Interaction of glycine with Li+ in the (H2O)n (n = 0-8) clusters.

CONTEXT: We investigated the interaction between glycine and Li+ in water environment based on the Gly·Li+(H2O)n (n = 0-8) cluster. Our study shows that for Gly·Li+, Li+ binds to both carbonyl oxygen and amino nitrogen to form a bidentate structure, and the first three water molecules preferentially interact with Li+. For n = 0-5, the complexes of Gly·Li+(H2O)n exist in neutral form, and when the water number reached 6, the complex can coexist in neutral and zwitterionic form, then zwitterionic structures are dominant for n = 7, 8. The analyses by RDG, AIM, and ESP in conjunction with the calculated interaction energies show that the interaction between Li+ and Gly decreases gradually with the water molecules involved successively from n = 1 to 6 and then increases for n = 7-8. Additionally, the infrared spectra of Gly·Li+(H2O)n (n = 0-8) are also calculated. METHODS: The initial structures were optimized using Gaussian 09 program package in B3LYP-D3 (BJ)/6-311G(d, p) method, and the frequency was calculated with 6-311 + G(2d, p) basis set. GaussView5.0.9 was used to view simulation infrared spectra. The noncovalent interaction method (NCl), energy decomposition (EDA), atoms in molecules (AIM) analysis, and electrostatic potential (ESP) analyses were conducted using Multiwfn software to gain a deeper understanding of the interaction properties of Gly, Li+, and water.

Convolutional neural network-based segmentation network applied to image recognition of angiodysplasias lesion under capsule endoscopy.

BACKGROUND: Small intestinal vascular malformations (angiodysplasias) are common causes of small intestinal bleeding. While capsule endoscopy has become the primary diagnostic method for angiodysplasia, manual reading of the entire gastrointestinal tract is time-consuming and requires a heavy workload, which affects the accuracy of diagnosis. AIM: To evaluate whether artificial intelligence can assist the diagnosis and increase the detection rate of angiodysplasias in the small intestine, achieve automatic disease detection, and shorten the capsule endoscopy (CE) reading time. METHODS: A convolutional neural network semantic segmentation model with a feature fusion method, which automatically recognizes the category of vascular dysplasia under CE and draws the lesion contour, thus improving the efficiency and accuracy of identifying small intestinal vascular malformation lesions, was proposed. Resnet-50 was used as the skeleton network to design the fusion mechanism, fuse the shallow and depth features, and classify the images at the pixel level to achieve the segmentation and recognition of vascular dysplasia. The training set and test set were constructed and compared with PSPNet, Deeplab3+, and UperNet. RESULTS: The test set constructed in the study achieved satisfactory results, where pixel accuracy was 99%, mean intersection over union was 0.69, negative predictive value was 98.74%, and positive predictive value was 94.27%. The model parameter was 46.38 M, the float calculation was 467.2 G, and the time length to segment and recognize a picture was 0.6 s. CONCLUSION: Constructing a segmentation network based on deep learning to segment and recognize angiodysplasias lesions is an effective and feasible method for diagnosing angiodysplasias lesions.

Penisarins A and B, Sesquiterpene Coumarins Isolated from an Endophytic Penicillium sp.

Penisarins A (1) and B (2), sesquiterpene coumarins with an unusual tricyclic sesquiterpene system, were isolated from endophytic Penicillium sp. KMU18029. Their structures were elucidated on the basis of spectroscopic methods, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Compound 2 showed significant cytotoxicities against two human cancer cell lines, HL-60 and SMMC-7721, with IC50 values of 3.6 ± 0.2 and 3.7 ± 0.2 µM, respectively.

Photochemical degradation of iodate by UV/H2O2 process: Kinetics, parameters and enhanced formation of iodo-trihalomethanes during chloramination.

In this paper, it was demonstrated that UV/H2O2 process can not only obviously promote the degradation rate of IO3-, but also greatly enhance iodo-trihalomethanes (I-THMs) formation in sequential chloramination. UV/H2O2 exhibited much faster IO3- decomposition than either UV or H2O2 treatment alone due to the contribution of highly reactive species including O-, OH and eaq-. The degradation rate of IO3- was affected by H2O2 dosages, pH, UV intensity as well as the presence of natural organic matter (NOM). The calculated pseudo-first order rate constant gradually increased with H2O2 dosages and solution pH, but behaved directly proportional to the UV intensity. Although NOM remarkably reduced the degradation rate of IO3- in UV/H2O2 process, their presence greatly enhanced the formation of I-THMs during subsequent chloramination. The overwhelming majority of iodoform at high UV fluences was also observed, which indicated improved iodination degrees of the detected I-THMs. UV/H2O2 was proved to be more capable on the evolution of IO3- to I- as well as I-THMs than UV and thereby enhanced the toxicity of disinfected waters in the following chloramination process. This study was among the first to provide a comprehensive understanding on the transformation of IO3- as the emerging iodine precursor to form I-THMs via diverse advanced oxidation process technologies like UV/H2O2.

BCL2 promotor methylation and miR-15a/16-1 upregulation is associated with sanguinarine-induced apoptotic death in rat HSC-T6 cells.

Previous studies show that several pathways are involved in sanguinarine-induced apoptotic cell death, including AKT downregulation, inhibition of NF-kB activation, mediation of ROS production, downregulation of anti-apoptosis proteins XIAP and cIAP-1, upregulation of BAX, and downregulation of BCL2. In this study, we found out that the quenching of ROS generation by N-acetyl-l-cysteine (NAC), a scavenger of ROS, reversed sanguinarine-induced apoptosis effects, also we found out that sanguinarine-induced rat hepatic stellate T6 cells (HSC-T6 cells) apoptosis was correlated with the generation of increased ROS, which was followed by the activation of caspase-8 (-3, -6, and -9), and the decreasing in the miltochondrial membrane potential (MMP) and the down-regulation of anti-apoptotic protein Bcl-2. It is not clear whether BCL2's downregulation relates to its promoter methylation and miR-15a/16-1 expression which can bind to BCL2 3'-UTR (un-translation reagon). We showed that sanguinarine-induced down regulation of BCL2 was associated with the increased methylation rate of BCL2 promotor district and the increased expression of miR-15a/16-1. HSC-T6 cells treatment with 5-Aza-2'-deoxycytidine (5'-Aza-CdR) impeded sanguinarine-induced BCL2 promotor district methylation and recovered BCL2's expression. Over expression of BCL2 using pEGFP-N1 vector decreased sanguinarine-induced HSC-T6 cells apoptotic death significantly but not completely. These observations clearly showed that BCL2 down regulation was associated with its promoter methylation and miR-15a/16-1 upregulation in sanguinarine-induced Rat HSC-T6 cells.

Study of the inhibitory effect of fatty acids on the interaction between DNA and polymerase beta.

The binding of human DNA polymerase beta (pol beta) to DNA template-primer duplex and single-stranded DNA in the absence or presence of pol beta inhibitors has been studied using a surface plasmon resonance biosensor. Two fatty acids, linoleic acid and nervonic acid, were used as potent pol beta inhibitors. In the interaction between pol beta and DNA, pol beta could bind to ssDNA in a single binding mode, but bound to DNA template-primer duplexes in a parallel mode. Both pol beta inhibitors prevented the binding of pol beta to the single strand overhang and changed the binding from parallel to single mode. The affinities of pol beta to the template-primer duplex region in the presence of nervonic acid or linoleic acid were decreased by 20 and 5 times, respectively. The significant inhibitory effect of nervonic acid on the pol beta-duplex interaction was due to both a 2-fold decrease in the association rate and a 9-fold increase in the dissociation rate. In the presence of linoleic acid, no significant change of association rate was observed, and the decrease in binding affinity of pol beta to DNA was mainly due to 7-fold increase in the dissociation rate.

Metastatic choriocarcinoma in a middle-aged man presenting as a right thigh mass with venous thrombosis: a case report.

Choriocarcinoma is a highly aggressive beta-subunit of human chorionic gonadotropin (betaHCG)-producing germ cell tumor. In men, it is a rare neoplasm and can arise in the testes or in various extragonadal locations such as the retroperitoneum, mediastinum, and pineal body. We present a highly unusual case of a middle-aged man with primary metastatic betaHCG-producing choriocarcinoma of the right thigh along with right lower-extremity venous thrombosis. We comment on prognostic variables as well as discuss several theories to account for the unusual location of his choriocarcinoma.