Enhancing Received Signal Strength-Based Localization through Coverage Hole Detection and Recovery.

In wireless sensor networks (WSNs), Radio Signal Strength Indicator (RSSI)-based localization techniques have been widely used in various applications, such as intrusion detection, battlefield surveillance, and animal monitoring. One fundamental performance measure in those applications is the sensing coverage of WSNs. Insufficient coverage will significantly reduce the effectiveness of the applications. However, most existing studies on coverage assume that the sensing range of a sensor node is a disk, and the disk coverage model is too simplistic for many localization techniques. Moreover, there are some localization techniques of WSNs whose coverage model is non-disk, such as RSSI-based localization techniques. In this paper, we focus on detecting and recovering coverage holes of WSNs to enhance RSSI-based localization techniques whose coverage model is an ellipse. We propose an algorithm inspired by Voronoi tessellation and Delaunay triangulation to detect and recover coverage holes. Simulation results show that our algorithm can recover all holes and can reach any set coverage rate, up to 100% coverage.

Identification of an lncRNA­miRNA­mRNA interaction mechanism in breast cancer based on bioinformatic analysis.

Non­coding RNAs serve important roles in regulating the expression of certain genes and are involved in the principal biological processes of breast cancer. The majority of studies have focused on defining the regulatory functions of long non­coding RNAs (lncRNAs) and microRNAs (miRNAs/miRs), and few studies have investigated how lncRNAs and miRNAs are transcriptionally regulated. In the present study, based on the breast invasive carcinoma dataset from The Cancer Genome Atlas at cBioPortal, and using a bioinformatics computational approach, an lncRNA­miRNA­mRNA network was constructed. The network consisted of 601 nodes and 706 edges, which represented the complex web of regulatory effects between lncRNAs, miRNAs and target genes. The results of the present study demonstrated that miR­510 was the most potent miRNA controller and regulator of numerous target genes. In addition, it was observed that the lncRNAs PVT1, CCAT1 and linc00861 exhibited possible interactions with clinical biomarkers, including receptor tyrosine­protein kinase erbB­2, estrogen receptor and progesterone receptor, demonstrated using RNA­protein interaction prediction software. The network of lncRNA­miRNA­mRNA interactions will facilitate further experimental studies and may be used to refine biomarker predictions for developing novel therapeutic approaches in breast cancer.

Discovery of alkyl bis(oxy)dibenzimidamide derivatives as novel protein arginine methyltransferase 1 (PRMT1) inhibitors.

Protein arginine methylation, a post-translational modification critical for a variety of biological processes, is catalyzed by protein arginine N-methyltransferases (PRMTs). In particular, PRMT1 is responsible for over 85% of the arginine methylation in mammalian cells. Dysregulation of PRMT1 is involved in diverse pathological diseases including cancers. However, most current PRMT1 inhibitors are lack of specificity, efficacy, and bioavailability. Herein, a series of alkyl bis(oxy)dibenzimidamide derivatives were identified as selective PRMT1 inhibitors. Among them, the most potent compound corresponds to hexamidine (IC50  = 5.9 ± 1.7 µm), which is an antimicrobial agent. The binding between hexamidine and PRMT1 was further validated by thermal shift assays and nuclear magnetic resonance (NMR) experiments. Molecular docking and NMR assays indicated that hexamidine occupied the substrate binding pocket. Furthermore, hexamidine effectively blocked cell proliferation in cancer cell lines related to PRMT1 overexpression. Taken together, this study has provided a druggable scaffold targeting PRMT1 as well as a new way to repurpose old drugs which is a complementary tool for the discovery of new lead compounds.

Passage of Magnetic Tat-Conjugated Fe3O4@SiO2 Nanoparticles Across In Vitro Blood-Brain Barrier.

Delivery of diagnostic or therapeutic agents across the blood-brain barrier (BBB) remains a major challenge of brain disease treatment. Magnetic nanoparticles are actively being developed as drug carriers due to magnetic targeting and subsequently reduced off-target effects. In this paper, we developed a magnetic SiO2@Fe3O4 nanoparticle-based carrier bound to cell-penetrating peptide Tat (SiO2@Fe3O4-Tat) and studied its fates in accessing BBB. SiO2@Fe3O4-Tat nanoparticles (NPs) exhibited suitable magnetism and good biocompatibility. NPs adding to the apical chamber of in vitro BBB model were found in the U251 glioma cells co-cultured at the bottom of the Transwell, indicating that particles passed through the barrier and taken up by glioma cells. Moreover, the synergistic effects of Tat and magnetic field could promote the efficient cellular internalization and the permeability across the barrier. Besides, functionalization with Tat peptide allowed particles to locate into the nucleus of U251 cells than the non-conjugated NPs. These results suggest that SiO2@Fe3O4-Tat NPs could penetrate the BBB through the transcytosis of brain endothelial cells and magnetically mediated dragging. Therefore, SiO2@Fe3O4-Tat NPs could be exploited as a potential drug delivery system for chemotherapy and gene therapy of brain disease.

[Effects of Yishen Tonglong Capsules on sex hormone levels in mice with benign prostatic hyperplasia].

OBJECTIVE: To study the effect of Yishen Tonglong Capsules (YTC) on the sex hormone levels in the mouse model of benign prostatic hyperplasia (BPH). METHODS: The BPH model was made in male mice by subcutaneous injection of testosterone propionate at 5 mg per kg of the body weight per day for 3 weeks. Then the model animals were divided into five groups of 10 in each: model control, Longbishu Capsules (LBS), and high-, medium- and low-dose YTC. Another 10 mice were included as normal controls. The mice in the LBS group were treated intragastrically with LBS at 0.45 g per kg of the body weight, those in the high-, medium- and low-dose YTC groups with YTC at 1.2, 0.6 and 0.3 g per kg of the body weight, and those in the model and normal control groups given the same volume of distilled water. After 8 weeks of treatment, the mice were sacrificed and their prostates taken for measurement of their wet weight, calculation of the prostatic index (PI), determination of the levels of serum testosterone (T), estradiol (E2) and E2/T ratio, and observation of the morphological changes of the prostate tissue under the light microscope. RESULTS: The wet weight of the prostate and PI were significantly decreased in the LBS and medium- and high-dose YTC groups as compared with the model control group (P<0.01). The serum T and E2 levels and E2/T ratio were (1.73±0.02) ng/ml, (73.08±1.03) pg/ml and 42.30±0.53 in the normal control, (3.86±0.02) ng/ml, (145.79±0.88) pg/ml and 37.76±0.25 in the model control, (2.47±0.02) ng/ml, (95.87±0.47) pg/ml and 38.80±0.13 in the LBS, (2.91±0.03) ng/ml, (112.68±0.77) pg/ml and 38.80±0.42 in the low-dose YTC, (2.77±0.02) ng/ml, (112.16±0.82) pg/ml and 40.56±0.29 in the medium-dose YTC, and (2.75±0.03) ng/ml, (107.11±0.61) pg/ml and 38.92±0.36 in the high-dose YTC group, all with statistically significant differences between the model control and the other groups (P<0.05 or P<0.01). CONCLUSIONS: Yishen Tonglong Capsules significantly reduced the levels of serum T and E2 and elevated the E2/T ratio in the mouse model of BPH, which manifested the action mechanism of Yishen Tonglong Capsules in the treatment of BPH.