Discrete Latent Factor Model for Cross-Modal Hashing.

Due to its storage and retrieval efficiency, cross-modal hashing (CMH) has been widely used for cross-modal similarity search in many multimedia applications. According to the training strategy, existing CMH methods can be mainly divided into two categories: relaxation-based continuous methods and discrete methods. In general, the training of relaxation-based continuous methods is faster than that of discrete methods, but the accuracy of relaxation-based continuous methods is not satisfactory. On the contrary, the accuracy of discrete methods is typically better than that of the relaxation-based continuous methods, but the training of discrete methods is very time-consuming. In this paper, we propose a novel CMH method, called Discrete Latent Factor model-based cross-modal Hashing (DLFH), for cross modal similarity search. DLFH is a discrete method which can directly learn the binary hash codes for CMH. At the same time, the training of DLFH is efficient. Experiments show that the DLFH can achieve significantly better accuracy than existing methods, and the training time of DLFH is comparable to that of the relaxation-based continuous methods which are much faster than the existing discrete methods.

Deep Discrete Supervised Hashing.

Hashing has been widely used for large-scale search due to its low storage cost and fast query speed. By using supervised information, supervised hashing can significantly outperform unsupervised hashing. Recently, discrete supervised hashing and feature learning based deep hashing are two representative progresses in supervised hashing. On one hand, hashing is essentially a discrete optimization problem. Hence, utilizing supervised information to directly guide discrete (binary) coding procedure can avoid sub-optimal solution and improve the accuracy. On the other hand, feature learning based deep hashing, which integrates deep feature learning and hash-code learning into an end-to-end architecture, can enhance the feedback between feature learning and hash-code learning. The key in discrete supervised hashing is to adopt supervised information to directly guide the discrete coding procedure in hashing. The key in deep hashing is to adopt the supervised information to directly guide the deep feature learning procedure. However, most deep supervised hashing methods cannot use the supervised information to directly guide both discrete (binary) coding procedure and deep feature learning procedure in the same framework. In this paper, we propose a novel deep hashing method, called deep discrete supervised hashing (DDSH). DDSH is the first deep hashing method which can utilize pairwise supervised information to directly guide both discrete coding procedure and deep feature learning procedure and thus enhance the feedback between these two important procedures. Experiments on four real datasets show that DDSH can outperform other state-of-the-art baselines, including both discrete hashing and deep hashing baselines, for image retrieval.

RNA interference-mediated silencing of focal adhesion kinase inhibits growth of human colon carcinoma xenograft in nude mice.

Focal adhesion kinase (FAK), which plays a pivotal role in mediating cell proliferation, survival and migration, is frequently overexpressed in human colon cancer. In the present study, we utilized the short hairpin RNA (shRNA) to knock down the expression of FAK in SW480 human colon cancer cells in vitro. Furthermore, nude mice bearing human colon carcinoma SW480 were established and treated with plasmids encoding FAK shRNA encapsulated in DOTAP: Chol cationic liposome through tail vein injection. Tumor growth and potential side effect were observed during the treatment. Assessments of angiogenesis, cell proliferation, and apoptosis were performed by using immunohistochemistry against CD31, proliferating cell nuclear antigen (PCNA) and TUNEL assays, respectively. The results indicated that DOTAP: Chol could efficiently deliver the therapeutic plasmids systemically to tumor xenografts, resulting in suppression of tumor growth. Treatment with plasmid encoding FAK-targeted shRNA reduced mean tumor volume by approximately 86% compared with control groups (p < 0.01), accompanied with angiogenesis inhibition (p < 0.05), tumor cell proliferation suppression (p < 0.05) and apoptosis induction (p < 0.05). Taken together, our data demonstrated that shRNA-mediated silencing of FAK might be a potential therapeutic approach against human colon carcinoma.

[SEREX screening of human placenta antigens].

OBJECTIVE: To screen and obtain the potential human placenta antigens for the further application with serological analysis of recombinant cDNA expression library (SEREX). METHODS: SEREX technique with some modifications was applied. In brief, immune sera from rabbit immunized with human chorionic tissue were used to screen human placenta tissue cDNA expression library. Positive clone plaques were obtained after two rounds of screen. And the positive clone plaques were purified and sequenced. BLAST software was applied to comparison the obtained sequences with those found in GenBank for bioinformatic analysis. RESULTS: 69 positive clones were obtained from two rounds of screen. They were derived from 12 different genes, 9 of these were genes of known biology function, and 3 were genes of unknown biology function depending on the sequence analysis. Among the positive clones, chorionic somatomammotropin hormone 1 and 2 genes (CSH1 and CSH2) were found in 57 of positive clones (82.6%). This implied that the CSH1 and CSH2 might be the gene of encoding the important antigen and other genes obtained were related to the development of embryo. CONCLUSION: Modified xenogeneic immune SEREX technology is a very effective method to screen and isolate human placenta antigens. These antigens identified from this study might contribute to clarify the process of embryo development.

Effects of total flavonoids of Hippophae rhamnoides L. on intracellular free calcium in cultured vascular smooth muscle cells of spontaneously hypertensive rats and Wistar-Kyoto rats.

OBJECTIVE: To explore the effects of total flavonoids of Hippophae rhamnoides L. (TFH), quercetin (Que) and isorhamnetin (Isor) on the intracellular free calcium ([Ca(2+)](i)) in vascular smooth muscle cells (VSMC) of spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). METHODS: Fluo 3-acetoxymethylester (Fluo-3/AM) was used to observe the effects of TFH (100 mg/L) and its essential monomers, namely Que (10(-4) mol/L) and Isor (10(-4) mol/L) on changes of [Ca(2+)](i) in cultured SHR and WKY VSMC (abbr. to Ca-SHR & Ca-WKY) following exposure to high K(+), norepinephrine (NE) and angiotensin II (Ang II), and to compare with the effects of verapamil (Ver). RESULTS: (1) TFH, Que and Isor had inhibitory effects on resting Ca-SHR (P < 0.05), but had no significant effects on Ca-WKY (P > 0.05). (2) High K(+) could increase Ca-SHR more significantly than Ca-WKY (P < 0.05); TFH, Que and Isor could inhibit the elevation of [Ca(2+)](i) induced by high K(+)-depolarization, with the effects similar to that of Ver, and the effect on Ca-SHR was more significant than that on Ca-WKY (P < 0.05). (3) NE and Ang II could increase Ca-SHR more significantly than Ca-WKY (P < 0.05), TFH, Que and Isor had remarkably inhibitory effect on the elevation of Ca-SHR and Ca-WKY induced by NE or Ang II. (4) In the absence of extracellular Ca(2+), TFH, Que and Isor also had certain inhibitory effect on Ca-SHR and Ca-WKY induced by NE, and the effect on the former was more significant than that on the latter (P < 0.05). CONCLUSION: TFH, Que and Isor might decrease the levels of [Ca(2+)](i) in VSMCs by blocking both voltage-dependent calcium channels (VDC) and receptor-operated calcium channels (ROC) in physiological or pathological state, which may be one of the important mechanisms of their hypotensive and protective effects on target organs in patients with hypertension.