaktif daun pegagan berukuran nanometer dan menguji pengaruh pemanasan dan tekanan terhadap diameter dan indeks polidispersitasnya. Senyawa bioaktif daun pegagan diekstrak menggunakan pelarut etanol. Nanopartikelnya disintesa menggunakan surfaktan tween 80. Pengaruh pemberian pemanasan dan tekanan terhadap diameter rata-rata dan indeks polidispersitasnya, diuji. Dari hasil yang diperoleh dengan menggunakan 6 ragam massa konsentrat hasil ekstrak: 4 mg, 5 mg, 6 mg, 7 mg, 8 mg, dan 9 mg yang masing-masing dilarutkan ke dalam 100 mL etanol, diameter rata-rata nanopartikelnya (dan indeks polidispersitas) masing-masing adalah 10,7 nm (0,266); 11,1 nm (0,240); 11,8 nm (0,395); 12,7 nm (0,086); 12,8 nm (0,299); dan 13,2 nm (0,464). Ketika nanopartikel ini dipanaskan pada temperatur 121oC dan tekanan 2 bar selama 15 menit, diameter rata-ratanya menjadi lebih besar: 11,0 nm; 11,3 nm; 12,4 nm; 12,9 nm; 13,5 nm; 14,1 nm; dan indeks polidispersitasnya menjadi lebih kecil: 0,196; 0,202; 0,242; 0,058; 0,274; dan 0,303. Hasil ini menunjukkan bahwa semakin besar massa konsentrat yang digunakan, semakin besar diameter rata-rata nanopartikel yang dihasilkan. Pemberian pemanasan dan tekanan, memperbesar diameter rata-rata nanopartikel dan memperkecil indeks polidispersitasnya.

High‐temperature gas cleaning is a challenge, especially when nanoparticles have to be separated from a hot gas stream. Thus, particle separation is often conducted after quenching the gas stream significantly. However, high‐temperature particle removal can substantially improve heat recovery in many existing industrial processes, as well as in upcoming pyrolytic processes and the flame‐based manufacturing of functional nanoparticles. This contribution describes the experimental results from a pilot‐scale high‐temperature electrostatic precipitator tasked with the removal of nanoparticles from a flue gas atmosphere between 400–800 °C. Additionally, the underlying phenomena are explained, and the future applications are outlined. Over the whole temperature range a reliable and energy‐efficient particle separation was observed. This technology combined with a high‐temperature heat exchanger can strongly reduce the primary energy consumption of high‐temperature processes. [ABSTRACT FROM AUTHOR]

Die Nutzung makromolekularer Gestaltungsmittel zur Regulierung von nicht‐kovalenten Bindungen im Nanoskalenbereich ist eine junge und emporkommende Herstellungsmethode für fortgeschrittene Nanostrukturen. Zum ersten Mal beschreiben wir eine Methode der Selbstorganisation, um eine Serie 2D‐plasmonischer Moleküle (PM) herzustellen, die Wasserstoffbrückenwechselwirkungen zwischen Paaren polymerbeschichteter Goldnanopartikel ausnutzen (Wasserstoff‐brückendonator und ‐akzeptor). Wir fanden heraus, dass aufgrund der Natur von Wasserstoffbrückenwechselwirkungen die Polymerinteraktion und die Solvatisierung während des Selbstorganisationsprozesses miteinander konkurrieren. Dies erwies sich als die wichtigste Bedingung, um die Koordinationszahl der PM zu kontrollieren. Wir führten eine umfassende Studie hinsichtlich des Lösungsmitteleffekts durch, die uns half, eine Serie präziser PM mit hoher Symetrie zu entwerfen und herzustellen. [ABSTRACT FROM AUTHOR]

Proteine und Enzyme sind äußerst vielseitige Biomaterialien, die aufgrund ihrer hohen Spezifität für Rezeptoren und Substrate, ihrer Abbaubarkeit, geringen Toxizität und insgesamt guten Biokompatibilität hervorragend für ein breites Spektrum medizinischer Anwendungen geeignet sind. Durch die Anordnung mehrerer nativer oder modifizierter Proteine zu nanometergroßen Protein‐Nanopartikeln können zusätzliche vorteilhafte Eigenschaften wie eine erhöhte Stabilität im Blutstrom erreicht werden. In diesem Aufsatz konzentrieren wir uns auf künstliche Nanopartikelsysteme, bei denen Proteine das Hauptstrukturelement sind und nicht nur als eingeschlossene Wirkstoffe transportiert werden. Während unter natürlichen Bedingungen lediglich bestimmte Proteine definierte Aggregate und Nanopartikel bilden, können durch chemische Modifikationen oder Veränderungen in der physikalischen Umgebung Nanopartikel aus vielen verschiedenen globulären Proteinen und Enzymen hergestellt werden. Fortschritte bei den Herstellungsmethoden von proteinbasierten Nanopartikeln haben zu einer neuen Generation von Nanosystemen geführt, die über einfache Wirkstofftransporter hinausgehen und vielfältige Anwendungen ermöglichen, wie z.B. gezielte Arzneimittelabgabe, Theranostik, Nanokatalyse und Proteintherapie. [ABSTRACT FROM AUTHOR]

Die Oberflächenchemie von Nanopartikeln ist ein wichtiger Schritt auf dem Weg vom Partikeldesign zur Anwendung in biologisch relevanten Umgebungen. Hier wird eine auf einer Doppelschicht (Bilayer) basierende Strategie für die Oberflächenmodifikation von hydrophoben Nanopartikeln vorgestellt, die diesen eine ausgezeichnete kolloidale Stabilität in wässriger Umgebung und einen guten Schutz gegen Auflösung verleiht und gleichzeitig eine Oberflächenfunktionalisierung durch einfache Carbodiimid‐Kopplungschemie ermöglicht. Wir haben das herausragende Potenzial dieser Strategie anhand von Upconversion‐Nanopartikeln (UCNPs) demonstriert, die ursprünglich mit Oleat beschichtet und daher nur in organischen Lösungsmitteln dispergierbar waren. Die hydrophobe Oleatbeschichtung bleibt dabei erhalten und bildet nach Zugabe von weiterem Oleat eine Doppelschicht. Dieser Ansatz schützt vor Lumineszenzlöschung durch Wassermoleküle, während der Einbau zusätzlicher Moleküle mit Aminogruppen in die Doppelschicht deren kolloidale Stabilität erhöht und die Funktionalisierbarkeit erleichtert. Die biologische Relevanz des Ansatzes wurde durch die Verwendung von zwei Modellfarbstoffen gezeigt, einem Photosensibilisator und einer Stickoxid‐ (NO−) Sonde, die, wenn sie an die Oberfläche der UCNPs gebunden sind, ihre Funktionalität zur Erzeugung von Singulett‐Sauerstoff bzw. zum Nachweis von intrazellulärem NO beibehalten. Wir stellen eine einfache und schnelle Methode zum Schutz und zur Funktionalisierung von anorganischen Nanopartikeln in biologischen Medien vor, die für die kontrollierte Oberflächengestaltung von Nanomaterialien für theranostische Anwendungen wichtig ist. [ABSTRACT FROM AUTHOR]

Magnetite magnetic nanoparticles are prepared using olive leaf extract as a green reducing and stabilizing agents. After reaction the product is heated up to get rid of the organic compounds and get pure magnetite nanoparticles. Differential scanning calorimetry is used to study the phase transformation as a function of heating temperature. Scanning electron microscope and high resolution transmission electron microscope show spherical and crystallized nanoparticles with a size of 5 nm. X‐ray diffraction and Raman and x‐ray photoelectron spectroscopy indicate the formation of Magnetite phase with high cristallinity and purity. The synthesized Magnetite nanoparticles are semiconductors with gap energy around 2 eV. Observed by transmission electron microscope graphite rods with stacked carbon disks are decorated with the prepared nanoparticles and show enhanced photocurrent. The vibrating sample magnetometer measurements indicate that the prepared Magnetite nanoparticles have superparamagnetic behavior. These results are very promising for clinical and water splitting applications. [ABSTRACT FROM AUTHOR]

In the present study, comparative analysis of glass ionomer and nanofillers in the performance of dental composite has been reviewed. In dental composite, a number of particulate fillers specifically nanoparticle are being tested and used. A new approach has been tried and investigated to replace expensive nanofillers with the other filler such as glass ionomer. There is a strong need to understand the scientific method, to conduct the clinical trial, and to perform the laboratory test to evaluate role of each parameter, constituent in the performance of dental composite. The present research reviewed the recent finding, possible opportunity and challenges for use of glass ionomer as replacement of nanofiller in dental composite. The existing literature on the favorable and non‐favorable side of glass ionomer is critically evaluated. The major aspect considered in the present review was to evaluate the surface roughness, mechanical properties and wear properties. The present article attempted to provide a state‐ of‐ the‐art analysis of fabrication method, surface treatment method and comparative analysis on role of particulate filler versus glass ionomer on the performance based on mechanical and wear testing mechanism. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Marine & Coastal Science is the property of Universitas Airlangga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Kolitis adalah penyakit yang mekanismenya didasari oleh infiltrasi sel radang ke mukosa saluran cerna. Sejumlah tanaman memiliki aktivitas sebagai antiinflamasi salah satunya adalah tanaman seledri (Apium groveolens). Kandungan fenolik dan flavonoid dari tanaman seledri, berpotensi memberikan efek proteksi pada lambung dan menurunkan iritasi lambung serta berpotensi digunakan sebagai antiinflamasi pada penyakit kolitis. Pengembangan tanaman seledri menjadi suatu bentuk sediaan obat tradisional memiliki beberapa kendala antara lain kelarutan yang kecil dari suatu ekstrak tanaman yang mengakibatkan absorbsi dan bioavailabilitas yang rendah, sehingga perlu dilakukan pengembangan sedian, seperti dalam bentuk nanopartikel. Penelitian ini dilakukan untuk mengetahui efek pemberian Suspensi Serbuk dan Nanopartikel Seledri terhadap kondisi kolitis pada mencit yang diinduksi DSS. Metode penelitian ini menggunakan mencit jantan galur DDY, yang dibagi menjadi 4 kelompok, kelompok 1 diberikan Suspensi Nanopartikel Seledri (NS) dosis 350 mg/kgBB selama 5 hari pada mencit yang diinduksi DSS 4%, kelompok 2 diberikan Suspensi Serbuk Seledri (SS) dosis 700 mg/kgBB selama 5 hari pada mencit yang diinduksi DSS 4%, kelompok 3 diberikan CMC-Na 0,25% selama 5 hari pada mencit yang diinduksi DSS 4%, dan kelompok 4 diberikan 5-Asam Aminosalisilat (5-ASA) dosis 100 mg/kgBB selama 5 hari pada mencit yang diinduksi DSS 4%. Kemudian dilakukan pengamatan skoring indeks aktivitas kolitis. Penelitian ini menunjukkan bahwa seledri dalam bentuk nanopartikel memberikan efek perbaikan pada kondisi kolitis yang signifikan dengan penuruan skor indeks aktivitas kolitis sebesar 73,62% dibandingkan dengan seledri dalam bentuk serbuk (p

Sowohl oberflächennahe Sauerstofffehlstellen als auch Hydroxylgruppen an der Oberfläche spielen eine entscheidende Rolle in der Katalyse. Dennoch bleiben die genauen Zusammenhänge durch die limitierte analytische Zugänglichkeit dieser Struktureigenschaften oft wenig verstanden. Zur selektiven Quantifizierung der sauren und basischen Oberflächenhydroxide wurde in dieser Studie deshalb eine Fluoridsubstitution am Beispiel zweier Serien von TiO2 (Rutil und P25) untersucht, welche eine zunehmende Dichte an Ti3+‐Sauerstofffehlstellen aufwiesen. Die Materialien sind durch gepulster Laserdefekt‐Engineering in Flüssigkeit (PUDEL) hergestellt worden. Aus EPR‐ und EEL‐Spektroskopie geht hervor, dass sich die lasergenerierten Ti3+ beim Rutil potentiell in der Nähe der Partikeloberfläche befinden, während diese beim P25 tiefer in den Partikeln vorzuliegen scheinen. Anhand der pH‐abhängigen Fluoridsubstitution zeigt sich, dass sich auf dem laserbehandelten Rutil zunehmend saure (verbrückende) Hydroxylgruppen gebildet haben, welche potentiell auf die Hydrierung der lasergenerierten, oberflächennahen Ti3+‐Zentren zurückgeht. Beim P25 blieb die Dichte an Hydroxylgruppen trotz nachweislicher Bildung von Ti3+‐Zentren bei der Laserbehandlung unverändert. Wir gehen davon aus, dass die hier eingesetzte pH‐abhängige Substitutionsmethode von Hydroxiden durch Fluoride zukünftig eine einfache und robuste Charakterisierung von Oberflächen‐OH und deren Korrelation mit Defekten in Metalloxiden zulassen wird. [ABSTRACT FROM AUTHOR]

Copyright of Teknika: Jurnal Sains dan Teknologi is the property of Teknika: Jurnal Sains dan Teknologi, Universitas Sultan Ageng Titayasa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Penelitian berbasis nanotechnology memiliki kemampuan dalam merekayasa sifat-sifat material. Salah satu material yang dijadikan nanopartikel adalah unsur Zink atau Seng (Zn) dalam bentuk oksidanya yaitu Zink Oksida (ZnO). C. taxifolia jenis rumput laut yang melimpah di Pantai Teluk Sepang, Kota Bengkulu dan belum dimanfaatkan secara optimal. Maka dari itu, penelitian ini bertujuan untuk menghasilkan nanopartikel ZnO dengan ekstrak C. taxifolia, menganalisa gugus fungsi nanopartikel ZnO C. taxifolia, menganalisa morfologi nanopartikel dan mengukur distribusi ukuran partikel. Nanopartikel Zink Oksida (ZnO) disintesis menggunakan metode reduksi. Material logam yang dijadikan nanopartikel yaitu ZnO (Zink Oksida) dan rumput laut Caulerpa taxifolia yang berperan sebagai reduktor, stabilisator dan capping agent. Nanopartikel ZnO C. taxifolia yang dihasilkan berupa bubuk ZnO berwarna putih susu (milky white) dan tidak memiliki aroma. Analisis gugus fungsi ZnO C. taxifolia menunjukkan bahwa pita serapan yang muncul tidak mendekati pita serapan ZnO, sedangkan pita serapan ZnO yang diperoleh telah berada dalam rentang nilai spektral ZnO dari hasil pengamatan. Hasil pencitraan SEM menggambarkan morfologi nanopartikel ZnO C. taxifolia yang terlihat tidak seragam serta didominasi dengan bentuk nanorod. Ukuran partikel ZnO sintesis ekstrak C. taxifolia cenderung bervariasi yaitu berkisar antara 1,28- 1764,23 nm yang berarti nanopartikel ZnO yang dihasilkan bersifat beragam. Kurva menunjukkan bahwa distribusi ukuran partikel ZnO C. taxifolia dengan rata-rata diameter 254,95 nm membuktikan bahwa ekstrak rumput laut C. taxifolia berhasil berperan sebagai agen penstabil, capping agent sekaligus agen pereduksi.

Limbah cangkang udang menimbulkan permasalahan polusi udara dan tumpukan sampah yang dihinggapi lalat. Pemanfaatan cangkang udang yang kaya protein dapat diekstraksi untuk dimanfaatkan sebagai serbuk penyedap rasa. Penelitian ini dilakukan untuk menentukan karakteristik dari filtrat ekstrak cangkang udang segar dan produk serbuk rasa udang, serta menentukan kondisi ekstraksi yang optimal pada penggunaan konsentrasi bromelain dan waktu refluk. Metode yang digunakan untuk pengambilan ekstrak udang dengan cara ekstraksi dengan alat refluk yang dilengkapi dengan pendingin yang terbagi menjadi dua tahap yaitu penambahan larutan garam dan enzim bromelain Gabungan filtrat ekstraksi dianalisis menggunakan GC-MS dan FT-IR. Selanjutnya filtrat diformulasikan menjadi serbuk penyedap rasa udang dengan beberapa bahan tambahan berupa tepung dan rempah-rempah. Selanjutnya, serbuk penyedap rasa dianalisis kadar air dan TEM. Ekstrak cangkang udang segar yang dianalsis mengandung senyawa dimetilamina dan trimetilamina yang merupakan kandungan protein, dengan kadar protein mencapai 28,984%. Selain protein, ekstrak juga mengandung asam lemak cangkang udang. Serbuk penyedap rasa udang yang dihasilkan mempunyai ukuran partikel sebesar 5 s.d 25 nm, dengan kadar air 11,11%. Kondisi operasi optimal ekstraksi protein dengan metode refluk pada kombinasi konsentrasi 2% katalis enzim bromelain pada suhu refluks 55 °C selama 1,5 jam. Ekstraksi menggunakan enzim bromelain secara bertahap memberikan kualitas flavor udang berupa serbuk kandungan protein dan lemak udang yang dipadu menjadi cita rasa spesifik dengan ukuran nanometer.

Copyright of Jurnal Veteriner is the property of Fakultas Kedokteran Hewan, Universitas Udayana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Manganese oxide nanomaterials (Mn3O4) have been prepared from manganese salts of two different anions and studied the role of metal precursor. Manganous sulphate monohydrate and manganese oxalate were used as manganese metal precursors. The obtained Mn3O4 samples were characterized by x‐ray diffraction, transmission electron microscope, Fourier transform infrared spectroscopy, UV‐vis absorbance spectra and photoluminescence excitation spectra. The x‐ray diffraction reveals that the prepared nanoparticles are crystalline in nature with tetragonal structure. In addition, the x‐ray diffraction concludes that the lattice parameters were altered with change in the precursors. The transmission electron microscope exhibits the prepared manganese oxide particles were nano in scale between the ranges of 25 nm to 60 nm. The Fourier transform infrared spectrum confirmed the presence of manganese oxide. The luminescence intensity of the samples varies depending upon the precursors used. The sample comprising of mixed precursors shows higher luminescence intensity than the samples containing MnSO4 ⋅ H2O and MnC2O4 precursors. This is owing to the fact that the surface of the sample has a lower concentration of hydroxyl ions, which was confirmed from the Fourier transform infrared spectra. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Marine & Coastal Science is the property of Universitas Airlangga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Der Hautarzt is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Automated image analysis has been applied to scanning electron micrographs (transmission mode; STEM) of metallic nanoparticles (silver and gold; about 10 nm to 20 nm). For a reliable particle identification, scanning electron microscopic images must be recorded with distinct contrast and resolution parameters. The particles were separated from the background and classified according to shape and size by machine learning (machine learning). Training images were created with model particles cut out of real electron microscopic images. The automated analysis of the particle size (expressed as area) was well possible, but overlapping particles could not be safely separated. The assignment of particle to six different shape classes (sphere, triangle, square, pentagon, hexagon, rod) by automated analysis was difficult. The fact that real particles never have an ideal geometrical shape but are always distorted or have rough edges or cropped tips is the fundamental reason of this problem. This effect also occurred with human image evaluators and poses a considerable obstacle in the training process for machine learning. Image analysis by machine learning techniques is difficult if different human evaluators disagree on the shape assignment of given particles because a proper training cannot be provided. [ABSTRACT FROM AUTHOR]

Binäre Mesokristalle ermöglichen die Kombination von Nanokristalleigenschaften in einer geordneten Überstruktur. Hier zeigen wir die simultane Selbstanordnung von Platin‐ und Eisenoxid‐Nanowürfeln zu μ‐großen 3D‐Mesokristallen mittels Gasphasendiffusion. Durch Zugabe geringer Mengen eines sekundären Partikeltyps, der auf nahezu identische Größe, Form und Oberflächenchemie zugeschnitten ist, erfolgte ein zufälliger Einbau von Fremdpartikeln in ein selbstorganisierendes Wirtgitter. Die zufällige Verteilung der binären Partikeltypen auf der Oberfläche und in ihrem Innern wurde mit Transmissions‐ und Rasterelektronenmikroskopie sichtbar gemacht. Die 20–40 μm großen binären Mesokristalle wurden mittels Weit‐ und Kleinwinkelstreuungstechniken genau charakterisiert, um eine Fernordnung auf atomarer Ebene im gesamten Kristall aufzuzeigen und Beweise dafür zu liefern, dass das Material aus einzelnen Bausteinen besteht. Durch Anpassung der Kristallisationsparameter ließ sich somit eine umgekehrte Überstruktur erzielen, bei der die inkorporierten Partikel und das Wirtgitter ihre Rollen tauschen. [ABSTRACT FROM AUTHOR]

This paper emphasis the improvement of mechanical properties of AA7075‐T651 using friction stir processing through localized surface modification by adding nano boron carbide particles. The reinforcement techniques such as the groove and blind hole methods were used by changing reinforcements of nano boron carbide and a matrix of AA7075‐T651 surface composites volume percentages (2 %, 4 %, and 6 %) along with tool rotational speed and processing speeds. Optical microscopy, scanning electron microscope and x‐ray diffraction analysis were used to examine the particle dispersion for the surface composites and to correlate with the enhanced mechanical properties. Results revealed that high input parameters have given grain coarsening and precipitate agglomeration and low input parameters provide poor nugget metal consolidation and no vertical material flow. The L9 orthogonal Array designed and optimized the process parameters for enhancing the surface properties of processed samples. Mechanical properties like ultimate tensile strength, yield strength, hardness, percentage of elongation and impact strength were evaluated for the groove friction stir processing method and blind‐hole friction stir processing methods. From the results, it has been observed that the blind‐hole technique resulted in higher hardness and the homogenous dispersion of nano boron carbide particles in the stir zone than the groove method. Consequently, for blind‐hole friction stir processing, grey relational analysis (GRA) and particle swarm optimization (PSO) approaches were proposed to optimise process parameters. From the compared optimization results between grey relational analysis and particle swarm optimization, particle swarm optimization approach was shown the best optimization results. Successively, the optimum condition in the respective experimentation is accomplished. Based on these observation and results, final validation tests were carried by changing the volume percentages of reinforcement keeping tool rotation speed and tool processing speed as constant. It is apparent that dynamic recrystallization in aluminium alloy at the processed zone due to presence of heterogeneous nucleation sites with nano boron carbide particles. [ABSTRACT FROM AUTHOR]

Propagation of grape rootstocks with cuttings is one of the routine processes of viticulture. Cutting studies for nursery production under nursery conditions often fall below the expected productivity level due to biotic and abiotic stress. To increase nursery yield remains on the agenda of vine researchers. Encapsulated silver nanoparticles (AgNPs) were produced by the green synthesis method from grape seed extract (Vitis vinifera L. cv Öküzgözü) with high phenolic content and silver nitrate (AgNO). The size of AgNPs was determined by Transmission Electron Microscope (TEM) as 10–50 nm and was not agglomerated and browned in colour. The effect of AgNPs on rooting of standard lignified 41B (Vitis vinifera L. cv. Chasselas × Vitis berlandieri) rootstocks pure and with Indole 3 Butyric Acid (IBA) (control, 0.5 mg L−1 AgNPs, 0.5 mg L−1 AgNPs 50 ppm IBA, 1 mg L−1 AgNPs, 1 mg L−1 AgNPs 50 ppm IBA and 50 ppm IBA) were tested. The effects of the applications on the cuttings in the greenhouse 1:1 perlite peat medium, leaf chlorophyll content, vegetative growth parameters and the effects on the vascular tissues were evaluated by micro tomography (microCT). Applications of pure AgNPs and combined with IBA did not altered the leaf chlorophyll content. While 1 mg L−1 AgNPs application, which was the closest level to 50 ppm IBA, provided the root and shoot development, while the application of 1 mg L−1 AgNPs encouraged the development of shoot most. The 1 mg L−1 AgNPs + 50 ppm IBA application resulted in the highest number of nodes in shoots developing from cuttings. In microCT analysis of rooted and unrooted grapevine cuttings, tissue damage was determined that was attributed to result in drying due to embolism and loss of nursery material. AgNPs applications are thought to increase the nursery success in grapevine rootstock cuttings. [ABSTRACT FROM AUTHOR]

Daun salam mengandung flavonoid sebagai antihipertensi, flavonoid yang diberikan secara peroral memiliki bioavailabilitas yang kurang baik karena kelarutan yang rendah dan tidak stabil terhadap faktor lingkungan. Salah satu upaya yang dapat dilakukan untuk mengatasi masalah tersebut adalah dengan memformulasikan dalam sediaan nanopartikel menggunakan polimer kitosan dan natrium tri-polifosfat (NaTPP). Penelitian ini bertujuan untuk mengkarakterisasi nanopartikel dari ekstrak etanol daun salam dengan variasi rasio konsentrasi kitosan. Ekstrak etanol daun salam diperoleh dengan cara ekstraksi menggunakan metode maserasi dengan pelarut etanol 96%. Hasil ekstrak dibuat koloid nanopartikel menggunakan teknik gelasi ionic menggunakan variasi ekstrak etanol daun salam: kitosan: NaTPP (1:1:1); (1:5:1); dan (1:10:1). Koloid nanopartikel yang terbentuk dikarakterisasi ukuran partikel, dan nilai zeta potensial. Hasil penelitian menunjukan bahwa ekstrak etanol daun salam positif mengandung flavonoid. Hasil karakterisasi nanopartikel ekstrak etanol daun salam menunjukkan bahwa formula F1, F2, dan F3 mempunyai ukuran partikel 284,2 ± 6,8; 410,6 ± 6,8; dan 630,1 ± 3,4 nm dan nilai zeta potensial F1, F2 dan F3 adalah 50,1 ± 4,3; 45,8 ± 0,7; dan 59,2 ± 1,2 mV. Semua formula menunjukan rentan karakterisasi sediaan nanopartikel (30 mV.

The design of a liquid/liquid contact apparatus necessitates the knowledge of fluid dynamics and mass transfer in the dispersion. Prediction of process parameters is challenging due to swarm and interfacial effects. Single drop investigations are suitable to enable a sophisticated dimensioning based on few simple experiments combined with published theories and correlations. In the first part of this article, the fundamentals of fluid dynamics and mass transfer in absence of interfacial effects were explained. Here, an overview of relevant interfacial phenomena and the influence of different substances typically occurring in technical applications as impurities or accompanying components is given. [ABSTRACT FROM AUTHOR]

Bajakah wood contains phenolic compounds, flavonoids, tannins, and saponins with anticancer activity. The discovery and development of new drugs require several stages. In the process, there are many possibilities of adding other substances to form new active substances or as solvents that allow drug preparations to be doubtful of halalness. Hence, it is necessary to analyze the critical point of halal ingredients. The purpose of this study was to determine the characteristics of the nanoparticles of bajakah wood (Spatholobus littoralis Hassk.) and to test the anticancer activity in several cancer cell cultures, as well as to analyze the critical point of halalness of the material. This research method is a composition test using chromatography and anticancer activity test using MTT. Analysis of the critical point of halal materials using hazard analysis critical control point (HACCP). The research was carried out at the Indonesian Engineering Nanotechnology Laboratory South Tangerang and the UGM Integrated Laboratory Sleman in July–December 2020. The results showed that bajakah wood nanoparticles contained pure water as a solvent, viscosity 0.08878 cP, scattering intensity 1.1059 cps, diameter 176.1+/−43.7 (nm). Cytotoxic test results showed IC50 against cell culture MCF7 1,063.28 (±114.98) g/mL, HepG2 53.34 (±0.35) g/mL, T47D 150.63 (±8.44) g/mL, WiDR 114.38 (±7.82) μg/mL, HTB 97.50 (±3.49) μg/mL, HeLa 182.95 (±36.22) μg/mL, and Vero 710.10 (±106.46) μg/mL. This study concludes that bajakah wood nanoparticles are not critical in terms of halal ingredients. At the same time, their anticancer activity is weak against breast cancer and uterine cervical cancer, medium categories against liver cancer and lung cancer, and is not toxic to normal cells. ANALISIS TITIK KRITIS KEHALALAN NANOPARTIKEL KAYU BAJAKAH (SPATHOLOBUS LITTORALIS HASSK.) SEBAGAI AGEN ANTIKANKER Kayu bajakah mengandung senyawa fenolik, flavonoid, tanin, dan saponin yang memiliki aktivitas antikanker. Penemuan dan pengembangan obat baru memerlukan beberapa tahapan. Dalam prosesnya terdapat banyak kemungkinan penambahan zat lain untuk membentuk zat aktif baru atau sebagai pelarut yang memungkinkan sediaan obat diragukan kehalalannya. Oleh sebab itu, perlu dilakukan analisis titik kritis kehalalan bahan. Tujuan penelitian ini mengetahui karakteristik sediaan nanopartikel kayu bajakah (Spatholobus littoralis Hassk.) dan menguji aktivitas antikanker pada beberapa kultur sel kanker, serta menganalisis titik kritis kehalalan bahan. Metode penelitian ini adalah uji komposisi menggunakan kromatografi dan uji aktivitas antikanker menggunakan MTT. Analisis titik kritis kehalalan bahan menggunakan hazard analysis critical control point (HACCP). Penelitian dilakukan di Laboratorium Nanovasi Rekayasa Indonesia Tangerang Selatan dan Laboratorium Terpadu UGM Sleman pada Juli–Desember 2020. Hasil penelitian menunjukkan sediaan nanopartikel kayu bajakah mengandung pelarut air murni, viskositas 0,08878 cP, scattering intensity 1,1059 cps, berdiameter 176,1+/−43,7 (nm). Hasil uji sitotoksik menunjukkan IC50 terhadap kultur sel MCF7 1.063,28 (±114,98) μg/mL, HepG2 53,34 (±0,35) μg/mL, T47D 150,63 (±8,44) μg/mL, WiDR 114,38 (±7,82) μg/mL, HTB 97,50 (±3,49) μg/mL, HeLa 182,95 (±36,22) μg/mL, dan Vero 710,10 (±106,46) μg/mL. Kesimpulan penelitian ini bahwa nanopartikel kayu bajakah bersifat tidak kritis dalam kehalalan bahan. Selain itu, aktivitas antikankernya lemah terhadap kanker payudara dan kanker serviks uteri, sedang terhadap kanker hati dan kanker paru, serta tidak toksik pada sel normal.

Aqueous‐phase synthetic route was applied for the preparation of magnesium aluminate spinel nanosheets with two‐dimensional nanostructure through a sol‐gel combustion approach, where triethanolamine was employed as a complexing agent and fuel. Results demonstrate that the as‐synthesized two‐dimensional nanosheets are well crystallized and show high purity. The pure magnesium aluminate nanoparticles with an average crystallite size of 25 nanometers were obtained at 1200 °C. Also, the two‐dimensional magnesium aluminate powder contain nanosheets with thicknesses in the 20 nanometers–30 nanometers range, and the lateral size is in the range of ∼10 micrometers–30 micrometers. [ABSTRACT FROM AUTHOR]

Sintesis pasir besi lampanah Aceh Besar menjadi nanopartikel magnetite besi oksida menjadi tujuan utama dalam penelitian ini untuk mengamati struktur Kristal yang dimilikinya. Sifat Kristalin yang tinggi ketika terjadi perubahan fisis dari material menjadikan kajian ini layak untuk diteliti. Melalui teknik pemisahan menggunakan magnet batang, pasir besi dari alam dipisahkan dari pengotor lalu disaring dengan ayakan yang berukuran 200 mesh. Pasir besi berkualitas baik disintesis dengan menggunakan metode kopresipitasi yang mana pasir besi dilarutkan ke dalam 12 M Asam Klorida 37 % v/v. Larutan tersebut diaduk dan disaring, kemudian hasil larutan dicampurkan dengan 6,5 M ammonia dengan perbandingan ratio campuran 1:7. Melalui proses aduk dan saring, hasil endapan kemudian dikeringkan. Berdasarkan hasil uji XRD, SEM dan Cacah magnetik didapati karakteristik nanopartikel magnetite besi oksida. Berdasarkan data XRD, didapati sudut 2 thetanya 30,105o; 35,45o dan 62,585o dengan indek miller [hkl]: [220], [311] dan [440]. Nilai [hkl] ini menunjukkan bahwa nanopartikel magnetite dari pasir besi Lampanah memiliki struktur kristal Kubik dengan struktur kisinya FCC (Face Center Cubic). Berdasarkan uji SEM, morfologi nanopartikel magnetite besi oksida berbentuk tidak seragam dengan ukuran partikel yang relatif tidak sama berada dalam rentang 800 nm sampai 3000 nm. Sedangkan untuk cacah medan magnetik dalam bentuk pasir besi didapati nilai cacahannya 0,03 mT sedangkan dalam bentuk nanopartikel magnetite diperoleh 0,022 mT. Kesimpulan yang didapati bahwa struktur Kristal dari pasir besi Lampanah semakin terlihat ketika ukuran besi oksida menjadi nanopartikel magnetite. Langkah pengoptimalan dalam preparasi pasir besi menjadi nanopartikel magnetite diperlukan agar ukuran partikelnya di bawah < 100 nm sehingga dapat diaplikasinya dalam bidang elektronik, kesehatan dan sebagainya.

Kanker adalah penyakit tidak menular yang menyebabkan mordibitas dan mortalitas di seluruh wilayah dunia. Pengobatan kanker menjadi hal penting dalam mengurangi tingginya jumlah angka kematian (mortalitas) karena penderita penyakit kanker. Salah satu pengobatan kanker adalah dengan menggunakan obat kemoterapi cisplatin. Akan tetapi obat cisplatin memiliki efek samping yaitu nefrotoksisitas,ototoksisitas,neurotoksisitas,hemotologistoksisitas,kardiotoksisitas, dan hepatotoksisitas. Oleh karena itu kombinasi cisplatin dalam nanopartikel albumin dan modifikasi ikatan menggunakan asam folat sebagai solusi alternatif meminimalisir efek toksik yang dihasilkan. Tujuan penelitian untuk mengetahui efek toksisitas formulasi obat cisplatin dengan kombinasi nanopartikel bovine serum albumin (BSA) dan asam folat melalui metode Brine Shrimp Lethality Test (BSLT). Metode penelitian yang dilakukan yaitu sintesis nanopartikel BSA (NP-BSA), Sintesis NP-BSA dengan Obat Cisplatin (CP-NP-BSA), Sintesis Asam Folat dengan Kombinasi CP-NP-BSA (As-CP-NP-BSA). Kemudian dilakukan uji toksisitas dengan metode BSLT untuk mengetahui kadar toksisitas nanopartikel BSA serta pengaruh penambahan asam folat dalam obat cisplatin dalam nanopartikel. Hasil diperoleh bahwa absorbansi dari Spektrofotometer UV-Vis panjang gelombang 358 nm As-CP-NP-BSA sebesar 0,86. Kadar toksisitas pada NP-BSA dengan nilai LC50 69,23 ppm sedangkan kadar toksisitas As-CP-NP-BSA LC50 56,56 ppm. Nanopartikel yang terdiri dari kombinasi bovine serum albumin, cisplatin dan asam folat dapat dijadikan sebagai kandidat obat antikanker.

The design of a liquid‐liquid contact apparatus necessitates the knowledge of fluid dynamics and mass transfer in the dispersion. Since swarm effects and interfacial phenomena induce complex interactions the prediction of process parameters is a challenging task. Single‐drop investigations are suited to enable a sophisticated dimensioning based on few simple experiments in combination with published theories and correlations available from literature. This two‐part article deals with the fundamentals of fluid dynamics and mass transfer of single droplets and evaluates occurrence and impact of interfacial effects as well as impurities typical for technical applications. [ABSTRACT FROM AUTHOR]

9 %–12 % Cr ferritic/martensitic steels with a good long‐term creep strength at temperatures up to 650 °C and higher are being developed in order to increase steam temperature of coal‐fired power plants.Thermomechanical treatment can effectively enhance the mechanical properties of high‐Cr ferritic/martensitic steels mainly due to plenty of nano‐sized precipitates produced by thermomechanical treatment. Nano‐sized precipitates in an 11 % Cr ferritic/martensitic steel produced by a thermomechanical treatment, including warm rolling at 650 °C plus tempering at 650 °C for 1 h, were investigated by transmission electron microscopy. The average size of precipitates in the steel after the thermomechanical treatment was determined to be about 30 nm in diameter, which is only one‐third of the average size of precipitates in the steel with the normalized and tempered condition. A large number of Cr‐rich precipitates having an average diameter of about 25 nm in the steel produced by the thermomechanical treatment were identified as Cr‐rich M2C carbide with a hexagonal crystal structure, rather than M23C6 or MX phase. The plenty of nano‐sized Cr‐rich M2C carbides were dominant phase in the steel after the thermomechanical treatment. The reason why prior precipitate phase formed in the steel during the thermomechanical treatment was Cr‐rich M2C carbide is also discussed. [ABSTRACT FROM AUTHOR]

Retikuläre Materialien sind von großem Interesse für Anwendungen in der Katalyse und Stofftrennung sowie der Gasspeicherung und gezielten Wirkstoffzufuhr. Diese offenporigen, ausgedehnten Gerüststrukturen können durch Kristallstrukturdesign auf spezifische Anwendungen zugeschnitten werden. Die Implementierung dieser Materialien in Anwendungsumgebungen erfordert jedoch eine Strukturierung über ihr Kristallgitter hinaus, um die Funktionalität auf molekularer Ebene effektiv mit der makroskopischen Welt zu verbinden. Um diese Barriere zu überwinden, werden als nächster Schritt Strategien für die Strukturierung retikulärer Materialien im Nano‐, Meso‐ und Volumenregime benötigt. In diesem Aufsatz geben wir einen Einblick in die jüngsten Fortschritte für die Herstellung von retikulären Materialien über allen Längenskalen, mit dem Fokus auf Selbstorganisationsstrategien und extern kontrollierten Ansätzen. Wir erwarten, dass bedeutende Forschungsfortschritte bei der Anwendung dieser beiden Ansätze in Verbindung mit retikulären Materialien erreicht werden und diese dabei helfen werden, wichtige Bedürfnisse der Gesellschaft zu bewältigen. [ABSTRACT FROM AUTHOR]

This research article investigates carefully the effect of different nanoparticles zinc oxide (ZnO), graphene, and combinations thereof in API base oil group ΙΙ (PBO−GΙΙ). The morphology of zinc oxide and graphene nanomaterials are depicted by transmission electron microscopy. Sonication treatment and dispersion stability investigations are carried out after the preparation of nanoparticles with surfactant (oleic acid) and pure base oil group ΙΙ for certain concentrations. Oil formulations tested by using a four‐ball machine to find out the coefficient of friction (COF), wear scar diameter (WSD), and specific wear rate (SWR) for each sample. Additionally, scarred balls are characterized by using field emission scanning electron microscopes (FE‐SEM), energy‐dispersive x‐ray spectroscopy (EDX/EDS), elements mapping, Raman spectroscopy, and a three‐dimensional surface texture analyzer to study the morphology of sliding balls after the tribological experiments and to confirm the presence of (zinc oxide+graphene) on the machined balls. Surface roughness measurements implemented for identifying surface finish of scarred balls. The experimental results and surface analyses showed that (0.4 wt.% ZnO+0.2 wt.% graphene) nanolubricant has outperformed behavior compared to base oil group ΙΙ due to the formation of tribofilm on the contacting surfaces during sliding motion. [ABSTRACT FROM AUTHOR]

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Pemanfaatan rumput laut untuk disintesis secara biologi (biosintesis) menjadi nanopartikel logam telah banyak dilakukan sebagai alternatif produksi ramah lingkungan. Penelitian ini bertujuan mendapatkan nanopartikel seng oksida (ZnO) melalui biosintesis ekstrak rumput laut coklat Sargassum sp. dan Padina sp. dengan menggunakan prekursor zink nitrat 10 mM pada variasi pH larutan 8-12. Analisis meliputi gugus fungsi, distribusi ukuran partikel, morfologi, dan kristalinitas. Hasil penelitian menunjukkan gugus fungsi hidroksil dan sulfat polisakarida berperan dalam proses reduksi kation Zn2+ membentuk nanopartikel ZnO sedangkan protein untuk kestabilan nano-partikel. Nanopartikel ZnO dari biosintesis ekstrak Sargassum sp. dan Padina sp. masing-masing menghasilkan rata-rata ukuran partikel berkisar antara 1.396,53-3.090,50 dan 655,91-3.253,06 nm. Distribusi ukuran sudah homogen namun belum memenuhi besaran ukuran nanometer. Rata-rata ukuran partikel terkecil terdapat pada pH 10 dan 9. Kisaran % mass elemen Zn dan O nanopartikel ZnO biosintesis ekstrak Sargassum sp. yang mirip standar adalah pada pH 10 yaitu 95,98% dan 4,02% sedangkan dari ekstrak Padina sp. pada pH 9 dengan 94,67% dan 5,33%. Struktur kristalinitas menunjukkan ZnO biosintesis ekstrak Sargassum sp. pada pH 8-11 dan Padina sp. pada pH 9 hampir seluruhnya memiliki puncak dengan nilai sudut 2q yang hampir sama, dan setelah dikonfirmasi dengan program Match! 3 menunjukkan struktur kristal ZnO wurtzit berbentuk heksagonal. Perlakuan terbaik ZnO biosintesis dari ekstrak Sargassum sp. dan Padina sp. adalah pada kondisi pH 10 dan 9.

Nanopartikel magnetis ZnFe2O4 telah disintesis menggunakan metode presipitasi untuk degradasi rhodamine B dengan penyinaran cahaya UV dan cahaya tampak. Analisis pola difraksi sinar-X dan spektrum Fourier Transform Infrared (FTIR) menunjukkan pembentukan kubik spinel ZnFe2O4 dengan ukuran kristalit sekitar 13 nm. Spektrum absorpsi dalam rentang cahaya UV (200 nm) sampai cahaya tampak (~ 600 nm) dan celah energi 2,04 eV teramati dari pengukuran spektrofotometer UV-Vis. Sifat magnetik nanopartikel diukur menggunakan vibrating sample magnetometer (VSM) menunjukkan sifat magnet lemah yang sesuai untuk aplikasi magnetis fotokatalis. Nanopartikel ZnFe2O4 menunjukkan aktivitas fotokatalisis dengan cahaya UV maupun cahaya tampak untuk degradasi rhodamine B dengan konstanta laju reaksi 8,2 x 10-3 /menit dan 4,5 x 10-3/menit.

Latar belakang: Nanopartikel merupakan partikel dengan rentang ukuran diameter antara 1 - 1000 nm. Nanopartikel Artesunat-Khitosan diformulasikan menjadi nanopartikel menggunakan metode gelasi ionik-pengering beku ditujukan untuk melindungi bahan obat dari peruraian selama proses pembuatan. Untuk memperoleh produk dari pengeringan beku yang baik, optimasi lioprotektan sangat diperlukan. Tujuan: Tujuan dari penelitian ini adalah untuk mempelajari karakteristik fisik nanopartikel Artesunat-Khitosan yang diformulasikan dengan tiga lioprotektan yang berbeda: sukrosa, trihalosa dan maltodekstrin menggunakan metode pengeringan beku. Metode: Pembuatan nanopartikel dilakukan menggunakan gelasi ionik dengan tripolifosfat sebagai crosslinker. Evaluasi nanopartikel kering meliputi: morfologi, sifat fisik, spektrum inframerah dan redispersabilitas. Hasil: Data deferential thermal analysis (DTA) menunjukkan, penambahan lioprotektan menjebak artesunat dalam sistem nanopartikel chitosan, dimana formula tanpa penambahan lioprotektan tidak ditemukan artesunat di dalam matriks chitosan. Pemeriksaan morfologi menggunakan scanning electron microscopy (SEM) menunjukkan nanopartikel dengan 2,5% maltodextrin memiliki permukaan yang halus dan bentuk yang speris. Selain itu, maltodextrin menunjukkan efek perlindungan selama pengeringan beku, laju pengendapan yang lebih lambat dan kemampuan untuk redipersi yang lebih baik dibandingkan dengan sukrosa dan trehalosa. Lioprotektan dengan konsentrasi tinggi menunjukkan redispersibilitas nanopartikel artesunat-chitosan yang lebih baik. Kesimpulan: Berdasarkan hasil penelitian ini, dapat disimpulkan bahwa dengan penambahan lyoprotectant mempengaruhi karakterisitik nanopartikel artesunat-chitosan.

Continuous irradiation during photodynamic therapy (PDT) inevitably induces tumor hypoxia, thereby weakening the PDT effect. In PDT‐induced hypoxia, providing singlet oxygen from stored chemical energy may enhance the cell‐killing effect and boost the therapeutic effect. Herein, we present a phototheranostic (DPPTPE@PEG‐Py NPs) prepared by using a 2‐pyridone‐based diblock polymer (PEG‐Py) to encapsulate a semiconducting, heavy‐atom‐free pyrrolopyrrolidone‐tetraphenylethylene (DPPTPE) with high singlet‐oxygen‐generation ability both in dichloromethane and water. The PEG‐Py can trap the 1O2 generated from DPPTPE under laser irradiation and form a stable intermediate of endoperoxide, which can then release 1O2 in the dark, hypoxic tumor microenvironment. Furthermore, fluorescence‐imaging‐guided phototherapy demonstrates that this phototheranostic could completely inhibit tumor growth with the help of laser irradiation. [ABSTRACT FROM AUTHOR]

Copyright of Gesunde Pflanzen is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Complex structures from nanoparticles are found in rocks, soils, and sea sediments but the mechanisms of their formation are poorly understood, which causes controversial conclusions about their genesis. Here we show that graphene quantum dots (GQDs) can assemble into complex structures driven by coordination interactions with metal ions commonly present in environment and serve a special role in Earth's history, such as Fe3+ and Al3+. GQDs self‐assemble into mesoscale chains, sheets, supraparticles, nanoshells, and nanostars. Specific assembly patterns are determined by the effective symmetry of the GQDs when forming the coordination assemblies with the metal ions. As such, maximization of the electronic delocalization of π‐orbitals of GQDs with Fe3+ leads to GQD‐Fe‐GQD units with D2 symmetry, dipolar bonding potential, and linear assemblies. Taking advantage of high electron microscopy contrast of carbonaceous nanostructures in respect to ceramic background, the mineralogical counterparts of GQD assemblies are found in mineraloid shungite. These findings provide insight into nanoparticle dynamics during the rock formation that can lead to mineralized structures of unexpectedly high complexity. [ABSTRACT FROM AUTHOR]

Fully utilizing solar energy for catalysis requires the integration of conversion mechanisms and therefore delicate design of catalyst structures and active species. Herein, a MOF crystal engineering method was developed to controllably synthesize a copper–ceria catalyst with well‐dispersed photoactive Cu‐[O]‐Ce species. Using the preferential oxidation of CO as a model reaction, the catalyst showed remarkably efficient and stable photoactivated catalysis, which found practical application in feed gas treatment for fuel cell gas supply. The coexistence of photochemistry and thermochemistry effects contributes to the high efficiency. Our results demonstrate a catalyst design approach with atomic or molecular precision and a combinatorial photoactivation strategy for solar energy conversion. [ABSTRACT FROM AUTHOR]

The pre‐targeted imaging of enzyme activity has not been reported, likely owing to the lack of a mechanism to retain the injected substrate in the first step for subsequent labeling. Herein, we report the use of two bioorthogonal reactions—the condensation reaction of aromatic nitriles and aminothiols and the inverse‐electron demand Diels–Alder reaction between tetrazine and trans‐cyclooctene (TCO)—to develop a novel strategy for pre‐targeted imaging of the activity of proteases. The substrate probe (TCO‐C‐SNAT4) can be selectively activated by an enzyme target (e.g. caspase‐3/7), which triggers macrocyclization and subsequent in situ self‐assembly into nanoaggregates retained at the target site. The tetrazine‐imaging tag conjugate labels TCO in the nanoaggregates to generate selective signal retention for imaging in vitro, in cells, and in mice. Owing to the decoupling of enzyme activation and imaging tag immobilization, TCO‐C‐SNAT4 can be repeatedly injected to generate and accumulate more TCO‐nanoaggregates for click labeling. [ABSTRACT FROM AUTHOR]

The remarkable resilience of N‐heterocyclic carbene (NHC) gold bonds has quickly made NHCs the ligand of choice when functionalizing gold surfaces. Despite rapid progress using deposition from free or CO2‐protected NHCs, synthetic challenges hinder the functionalization of NHC surfaces with protic functional groups, such as alcohols and amines, particularly on larger nanoparticles. Here, we synthesize NHC‐functionalized gold surfaces from gold(I) NHC complexes and aqueous nanoparticles without the need for additional reagents, enabling otherwise difficult functional groups to be appended to the carbene. The resilience of the NHC−Au bond allows for multi‐step post‐synthetic modification. Beginning with the nitro‐NHC, we form an amine‐NHC terminated surface, which further undergoes amide coupling with carboxylic acids. The simplicity of this approach, its compatibility with aqueous nanoparticle solutions, and its ability to yield protic functionality, greatly expands the potential of NHC‐functionalized noble metal surfaces. [ABSTRACT FROM AUTHOR]