, Nanotechnology Fig. 2. Capillarity-induced skin folding. (A) Optical microscope image of an array of wrinkles and folds around the boundary of a water droplet placed on a wrinkled surface (t = 20 min, ε ≈ −0.03). The blue arrow indicates a water filament. (B) Schematic illustrations of the wrinkle-to-fold transition of the skin due to surface tension forces of water. Representative AFM images and the line profiles are shown below the illustrations. (C) Schematic illustrations and optical microscope images showing the evolution of localized folds with increasing ε (t = 10 min). A water droplet was placed on the surface before compression; the blue arrow and red triangles indicate the formation of a water filament and localized folds, respectively. (D and E) The peak-to-peak distance of wrinkles (LW) and folds (LF) and the length (l) and spacing (s) of the folds as a function of t. (E, Inset) Schematic illustration showing the top view of an array of folds at the boundary. (F) LW and LF as a function of |ε| (t = 3 min). (F, Inset) Line profiles of the folds for |ε| ≈ 0.02, 0.08, and 0.17. (Scale bars: A, 10 μm; B, 5 μm; and C, 50 μm.). Credit: Nagashimaa S, Haa HD, Kima DH, Košmrljb A, Stone HA, Moon M-W (2017) Spontaneous formation of aligned DNA nanowires by capillarity-induced skin folding. Proc Natl Acad Sci USA 114:24 6233-6237. Journal information: Proceedings of the National Academy of Sciences “This phenomenon can be considered a lithography-free method that allows for ready fabrication of arrays of nanomaterials, where their size, length, and periodicity could robustly be tuned,” he continues. “Moreover, not only water but other liquids could be used to carry nanomaterials and to induce the wrinkle-to-fold transition.”Moon describes several examples of potential de novo fabrication and analysis techniques, including nanoscale lithography, nanoimprint, growth by chemical vapor deposition, and chemical reaction. “Our method can potentially be used for the fabrication of 1-dimensional nanowires or nanoarrays for application to DNA analysis with very dilute or small amounts of DNA; DNA templates as new metal or ceramic nanostructures; and DNA treatment devices for healing modified DNA. In addition, one can adopt this technique to handle protein, blood, or nanoparticles at nanoscale.”Košmrlj and Stone tell Phys.org that one area of planned research is focused on nonlinear analysis and modeling for improved quantitative understanding of the capillarity-induced wrinkle-to-fold transition. “Since our system is composed of the mechanical behavior of the fold transition triggered by liquid surface tension, the wrinkle-to-fold transition that we’ve found is associated with large deformations where conventional linear elasticity theory does not apply. While the basic mechanisms can be explained within the linear theory, quantitative comparison with experiments can only be achieved by taking into account geometrical and material nonlinearities. We are therefore performing numerical simulations by coupling liquid surface tension and solid deformation, as well as performing analysis with perturbation series, where nonlinearities of elastic structures can be studied systematically.””I also think that the challenges ahead are to find how to achieve larger areas for DNA pattern formation,” Moon says. “In fact, our latest results—obtained after this PNAS article was accepted—shows some impressive progress for the region with wrinkle-to-fold transition in larger areas, such as the entire area underneath a water droplet. Another area to be studied, Moon continues, concerns the fact that biological morphogenesis of skin–substrate systems are ubiquitous in organisms where water is a major constituent. “We’re trying to find situations where our findings are applicable. Active collaborations with experts in the field would be helpful.” The researchers might also investigate materials other than PDMS. “Yes. other polymers can work if they possess the basic factors to govern the fold transition, these being the thinness of the nano-skin and soft body materials, and surface hydrophilicity to ensure sufficient surface reaction with liquid,” Moon notes. Assistant Professor and lead author So Nagashima, Assistant Professor Andrej Košmrlj, Donald R. Dixon ’69 and Elizabeth W. Dixon Professor Howard A. Stone, and Principal Research Scientist Myoung-Woon Moon discussed the paper they and their co-authors published in Proceedings of the National Academy of Sciences. “I think that the most challenging aspect of devising our method for utilizing a thin skin template that responds to water by dynamically changing its surface morphology was finding the conditions where the wrinkle-to-fold transition occurs,” Moon tells Phys.org. “The critical conditions as a function of the applied strain, initial wrinkle geometries, and thickness of the skin layer determined by oxygen plasma treatment duration were difficult to find.” Moon adds that the observation technique for the dynamic transition was limited to only optical microscopes whose highest optical resolution falls between 100 to 1000 nm in the width of nanowires, this being due to the dynamic transition taking place at the submicron scale.When inducing a template surface wrinkle-to-fold transition by exploiting the capillary forces of water containing DNA molecules, Stone points out, the observation that water changes the wrinkle-to-fold transition is new. “As far as we know, ours is the first study to show this effect, as is demonstrating one use of such folds for the alignment of DNA. Moreover, control of surface tension or resultant capillary forces and the area for fold formation is relatively hard—and by adding DNA molecules to water, it appears that the surface tension is changed, so the fold transition length was shorter.”Template preparation used an oxygen plasma treatment of prestretched polydimethylsiloxane (or PDMS, a polymeric organosilicon compound) substrates for varying durations. “In fact,” Moon explains, “the manipulation of PDMS with prestretching strain is a relatively well-developed method as is the oxygen plasma treatment: both have been discussed in the literature. We can make the samples with various sizes of a few millimeters to a few centimeters, which can be also made on much larger area.” Moon notes that the researchers can also vary polydimethylsiloxane’s mechanical properties—to make it more stretchable, soft or flexible—by changing the ratio of elastomer and cross-linker for PDMS preparation. Fig. 1. Spontaneous formation of aligned DNA nanowires. (A) Schematic illustrations of the spontaneous formation of an array of DNA nanowires by the skin folding induced by water filaments containing DNA molecules. (B) Sequential optical microscope images of a droplet of DNA solution spreading over wrinkles (t = 5 min, ε ≈ −0.03); the wrinkle-to-fold transition occurs at the boundary and propagates with the edge of the droplet. (C) AFM image of an array of DNA nanowires extending from the boundary (t = 2 min, ε ≈ −0.02). The line profiles for each region are shown next to the image. (Scale bars: B, 50 μm and C, 4 μm.). Credit: Nagashimaa S, Haa HD, Kima DH, Košmrljb A, Stone HA, Moon M-W (2017) Spontaneous formation of aligned DNA nanowires by capillarity-induced skin folding. Proc Natl Acad Sci USA 114:24 6233-6237. Citation: Of wrinkles and wires: Capillarity-induced skin folding spontaneously forms aligned DNA nanowire (2017, June 19) retrieved 18 August 2019 from https://phys.org/news/2017-06-wrinkles-wires-capillarity-induced-skin-spontaneously.html Other possible future research interests and additional innovations mentioned by the authors include:- theoretical analysis to elucidate the underlying physics related to the water-induced surface folding- exploit the underlying physics to develop a robust and mass fabrication method for inducing the wrinkle-to-fold transition- find and discuss morphological changes in nature where water is likely a key factor- apply the current study’s results to DNA analysis or DNA drug devices- 2-D/3-D sensors, diagnostic tools, and drug-release systems- templates for fabricating 1-dimensional nanomaterials- methods for local patterning”I believe that this work is beneficial to materials science for nanowire templates, mechanics for fluidic channels, and biology for quantitative analysis of DNA or other biomolecules,” Moon concludes. Explore further , Journal of Biomedicine and Biotechnology More information: Spontaneous formation of aligned DNA nanowires by capillarity-induced skin folding, PNAS (2017) 114:24 6233-6237, doi:10.1073/pnas.1700003114Related:1DNA nanowire fabrication, Nanotechnology (2006) 17:R14m https://core.ac.uk/download/pdf/1559975.pdf2DNA-Templated Self-Assembly of Protein Arrays and Highly Conductive Nanowires, Science (2003) 301:5641 1882-1884, doi:10.1126/science.10893893Nanowire-Based Sensors for Biological and Medical Applications, IEEE Transactions on NanoBioscience (2016) 15:3 186-199, doi:10.1109/TNB.2016.25282584DNA-Based Applications in Nanobiotechnology, Journal of Biomedicine and Biotechnology (2010) Article ID 715295, doi:10.1155/2010/7152955Nanowire nanosensors, Materials Today (2005) 8:5, doi:10.1016/S1369-7021(05)00791-1 A key aspect of the study was confirming that the new method reliably manipulates DNA nanowire size, geometry, and alignment. “By adjusting the conditions for stretching strain, plasma treatment duration, and post-compression of the stretched PDMS, DNA nanowires can be a half cylinder, a perfect cylinder, or undulated wire shape,” Moon tells Phys.org. “By changing the wrinkle geometries such as the amplitude—which is governed by the strain—one can control the distance between wires in the fold channel.” Wider distances between wires, he continues, can be accomplished by compressing the PDMS less, while compressing the substrate more yields smaller distances.To address these challenges, the scientists discovered a transformation resulting from capillary forces that act at the edge of a water droplet that can, with only 1% compression, transform wrinkles into folds, which in the absence of a liquid drop form only at very high (~30%) compression. In addition, Moon adds, smaller substances such as biomolecules or nanoparticles can follow the water channel to form aligned 1-dimensional nanostructures. “Smaller is better. Less is more. We’ve found that the wrinkle-to-fold transition takes place more easily when the following factors become smaller: compression level, skin thickness, droplet volume, size of the sample surface, and static contact angles of droplets.”Based on their findings, the authors stated that their approach could lead to new ways of fabricating functional materials. “Our key finding is that one can change wrinkles into localized folds by simply exploiting the capillary forces of water on wrinkled surfaces under very small strain of about 1% in compression,” Nagashima tells Phys.org. “Recent studies reported in the literature have demonstrated that such wrinkle-to-fold transitions can help develop systems that dynamically change their properties according to the surface morphology. However, inducing the transition in the absence of water is difficult to achieve in practice because, in general, large compression needs to be applied to the skin-substrate system, which hinders wider applications. Our study reveals that even 1% of compression, which is the critical level for creating wrinkles in our case, is large enough to trigger the transition to folds locally when water is present.” Nagashima notes that while the compression level required to induce the transition might differ according to the skin-film system used, only a small compression level would be necessary in combination with water. Observation of the phase transition of liquid crystal defects for the first time Fig. 3. Tunable DNA nanowires. (A) Bright- and dark-field optical microscope images of DNA nanowires created by the capillarity-induced wrinkle-to-fold transition. After evaporation of the droplet, the strain was adjusted to see the structure inside the folds. (B) Confocal microscope images of an array of DNA nanowires extending from the boundary to the locations indicated by the yellow triangles. (C) AFM images of DNA nanowires obtained using wrinkles prepared with various ε (t = 10 min). After the folds were formed, the strain was adjusted to ε ≈ 0.00. The line profiles of the nanowires indicated by the green dotted lines are shown in the images. (D) Height of the nanowires as a function of t (ε ≈ −0.03). (E) Changes in shape of a DNA nanowire from straight to wrinkled with an increase in tensile strain. (F) The wavelength (black symbols) and amplitude (orange symbols) of the wrinkled DNA nanowires as a function of applied tensile strain. (G and H) The line profiles of the DNA nanowire and the skin surface before and after application of the tensile strain (i.e., ε ≈ −0.02 and 0.05, respectively). The color of the profiles corresponds to that of the dotted lines indicated in the AFM images shown in E. (Scale bars: A and B, 10 μm; C, 2 μm; and E, 1 μm.). Credit: Nagashimaa S, Haa HD, Kima DH, Košmrljb A, Stone HA, Moon M-W (2017) Spontaneous formation of aligned DNA nanowires by capillarity-induced skin folding. Proc Natl Acad Sci USA 114:24 6233-6237. , Science (Phys.org)—Nanowires fashioned from DNA (deoxyribonucleic acid)—one of several type of molecular nanowires incorporating repeating molecular units—are exactly that: Geometrically wire-like DNA-based nanostructures defined variously as having a 1~10 nm (10−9 m) diameter or a length-to-diameter ratio >1000. While nanowires can be made from several organic and inorganic materials, DNA nanowires have been shown to provide a range of valuable applications in programmed self-assembly1,2 of functional materials—including metallic and semiconductor nanowires for use in electronic devices—as well as biological, medical, and genetic analysis applications3,4,5. That being said, DNA nanowire adoption has been limited due to historical limitations in the ability to control their structural parameters—specifically, size, geometry and alignment. Recently, however, scientists at Korea Institute of Science and Technology and Princeton University leveraged the capillary forces of water containing DNA molecules to demonstrate size-controllable straight or undulated aligned DNA nanowires that were spontaneously formed by water entering wrinkled channels of a compressed thin skin on a soft substrate, which subsequently induced a wrinkle-to-fold transition. © 2017 Phys.org This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
Chinese writer Mo Yan, who has won this year’s Nobel Prize for literature, is relatively unknown to Indian readers and book shops in the capital were Friday scrambling to put his books on their shelves.Books by Mo are not easy to come by, complained a reader.‘I wanted to know about Mo Yan when I heard that he had received the Nobel Prize for literature, but none of the book shops in south Delhi had any of his books,’ Soma Basu, a resident of Greater Kailash, said. Also Read – ‘Playing Jojo was emotionally exhausting’But book shops said they were doing their best to comply with the sudden demand for Mo, who plots his narratives around the socio-historical perspectives of China on massive colourful canvases.Midland, a reputed book retail chain in the capital, is getting copies of Mo’s Garlic Ballads from its publisher, Arcade, in the US.‘Not many people have read Mo Yan. Till this week, he was completely unknown. But since Thursday, readers have been walking into my shop for his books,’ M A Baig, the founder of the chain said. Also Read – Leslie doing new comedy special with NetflixThe bookstore does brisk business in the novels of popular Chinese writer Gao Xinjiang – the Chinese emigre to France who in 2000 was awarded the Nobel Prize for literature.‘Three of Gao’s books, Soul Mountain, One Man’s Bible and Buying a Fishing Rod sell fairly well… Now Mo’s books will find takers,’ Baig said.Bahrisons in the capital’s Khan Market expects to receive its first consignment of Mo’s books soon.‘We don’t have any books by Mo Yan but his rival Haruki Murakami, who was in the race for the Nobel Prize, sells very well in the country. Mo Yan is not popular but the Nobel Prize has changed his popularity status in India… By Saturday we hope to get fresh stocks from distributors,’ a spokesperson for Bahrisons said. Crossword, one of the biggest book chains in the capital, does not have Mo Yan on its shelves either.‘Not now… Later,’ said a spokesperson for the Crossword Bookstore at Rajouri Garden in the capital.For online readers, Mo’s Change and Red Sorghum are available on Flipkart and Infibeam.Foreign publishing companies in India are not yet ready to meet any sudden interest in Mo Yan’s novels.A spokesperson for Pan Macmillan said: ‘The publishing house has not yet published any of Nobel Laureate Mo Yan’s books.’‘He is still unknown in India and around the world. But now that he has won a Nobel Prize, it will draw readers to his books,” the spokesperson for Pan Macmillan India said.The acclaimed Red Sorghum: A Novel on China, spanning the saga of three generations of a family in the 1930s, which was made into an Oscar-winning movie, has been published in translation by Penguin US. ‘The book is available in India,’ the publisher said. The book sells because of its popularity on screen.‘The Nobel Prize is a political call these days and the idea of giving one to a Chinese author could be a politically fraught decision in a year which saw the famous Chinese dissident Chen Guang Chen… seek refuge in the American Embassy; [Mo’s] books bring out the other side of China,” senior communications executive Manish Singh, an avid reader of the classics, told IANS.According to reports from China, Mo’s latest and most popular “Frog” about China’s “one child birth control” has sold more than 200,000 copies since it was published in 2009. It is yet to reach the Indian audience in translation.
English clarinet player Acker Bilk, who beat the Beatles and other British rockers to the top of the US music charts with the instrumental ‘Stranger on the Shore,’ has died at the age of 85. Manager Sutton said Bilk died on Sunday at a hospital in Bath, England. The cause of death was not announced.Born Bernard Stanley Bilk in 1929 in the southwestern English county of Somerset, Bilk adopted the name Acker from a local slang term for friend.He learned the clarinet as a bored army conscript, stationed in Egypt after World War II, and became one of the stars of Britain’s 1950s ‘trad jazz’ scene.
Doordarshan National celebrated December 25 as the birth anniversary of two exemplary personalities of the nation- Atal Bihari Vajpayee and Madan Mohan Malviya. Following the Prime Minister’s declaration of observing December 25 as ‘Good Governance Day’, the public broadcaster had lined up several special documentaries for telecast.Geet Naya Gata Hoon a documentary on Shri Atal Bihari Vajpayee; the statesman, parliamentarian of four decades, Ex PM of India, great orator, poet, literateur and key person in achieving political milestones nationally and internationally. Also Read – ‘Playing Jojo was emotionally exhausting’He was at the head of successfully executing the Pokhran II Nucleur test, initiating the Sadbhavna yatra from India to Pakistan, starting the Quadruple Road Scheme amongst many other achievements. With the backdrop of his poetry and songs, the film was telecasted on December 25 , at 11 am and repeated at 10:30 pm.Another documentary dedicated to this outstanding personality, octogenarian, and a source of inspiration for all the countrymen – Rashtriyaneta Rajneta, was aired at 9:30 am . Also Read – Leslie doing new comedy special with NetflixAt 9 am a documentary, Swapna Sakaar: documentary on Mahamana Pt. Madan Mohan Malviya was telecasted to pay a tribute to the magnificent personality highlighting his political, social and educational career. An Indian educationist and politician notable for his role in the Indian independence movement and his espousal of Hindu nationalism; he was given the title of ‘Mahamana’. He was the President of the Indian National Congress on two occasions (1909 and 1918).
This season, immerse in mesmerising regional handloom weaves like Maheshwari, Kota, Ikats and fine Bandhini along with block printed textiles in Ajrakh, Bagru and Dabu styles. Splendid garments, fabrics and furnishings embellished with regional embroideries will be available in Ari, Sindhi, Lambani, Sozni and Applique. Organic cottons and naturally dyed children’s clothing with eco herbal essential oils and designer combs made out of neem will showcase versatility of natural materials. Also Read – ‘Playing Jojo was emotionally exhausting’Traditional leather footwear along with tribal, bead and thread based jewellery that shall surely leave you asking for more. Pottery, wood carving, cotton dhurries will feature along with environment-friendly handmade Moonj baskets along with Candles, Sikki and Paper Mache decoratives.Regional painting forms like Madhubani, Kalamkari and Tanjore shall further leave you spellbound. Ruaab-sewa brings you craft products from Ethiopia, for the very first time. Hand-spun cotton handlooms, carved leather bags and purses, decorative clay items and painted pottery tea-sets along with jewellery made from indigenous Ethiopian wood and a selection of local Ethiopian silver jewellery will be showcased. It will be a cross cultural exchange of traditions and discover the hospitality of their ritual ‘Coffee Ceremony’ using their famous “Bunna” coffee. Also Read – Leslie doing new comedy special with NetflixOne of the many unique Indian crafts represented, will be Rogan Paintings by Md. Jabbar A. Khatri from Kutch, Gujarat. The rare technique is only practiced by 10 people in the village of Nirona in Kutch, and the importance for giving these artists a strong market platform was evident in Prime Minister, Narendra Modi, choosing a Rogan Painting to be India’s gift to US President, Barrack Obama.Dastkar, a registered NGO working with crafts and craftspeople for over three decades, strongly believes in crafts as a catalytic tool for social and economic empowerment and earning. It aims to break the barriers that separate craftspeople from mainstream urban markets, reviving and revitalizing both the craft and the community.Where: The Nature Bazaar Avenue, Kisan Haat, near Chhatarpur metro stationWhen: February 12 – Feb 23 Timings: 11:00 a.m. – 7:00 p.m. Entry: Rs. 20
A 16-year-old girl from USA, who stays in Gurgaon with her mother, alleged that she was raped by a youth of African origin whom she reportedly met over a social networking site around six months ago.The accused has been identified as David (22) from his Facebook account. He is presently on a run and the girl could not provide any more details to the police beyond what is there in the accused youth’s Facebook account. A case has been registered under the Protection of Children from Sexual Offences (POCSO) Act and relevant sections of IPC. The police are looking for David despite being entirely clueless about his whereabouts. Also Read – Company director arrested for swindling Rs 345 croreThe girl belongs to Texas in USA. She lives at an apartment in Gurgaon sector 47 with her mother, who works as an executive in a multinational company. The accused and the girl exchanged their contact details over Facebook around six months ago, after which they met each other thrice. On March 16, the accused took the girl to a hotel in Gurgaon sector 38, where he allegedly sexually assaulted her, said a police official.After the incident, the girl went to a hospital in Delhi on her own and got her medical examination done. Being confirmed about sexual assault, she narrated her ordeal to her mother, who later called up the police control room and reported to the police.
Santiniketan (West Bengal): Prime Minister Narendra Modi and his Bangladeshi counterpart Sheikh Hasina inaugurated the Bangladesh Bhavan here on Friday to symbolically highlight the warm bilateral cultural ties between the two countries. The inauguration of Bangladesh Bhavan inside the Vishwa Bharti University complex took place in the presence of West Bengal Chief Minister Mamata Banerjee.The Bangladesh Bhavan features a museum that showcases renowned poet Rabindranath Tagore’s association with that country, the Liberation War of Bangladesh and Indo-Bangla relations. Also Read – Heavy rain hits traffic, flightsIt has been built at a cost of Rs. 25 crores, which was provided by the Bangladesh government.A fund of Rs. 10 crores would be given to help maintain the museum premises.Reportedly, a Memorandum of Understanding (MoU) will also be signed between Vishwa Bharati University and the Secondary and Higher Secondary Division of the Bangladesh education ministry.Prime Minister Hasina, who is on a two-day visit to India, on the invitation of Prime Minister Modi, was received by Banerjee.As per reports, both Prime Ministers will hold a bilateral meeting.Prime Minister Hasina will return to Bangladesh on Saturday night.
Kolkata: Chief Minister prayed for world peace while inaugurating the Rath Yatra festival organised by the International Society for Krishna Consciousness (ISKCON) in Kolkata on Saturday.She pulled the rope and marked the beginning of the seven-day festival. “Religion is personal but people from every faith take part in the festival of peace and harmony,” she maintained.Thousands of people gathered at the Radha Govinda temple on Albert Road to pull the rope which is considered to be extremely auspicious on Rath Yatra. Indranil Sen, Minister of State for Information and Cultural Affairs, Rajeev Kumar, Kolkata Police Commissioner, Moon Moon Sen and Subrata Bakshi, party MPs and Debashis Kumar, Member, Mayor-in-Council (Parks and Squares) were present at the inaugural function. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedThe Rath will reach maidan where a temporary mashir bari (aunt’s house) has been set up via Sarat Bose Road, Hazra Road, Asutosh Mookerjee Road and Jawaharlal Nehru Road. There will be week-long celebrations at Maidan where there will be religious discourses on Srimad Bhagavatam, kirtans and bhajans in which devotees of the ISKCON who have come from all over the world will take part.ISKCON has been celebrating the Rath Yatra in Kolkata for the past 46 years. It was started on July 12, 1972, in which Bhagavan Prabhupada was present along with his Western devotees like Jaipataha Swami and Achyutananda Swami. While Prabhupada sang Hare Krishna Mahamantra, Jaipataka Swami played the cymbals and Achyutananda Swami played the drums. It was the first time when Kolkatans saw Western devotees dancing and chanting Hare Krishna. Also Read – Naihati: 10 councillors return to TMC from BJPThe Rath Yatra festival was observed with great enthusiasm at Mayapur. Lakhs of people coming from different caste, creed and religion pulled the rope and enjoyed prasadam served by the ISKCON monks.Rath Yatra festival was also observed at Mahesh in Hooghly district where thousands of devotees pulled the rope. There is a fair organised along GT Road where elaborate police arrangements have been made for smooth manoeuvre of the Rath.In Balaram mandir, a unit of Ramakrishna Mission, hundreds of devotees pulled the rope. A special puja was also observed. Swami Vagishanandaji, one of the presidents of Ramakrishna Math and Mission pulled the rope to mark the beginning of the festival. It may be recalled the Sri Ramakrishna had pulled the rope of the chariot along with his devotees over a century ago at Balaram Basu’s house which is now known as Balaram Mandir.