Harnessing Protonated 2,2′-Bipyridinium Salts as Powerful Brønsted Acid Catalysts in Organic Reactions

It is the first time that the readily available protonated 2,2′-bipyridinium salts are used as Brønsted acid catalysts to accelerate a series of organic transformations that included the hydration of aromatic alkynes, etherification of alcohols, cyclotrimerization of aliphatic aldehydes, Ritter reaction, Mannich reaction, Biginelli reaction, preparation of substituted alkenes from alcohols, synthesis of spirooxindole, bisindolylmethane, and noncyclized tetraketone with good to excellent yields. These results strongly suggest that there exists enormous potentiality in the development of the protonated 2,2′-bipyridinium catalytic system

DataSheet1_Revealing Critical Characteristics of Mobility Patterns in New York City During the Onset of COVID-19 Pandemic.docx

New York has become one of the worst-affected COVID-19 hotspots and a pandemic epicenter due to the ongoing crisis. This paper identifies the impact of the pandemic and the effectiveness of government policies on human mobility by analyzing multiple datasets available at both macro and micro levels for New York City. Using data sources related to population density, aggregated population mobility, public rail transit use, vehicle use, hotspot and non-hotspot movement patterns, and human activity agglomeration, we analyzed the inter-borough and intra-borough movement for New York City by aggregating the data at the borough level. We also assessed the internodal population movement amongst hotspot and non-hotspot points of interest for the month of March and April 2020. Results indicate a drop of about 80% in people’s mobility in the city, beginning in mid-March. The movement to and from Manhattan showed the most disruption for both public transit and road traffic. The city saw its first case on March 1, 2020, but disruptions in mobility can be seen only after the second week of March when the shelter in place orders was put in effect. Owing to people working from home and adhering to stay-at-home orders, Manhattan saw the largest disruption to both inter- and intra-borough movement. But the risk of spread of infection in Manhattan turned out to be high because of higher hotspot-linked movements. The stay-at-home restrictions also led to an increased population density in Brooklyn and Queens as people were not commuting to Manhattan. Insights obtained from this study would help policymakers better understand human behavior and their response to the news and governmental policies.</p

Physical Unclonable Functions Based on Photothermal Effect of Gold Nanoparticles

Physical unclonable functions (PUFs) based on uncontrollable fabrication randomness are promising candidates for anticounterfeiting applications. Currently, the most popular optical PUFs are generally constructed from the scattering, fluorescent, or Raman phenomenon of nanomaterials. To further improve the security level of optical PUFs, advanced functions transparent to the above optical phenomenon have always been perused by researchers. Herein, we propose a new type of PUF based on the photothermal effect of gold nanoparticles, which shows negligible scattering, fluorescent, or Raman responses. The gold nanoparticles are randomly dispersed onto the surface of fused silica, which can enhance the photothermal effect and facilitate high contrast responses. By tuning the areal density of the gold nanoparticles, the optimized encoding capacity (2319) and the total authentication error probability (3.6428 × 10–24) are achieved from our PUF due to excellent bit uniformity (0.519) and inter Hamming distances (0.503). Moreover, the intra-Hamming distance (0.044) indicates the desired reliability. This advanced PUF with invisible features and high contrast responses provides a promising opportunity to implement authentication and identification with high security

<i>Seeing the Forest for the Trees</i> Sequel II: An Exploratory Bibliometric Analysis of the Chinese Environmental and Resource Sociology/Social Science Literature

Research on societal–environmental interactions has gained increasing currency in China during the past several decades. Unlike relevant fields of study in the United States, environmentally oriented sociological research in China has not evolved into two separate subdisciplines—environmental sociology (ES) and natural resource sociology (NRS). However, it is not clear how Chinese sociological/social science research communities associated with environmental and natural resource problems are linked with each other. We conducted an exploratory bibliometric analysis to examine scholarly networks in selected Chinese literature. The results reveal the coexistence of two distinct subfields representing the sociological and resource/environmental science traditions in environmental and natural resource social sciences. Closer collaborations across research lineages will not only contribute to the development of integrative environmental and resource sociology/social science in China, but furnish meaningful implications for the ES–NRS dialogue in the United States and global contexts as well.</p

Additional file 1 of Mechanism of exosomal miR-155 derived from bone marrow mesenchymal stem cells on stemness maintenance and drug resistance in myeloma cells

Additional file 1. BMSC-derived exosomes carrying miR-155 inhibited apoptosis, promoted cell division, and upregulated the expression of protein associated with stemness maintenance, Hedgehog signaling, and drug resistance

Tunable Key-Size Physical Unclonable Functions Based on Phase Segregation in Mixed Halide Perovskites

Optical physical unclonable functions (PUFs) have been considered as an effective tool for anti-counterfeiting owing to the uncontrollable manufacturing process and excellent resistance to machine-learning attacks. However, most optical PUFs exhibit fixed challenge-response pairs and static encoding structures after they are manufactured, which significantly impedes the actual development. Herein, we propose a tunable key-size PUF based on reversible phase segregation in mixed halide perovskites with uncontrollable Br/I ratios under variable power densities. The basic performance of encryption keys of low and high power density was evaluated and indicated a high degree of uniformity, uniqueness, and readout repeatability. Merging the binary keys of low and high power density, tunable key-size PUF is realized with higher security. The proposed tunable key-size PUF offers new insights into the development of dynamic-structure PUFs and demonstrates a novel scheme for achieving higher security of anti-counterfeiting and authentication

Additional file 8: of Transcriptomics reveals the molecular processes of light-induced rapid darkening of the non-obligate cave dweller Oreolalax rhodostigmatus (Megophryidae, Anura) and their genetic basis of pigmentation strategy

Table S6. Information of unigenes used in analysis and figures. (XLSX 538 kb

Additional file 1: of Transcriptomics reveals the molecular processes of light-induced rapid darkening of the non-obligate cave dweller Oreolalax rhodostigmatus (Megophryidae, Anura) and their genetic basis of pigmentation strategy

Table S1. Summary of sequencing quality. (XLSX 9 kb

Additional file 6: of Transcriptomics reveals the molecular processes of light-induced rapid darkening of the non-obligate cave dweller Oreolalax rhodostigmatus (Megophryidae, Anura) and their genetic basis of pigmentation strategy

Table S5. Summary of enrichment based on stricter light-inducible genes (213). (XLSX 32 kb

Additional file 2: of Transcriptomics reveals the molecular processes of light-induced rapid darkening of the non-obligate cave dweller Oreolalax rhodostigmatus (Megophryidae, Anura) and their genetic basis of pigmentation strategy

Figure S1. Length distribution of transcripts and unigenes. (PDF 4 kb