A Novel Clustering Tree-based Video lookup Strategy for Supporting VCR-like Operations in MANETs

Mobile Peer-to-Peer (MP2P) network is a promising avenue for large-scale deployment of Video-on-Demand (VoD) applications over mobile ad-hoc networks (MANETs). In P2P VoD systems, fast search for resources is key determinants for improving the Quality of Service (QoS) due to the low delay of seeking resources caused by streaming interactivity. In this paper, we propose a novel Clustering Tree-based Video Lookup strategy for supporting VCR-like operations in MANETs (CTVL) CTVL selects the chunks with the high popularity as "overlay router" chunks to build the "virtual connection" with other chunks in terms of the popularities and external connection of video chunks. CTVL designs a new clustering strategy to group nodes in P2P networks and a maintenance mechanism of cluster structure, which achieves the high system scalability and fast resource search performance. Thorough simulation results also show how CTVL achieves higher average lookup success rate, lower maintenance cost, lower average end-to-end delay and lower packet loss ratio (PLR) in comparison with other state of the art solutions

A Kazal-Type Serine Protease Inhibitor from the Defense Gland Secretion of the Subterranean Termite Coptotermes formosanus Shiraki

Coptotermes formosanus is an imported, subterranean termite species with the largest economic impact in the United States. The frontal glands of the soldier caste termites comprising one third of the body mass, contain a secretion expelled through a foramen in defense. The small molecule composition of the frontal gland secretion is well-characterized, but the proteins remain to be identified. Herein is reported the structure and function of one of several proteins found in the termite defense gland secretion. TFP4 is a 6.9 kDa, non-classical group 1 Kazal-type serine protease inhibitor with activity towards chymotrypsin and elastase, but not trypsin. The 3-dimensional solution structure of TFP4 was solved with nuclear magnetic resonance spectroscopy, and represents the first structure from the taxonomic family, Rhinotermitidae. Based on the structure of TFP4, the protease inhibitor active loop (Cys8 to Cys16) was identified

Cryo-EM Structure of Mechanosensitive Channel YnaI Using SMA2000: Challenges and Opportunities

Mechanosensitive channels respond to mechanical forces exerted on the cell membrane and play vital roles in regulating the chemical equilibrium within cells and their environment. Highresolution structural information is required to understand the gating mechanisms of mechanosensitive channels. Protein-lipid interactions are essential for the structural and functional integrity of mechanosensitive channels, but detergents cannot maintain the crucial native lipid environment for purified mechanosensitive channels. Recently, detergent-free systems have emerged as alternatives for membrane protein structural biology. This report shows that while membrane-active polymer, SMA2000, could retain some native cell membrane lipids on the transmembrane domain of the mechanosensitive-like YnaI channel, the complete structure of the transmembrane domain of YnaI was not resolved. This reveals a significant limitation of SMA2000 or similar membrane-active copolymers. This limitation may come from the heterogeneity of the polymers and nonspecific interactions between the polymers and the relatively large hydrophobic pockets within the transmembrane domain of YnaI. However, this limitation offers development opportunities for detergent-free technology for challenging membrane proteins

Developing a questionnaire to evaluate the health information literacy in China

IntroductionHealth information literacy is critical for individuals to obtain, understand, screen, and apply health information. However, there is currently no specific tool available to evaluate all four dimensions of health information literacy in China. Public health emergencies can present an opportunity to evaluate and monitor the health information literacy level of residents. Therefore, this study aimed to develop a questionnaire to evaluate the level of health information literacy and to measure the reliability and validity.MethodsThe development process of the questionnaire consisted of the determination of questionnaire items, expert consultation, and validation. Based on the National Residents Health Literacy Monitoring Questionnaire (2020) and the 2019 Informed Health Choices key concepts, the researchers drafted the questionnaire, including all four dimensions of health information literacy. Experts in relevant fields were invited to evaluate the draft questionnaire, and revisions were made accordingly. Finally, the reliability and validity of the finalized version were examined in Gansu Province, China.ResultsThe research team preliminarily formulated 14 items encompassing the four dimensions of health information literacy. After consulting with 28 experts, modifications were made. A convenience sample of 185 Chinese residents was invited to participate. Cronbach's alpha coefficient was 0.715 and McDonald's omega was 0.739 for internal consistency, and the test-retest intra-class correlation coefficient after 4 weeks was 0.906, indicating that the questionnaire content and measurement structure was relatively stable.ConclusionThis questionnaire is the first evidence-based assessment tool developed for monitoring health information literacy in China, and it has shown good reliability and validity. It can help to monitor the health information literacy levels of Chinese residents, promote evidence-based decision-making, and guide interventions to improve health information literacy

Be Cautious with Crystal Structures of Membrane Proteins or Complexes Prepared in Detergents

Membrane proteins are an important class of macromolecules found in all living organisms and many of them serve as important drug targets. In order to understand their biological and biochemical functions and to exploit them for structure-based drug design, high-resolution and accurate structures of membrane proteins are needed, but are still rarely available, e.g., predominantly from X-ray crystallography, and more recently from single particle cryo-EM — an increasingly powerful tool for membrane protein structure determination. However, while protein-lipid interactions play crucial roles for the structural and functional integrity of membrane proteins, for historical reasons and due to technological limitations, until recently, the primary method for membrane protein crystallization has relied on detergents. Bicelle and lipid cubic phase (LCP) methods have also been used for membrane protein crystallization, but the first step requires detergent extraction of the protein from its native cell membrane. The resulting, crystal structures have been occasionally questioned, but such concerns were generally dismissed as accidents or ignored. However, even a hint of controversy indicates that methodological drawbacks in such structural research may exist. In the absence of caution, structures determined using these methods are often assumed to be correct, which has led to surprising hypotheses for their mechanisms of action. In this communication, several examples of structural studies on membrane proteins or complexes will be discussed: Resistance-Nodulation-Division (RND) family transporters, microbial rhodopsins, Tryptophan-rich Sensory Proteins (TSPO), and Energy-Coupling Factor (ECF) type ABC transporters. These analyses should focus the attention of membrane protein structural biologists on the potential problems in structure determination relying on detergent-based methods. Furthermore, careful examination of membrane proteins in their native cell environments by biochemical and biophysical techniques is warranted, and completely detergent-free systems for membrane protein research are crucially needed

A snapshot of the unity and diversity of biological systems at the level of chemistry : structural and mechanistic studies of Cg10062, a homologue of cis-3-chloroacrylic acid dehalogenase, FG41 malonate semialdehyde decarboxylase and the catalytic domain of pyruvate dehydrogenase phosphatase 1

textThe tautomerase superfamily is composed of a group of proteins characterized by two key features: the N-terminal proline and a beta-alpha-beta-motif. This superfamily has been divided into five families represented by 4-oxalocrotonate tautomerase (4-OT), 5-(carboxymethyl)-2-hydroxymuconate isomerase (CHMI), cis-3-chloroacrylic acid dehalogenase (cis-CaaD), malonate semialdehyde decarboxylase (MSAD), and macrophage migration inhibitory factor (MIF). Cg10062 is a homologue of cis-CaaD, but has several distinct biochemical properties from cis-CaaD. For example, Cg10062 can be irreversibly inhibited by (R)- or (S)-oxirane-2-carboxylate, whereas cis-CaaD can only be irreversibly inhibited by (R)-oxirane-2-carboxylate. FG41MSAD is a homologue of MSAD, with comparable decarboxylase activity but missing Arg-73 known to be crucial for the MSAD activity. In order to understand the unique biochemical characteristics of Cg10062 and FG41MSAD, we have solved five crystal structures. These crystal structures have established a solid structural basis for understanding the mechanisms of their activities. The eukaryotic protein phosphatases are composed of a group of proteins that are responsible for reversible phosphorylation. The eukaryotic protein phosphatases have been divided into three families, the phosphoprotein phosphatase (PPP) family, the protein phosphatase Mg2+- or Mn2+-dependent (PPM) family and the protein Tyr phosphatase (PTP) family. PDP1 is a member of PPM family. PDP1 is also an important component of the large pyruvate dehydrogenase complex (PDC) which catalyzes the decarboxylation of pyruvate to yield acetyl-CoA with the accompanying reduction of NAD+. In order to understand the mechanism in which it dephosphorylates its target protein we have solved the structure of the catalytic domain of PDP1. Analysis of these structures in the light of their evolutionary contexts enables us to appreciate the unity and diversity of the biological systems at the chemical level and help us solve interesting problems, such as the possible physiological functions for some members within the tautomerase superfamily.Pharmac

Xuebijing Administration Alleviates Pulmonary Endothelial Inflammation and Coagulation Dysregulation in the Early Phase of Sepsis in Rats

Ethnopharmacological relevance: Xuebijing injection is a Chinese herbal-derived drug composed of radix paeoniaerubra, rhizomachuanxiong, Salvia miltiorrhiza, floscarthami, and Angelica sinensis. This study aimed to investigate the effects of Xuebijing administration on pulmonary endothelial injury and coagulation dysfunction in a cecal ligation and puncture (CLP)-induced sepsis rat model. Materials and methods: A CLP-induced sepsis rat model was established. The CLP rats were treated with a vehicle or Xuebijing via intravenous infusion and sacrificed at 2, 4, 6, 8, or 12 h after CLP for lung tissue and blood sample collection. The mean arterial pressure (MAP) was monitored. Transmission microscopy examination and H&E staining were performed to observe pulmonary structural alterations. Enzyme linked immunosorbent assay (ELISA) was performed to measure the plasma levels of epithelial markers, proinflammatory cytokines, and coagulation-related proteins. Results: Compared with vehicle treatment, Xuebijing administration maintained the MAP in the normal range until 11 h after CLP. Transmission microscopy and H&E staining revealed that Xuebijing administration alleviated alveolar–capillary barrier impairments and lung inflammation in CLP rats. ELISA showed that Xuebijing administration effectively reversed CLP-induced elevations in the plasma levels of epithelial markers endothelin-1 and von Willebrand factor, starting 6 and 8 h after CLP, respectively. Xuebijing administration also significantly abolished CLP-induced rises in circulating proinflammatory cytokines interleukin 6 (IL-6) at 6 h after CLP, IL-1β at 2 and 12 h after CLP, and TNF-α at 2, 4, 6, 8, and 12 h after CLP. In addition, Xuebijing administration strongly reversed CLP-induced alterations in circulating active protein C and tissue-type plasminogen activator, starting 4 h and 2 h after CLP, respectively. Conclusions: Xuebijing ameliorates pulmonary endothelial injury, systemic inflammation, and coagulation dysfunction in early sepsis

The Plasma DIA-Based Quantitative Proteomics Reveals the Pathogenic Pathways and New Biomarkers in Cervical Cancer and High Grade Squamous Intraepithelial Lesion

Objective: The process of normal cervix changing into high grade squamous intraepithelial lesion (HSIL) and invasive cervical cancer is long and the mechanisms are still not completely clear. This study aimed to reveal the protein profiles related to HSIL and cervical cancer and find the diagnostic and prognostic molecular changes. Methods: Data-independent acquisition (DIA) analysis was performed to identify 20 healthy female volunteers, 20 HSIL and 20 cervical patients in a cohort to screen differentially expressed proteins (DEPs) for the HSIL and cervical cancer. Subsequently, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were used for functional annotation of DEPs; the protein–protein interaction (PPI) and weighted gene co-expression network analysis (WGCNA) were performed for detection of key molecular modules and hub proteins. They were validated using the Enzyme-Linked Immunosorbent Assay (ELISA). Results: A total of 243 DEPs were identified in the study groups. GO and KEGG analysis showed that DEPs were mainly enriched in the complement and coagulation pathway, cholesterol metabolism pathway, the IL-17 signaling pathway as well as the viral protein interaction with cytokine and cytokine receptor pathway. Subsequently, the WGCNA analysis showed that the green module was highly correlated with the cervical cancer stage. Additionally, six interesting core DEPs were verified by ELISA, APOF and ORM1, showing nearly the same expression pattern with DIA. The area under the curve (AUC) of 0.978 was obtained by using ORM1 combined with APOF to predict CK and HSIL+CC, and in the diagnosis of HSIL and CC, the AUC can reach to 0.982. The high expression of ORM1 is related to lymph node metastasis and the clinical stage of cervical cancer patients as well as the poor prognosis. Conclusion: DIA-ELSIA combined analysis screened and validated two previously unexplored but potentially useful biomarkers for early diagnosis of HSIL and cervical cancer, as well as possible new pathogenic pathways and therapeutic targets