Yb³⁺-Doped Two-Dimensional Upconverting Tb-MOF Nanosheets with Luminescence Sensing Properties

In this article, we synthesized a Yb3+-doped two-dimensional (2-D) upconverting Tb metal–organic framework (Tb-MOF) (hereinafter referred to as Tb-UCMOF) by a one-step solvothermal method. The synthesized Tb-UCMOF is composed of stacks of 2-D nanosheets with an average width distributed between 250 and 300 nm, and these nanosheets can be exfoliated by a simple liquid ultrasound method. The structural characteristics of this flaky particle accumulation are confirmed by the type IV adsorption–desorption isotherm with a H3-type adsorption hysteresis loop, and the Brunauer–Emmett–Teller surface of Tb-UCMOF is 143.9257 m2·g–1. Tb-UCMOF has characteristic emissions of Tb3+ which are located at 490, 545, 585, and 621 nm under 980 nm excitation. The upconverting luminescence mechanism is attributed to that Yb3+ absorbs multiple photons and transfers the energy to Tb3+, causing its 4f electrons to jump to the excited state, and then the upconverting emissions are obtained when electrons return to the ground state. Since the Tb-UCMOF nanosheets have high dispersibility and an obvious upconverting luminescent signal, we explored their luminescence sensing properties. The luminescence intensity is found to gradually decrease with the addition of Cu2+, the linear range of Cu2+ sensing is 0–1.4 μM, and the detection limit is 0.16 μM. This rapid, highly selective, and sensitive Cu2+ sensing indicates that 2-D upconverting MOF nanosheets have great application prospects in luminescence sensing and also promote the research of 2-D upconverting MOFs with specific recognition for the application of biological and environmental luminescent sensors

sj-tif-1-uix-10.1177_01617346221085184 – Supplemental material for The Spectrum-Beamformer for Conventional B-Mode Ultrasound Imaging System: Principle, Validation, and Robustness

Supplemental material, sj-tif-1-uix-10.1177_01617346221085184 for The Spectrum-Beamformer for Conventional B-Mode Ultrasound Imaging System: Principle, Validation, and Robustness by Chen Jiang, Chengcheng Liu, Yiqiang Zhan and Dean Ta in Ultrasonic Imaging</p

A new fast response colorimetric and fluorescent probe for the detection of bisulfite and its application on test strips

A new carbazole-based colorimetric and fluorescent probe CBB for the detection of bisulfite (HSO3−) has been developed via nucleophilic addition reaction. Probe CBB can detect HSO3− with excellent sensing properties including high selectivity and sensitivity, fast response (5 s). More importantly, probe CBB system not only can be applied to monitor HSO3− in environment with excellent solid properties based on test strips but also can be used for the detection of HSO3− in real-water samples with satisfactory results.</p

Kekule.js: An Open Source JavaScript Chemoinformatics Toolkit

Kekule.js is an open-source, object-oriented JavaScript toolkit for chemoinformatics. It provides methods for many common tasks in molecular informatics, including chemical data input/output (I/O), two- and three-dimensional (2D/3D) rendering of chemical structure, stereo identification, ring perception, structure comparison, and substructure search. Encapsulated widgets to display and edit chemical structures directly in web context are also supplied. Developed with web standards, the toolkit is ideal for building chemoinformatics applications over the Internet. Moreover, it is highly platform-independent and can also be used in desktop or mobile environments. Some initial applications, such as plugins for inputting chemical structures on the web and uses in chemistry education, have been developed based on the toolkit

Characterization of Morphology and Structure of Wax Crystals in Waxy Crude Oils by Terahertz Time-Domain Spectroscopy

The content, morphology, and structure of precipitated wax crystals are major factors affecting crude oil rheology. In this paper, model oils obtained by dissolving a realistic mixture of long-chain <i>n</i>-octacosane in diesel fuels were studied using terahertz time-domain spectroscopy (THz-TDS) and microscopy to gain insight into clusters composed of asphaltene and wax with increasing wax content. The fractal dimension was used for quantitative characterization of the morphology and structure of clusters in the model oils. From the measured absorption and extinction coefficients in the THz region, dynamic processes of the clusters in the model oils were analyzed and identified. The extinction coefficient in the THz region strongly depended on the dispersed and aggregated states of the asphaltene and wax crystals. These observations suggest that the aggregation state of the particles in model oils can be monitored with THz-TDS. In the future, THz-TDS technology may be used to effectively analyze particle dispersion or the aggregation state in crude oil and may thus be useful for rapid assessment of the effect of pour-point depressant on wax crystal aggregates

Spatial distribution map of SST in the NSCS during the passage of Merbok.

Spatial distribution map of SST in the NSCS during the passage of Merbok.</p

Cyber security monitoring for IHEP data centers

In recent years, along with the rapid development of large scientific facilities and e-science worldwide, various cyber security threats have becoming a noticeable challenge in many data centers for scientific research, such as DDoS attack, ransomware, crypto-currency mining, data leak, etc. Intrusion and abnormality detection by collecting and analyzing security data is an important measure for enhancing the sensitivity of security status perception, level of security protection, and agility of security incident response. However, as the scale of data center growing, it's difficult to use a single security box to process the large volume of various data generated by network traffic, device and host logs, threat intelligence, and so on. In high energy physics (HEP) community, people are trying to establish a security operation center (SOC) for handle this problem. We are also trying to build a cyber security monitoring and analysis framework at Institute of High Energy Physics (IHEP), Chinese Academy of Sciences. At IHEP, we have four data centers, located in three different cities in China, the largest one has 4x10 Gbps IPv4 and IPv6 dual-stacked internet connection, and 2x80 Gbps inner data center network. It's really a challenge for us to handle the security related data generated by such a set of information assets. In this framework, Malware Information Sharing Platform (MISP) is deployed for threat intelligence exchanging with collaborated HEP institutes and universities. Network traffic is collected from switches and firewalls flows to a Zeek instance for traffic analysis. All the security data like Zeek logs, hosts/web logs, security device logs, along with vulnerability scanning results and assets detection results, etc., are are collected by Flume/Logstash/Syslog to a data pipeline named Kafka cluster. In this cluster, there are some Spark jobs running for stream processing, which are aimed at rapid intrusion and abnormality detection as well as data correlation and enrichment. Then all the processed data are written to Elasticsearch, MySQL and InfluxDB, and then visualized by Kibana and Grafana. Moreover, we also deployed a commercial SOC product for cross-checking, and we imported the threat intelligence data from the cloud of the product provider

Peptide-Conjugated PAMAM for Targeted Doxorubicin Delivery to Transferrin Receptor Overexpressed Tumors

The purpose of this work was to evaluate the potential of HAIYPRH (T7) peptide as a ligand for constructing tumor-targeting drug delivery systems. T7 could target to transferrin-receptor (TfR) through a cavity on the surface of TfR and then transport into cells via endocytosis with the help of transferrin (Tf). In this study, T7-conjugated poly(ethylene glycol) (PEG)-modified polyamidoamine dendrimer (PAMAM) (PAMAM-PEG-T7) was successfully synthesized and further loaded with doxorubicin (DOX), formulating PAMAM-PEG-T7/DOX nanoparticles (NPs). In vitro, almost 100% of DOX was released during 2 h in pH 5.5, while only 55% of DOX was released over 48 h in pH 7.4. The cellular uptake of DOX could be significantly enhanced when treated with T7-modified NPs in the presence of Tf. Also, the in vitro antitumor effect was enhanced markedly. The IC50 of PAMAM-PEG-T7/DOX NPs with Tf was 231.5 nM, while that of NPs without Tf was 676.7 nM. T7-modified NPs could significantly enhance DOX accumulation in the tumor by approximately 1.7-fold compared to that of unmodified ones and by approximately 5.3-fold compared to that of free DOX. For in vivo antitumor studies, tumor growth of mice treated with PAMAM-PEG-T7/DOX NPs was significantly inhibited compared to that of mice treated with PAMAM-PEG/DOX NPs and saline. The study provides evidence that PAMAM-PEG-T7 can be applied as a potential tumor-targeting drug delivery system. T7 may be a promising ligand for targeted drug delivery to the tumor

Map of the study area and track of tropical storm merbok (the black box represents the study area; the colors represent the maximum sustained wind; the plus signs represent the sampling stations).

The location information: S56 (114.59°E, 22.47°N), S57 (114.67°E, 22.33°N), S59 (114.85°E, 22.17°N), S61 (115.00°E, 22.00°N), S63 (115.13°E, 21.87°N), S65 (115.25°E, 21.75°N) and S67 (115.37°E, 21.63°N).</p

Unveiling the Distinct Mechanisms by which Disease-Causing Mutations in the Kelch Domain of KLHL3 Disrupt the Interaction with the Acidic Motif of WNK4 through Molecular Dynamics Simulation

Kelch-like 3 (KLHL3) is a substrate adaptor of an E3 ubiquitin ligase complex that regulates the degradation of its substrates, including with-no-lysine [K] kinase 4 (WNK4). Mutations in KLHL3 are associated with pseudohypoaldosteronism type II (PHAII), a hereditary form of hypertension. Many PHAII-causing mutations are located in the Kelch domain of KLHL3 that binds with WNK4; however, detailed mechanisms by which these mutations disrupt the binding are not well-understood. In the present study we use molecular dynamics simulations and Western blot analyses to examine the effects of these mutations on the interaction between the Kelch domain of KLHL3 and the acidic motif (AM) of WNK4. The simulation results correlated well with those from Western blot analyses with the exception of the L387P mutation, which led to deregulation of AM degradation by KLHL3 but not recapitulated by simulations. On the basis of the simulation results, a mutation on the binding surface of the Kelch domain affected the Kelch-AM interaction through two major mechanisms: altering the electrostatic potential of the AM binding site and disrupting the Kelch-AM hydrogen bonds. The mutations buried inside the Kelch domain were predicted by our simulations to have no or modest effects on the Kelch-AM interaction. Buried mutations R384Q and S410L disrupted intramolecular hydrogen bonds within the Kelch domain and affected the Kelch-AM interaction indirectly. No significant effect of buried mutation A340V or A494T on the AM degradation or Kelch-AM interaction was observed, implying these mutations may disrupt mechanisms other than Kelch-AM interaction