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"Cheng, Wei"
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Identification of existing pharmaceuticals and herbal medicines as inhibitors of SARS-CoV-2 infection
The outbreak of COVID-19 caused by SARS-CoV-2 has resulted in more than 50 million confirmed cases and over 1 million deaths worldwide as of November 2020. Currently, there are no effective antivirals approved by the Food and Drug Administration to contain this pandemic except the antiviral agent remdesivir. In addition, the trimeric spike protein on the viral surface is highly glycosylated and almost 200,000 variants with mutations at more than 1,000 positions in its 1,273 amino acid sequence were reported, posing a major challenge in the development of antibodies and vaccines. It is therefore urgently needed to have alternative and timely treatments for the disease. In this study, we used a cell-based infection assay to screen more than 3,000 agents used in humans and animals, including 2,855 small molecules and 190 traditional herbal medicines, and identified 15 active small molecules in concentrations ranging from 0.1 nM to 50 μM. Two enzymatic assays, along with molecular modeling, were then developed to confirm those targeting the virus 3CL protease and the RNA-dependent RNA polymerase. Several water extracts of herbal medicines were active in the cell-based assay and could be further developed as plant-derived anti–SARS-CoV-2 agents. Some of the active compounds identified in the screen were further tested in vivo, and it was found that mefloquine, nelfinavir, and extracts of Ganoderma lucidum (RF3), Perilla frutescens, and Mentha haplocalyx were effective in a challenge study using hamsters as disease model.
Journal Article
Hierarchical and programmable one-pot synthesis of oligosaccharides
The programmable one-pot oligosaccharide synthesis method was designed to enable the rapid synthesis of a large number of oligosaccharides, using the software Optimer to search Building BLocks (BBLs) with defined relative reactivity values (RRVs) to be used sequentially in the one-pot reaction. However, there were only about 50 BBLs with measured RRVs in the original library and the method could only synthesize small oligosaccharides due to the RRV ordering requirement. Here, we increase the library to include 154 validated BBLs and more than 50,000 virtual BBLs with predicted RRVs by machine learning. We also develop the software Auto-CHO to accommodate more data handling and support hierarchical one-pot synthesis using fragments as BBLs generated by the one-pot synthesis. This advanced programmable one-pot method provides potential synthetic solutions for complex glycans with four successful examples demonstrated in this work.
The software Optimer has aided the programmable one-pot oligosaccharide synthesis with a library of 50 Building BLocks (BBLs). Here, the authors expanded Optimer's validated and virtual libraries of BBLs and developed Auto-CHO, a software which allows the one-pot programmable synthesis of more complex glycans.
Journal Article
الضمان الاجتماعي والحد من الفقر : التجربة الصينية
هذا الكتاب يلخص التجربة الصينية في الضمان الاجتماعي والحد من الفقر مستعرضا التحديات التي واجهتها الصين حتى صارت نموذجا للبلدان الساعية لتحقيق نتائج إيجابية في مكافحة الفقر والضمان الاجتماعي، إذ يفند التجربة الصينية من عدة جوانب، ويجذب الانتباه إلى المواضع التي تنتظر التحديث والتطوير. كما يناقش القضايا النظرية الأساسية في مجالات الرعاية والتأمين الاجتماعي والمساعدة الاجتماعية ويستعرض قضية التنسيق والتكامل بين الضمان الاجتماعي والحد من الفقر، كما يجري تحليلات وتوقعات للقضايا والتحديات والتطورات في المجالات ذات الصلة مستندا إلى البيانات والمعلومات الصادرة عن الجهات الرسمية الصينية.
Book
Zero-bias mid-infrared graphene photodetectors with bulk photoresponse and calibration-free polarization detection
Bulk photovoltaic effect (BPVE), featuring polarization-dependent uniform photoresponse at zero external bias, holds potential for exceeding the Shockley-Queisser limit in the efficiency of existing opto-electronic devices. However, the implementation of BPVE has been limited to the naturally existing materials with broken inversion symmetry, such as ferroelectrics, which suffer low efficiencies. Here, we propose metasurface-mediated graphene photodetectors with cascaded polarization-sensitive photoresponse under uniform illumination, mimicking an artificial BPVE. With the assistance of non-centrosymmetric metallic nanoantennas, the hot photocarriers in graphene gain a momentum upon their excitation and form a shift current which is nonlocal and directional. Thereafter, we demonstrate zero-bias uncooled mid-infrared photodetectors with three orders higher responsivity than conventional BPVE and a noise equivalent power of 0.12 nW Hz
−1/2
. Besides, we observe a vectorial photoresponse which allows us to detect the polarization angle of incident light with a single device. Our strategy opens up alternative possibilities for scalable, low-cost, multifunctional infrared photodetectors.
Here, graphene-based plasmonic metamaterials are used to generate an artificial bulk photovoltaic effect, enabling the realization of mid-infrared photodetectors with enhanced responsivity and calibration-free polarization detection at room temperature.
Journal Article
غبار تحت الشمس : قصص قصيرة
يعرض الكتاب بين دفتيه قصصا قصيرة لعادات الأقليات الصينية، وسلوكيات العائلات في المناسبات الدينية والاحتفالات الأخرى المختلفة، وتتباين فيها الشخصيات والزمان والمكان، لتضع القارئ أمام رسم أدبي يشرح حياة الأقليات الصينية المليئة بالتفاصيل والمفارقات. الكتاب من تأليف: يه شنغ فو، وترجمة عن الصينية.
Book
Structured thermal surface for radiative camouflage
Thermal camouflage has been successful in the conductive regime, where thermal metamaterials embedded in a conductive system can manipulate heat conduction inside the bulk. Most reported approaches are background-dependent and not applicable to radiative heat emitted from the surface of the system. A coating with engineered emissivity is one option for radiative camouflage, but only when the background has uniform temperature. Here, we propose a strategy for radiative camouflage of external objects on a given background using a structured thermal surface. The device is non-invasive and restores arbitrary background temperature distributions on its top. For many practical candidates of the background material with similar emissivity as the device, the object can thereby be radiatively concealed without a priori knowledge of the host conductivity and temperature. We expect this strategy to meet the demands of anti-detection and thermal radiation manipulation in complex unknown environments and to inspire developments in phononic and photonic thermotronics.
Thermal camouflaging techniques typically use bulky structures and require a well-defined and unchanging background. Here, the authors propose a strategy for thermal camouflage using a structured thermal surface, independent of the background material for many practical situations.
Journal Article
الحصن المحاصر
في هذا الكتاب الحصن المحاصر للمؤلف تشيان جونغ شو يتحدث ويتناول المؤلف عن حصار المجتمع الصيني وبالأخص طبقة المثقفين في تلك الفترة داخل أنفسها قبل أن يكون حصارا بأسوار الاحتلال وكما تناول غلبة الصراع من النزاع الداخلي والتزاحم في جو من المكائد بدلا من التركيز في مواجهة العدو الياباني المشترك في هذا الوقت.
BOOK
High-purity orbital angular momentum states from a visible metasurface laser
Orbital angular momentum (OAM) from lasers holds promise for compact, at-source solutions for applications ranging from imaging to communications. However, conjugate symmetry between circular spin and opposite helicity OAM states (±ℓ) from conventional spin–orbit approaches has meant that complete control of light’s angular momentum from lasers has remained elusive. Here, we report a metasurface-enhanced laser that overcomes this limitation. We demonstrate new high-purity OAM states with quantum numbers reaching ℓ = 100 and non-symmetric vector vortex beams that lase simultaneously on independent OAM states as much as Δℓ = 90 apart, an extreme violation of previous symmetric spin–orbit lasing devices. Our laser conveniently outputs in the visible, producing new OAM states of light as well as all previously reported OAM modes from lasers, offering a compact and power-scalable source that harnesses intracavity structured matter for the creation of arbitrary chiral states of structured light.A metasurface laser generates orbital angular momentum states with quantum numbers reaching ℓ = 100. Simultaneous output vortex beams, with Δℓ as great as 90, are demonstrated in the visible regime.
Journal Article