Constrained Optimization Design of an Ion Focusing System with Wide Range of Energy Adjustment

For the study of ion scattering from solid surface, it is required that the energy of ions can be adjusted widely. The constrained optimization design of an ion focusing system with wide energy range and the magnification less than unity using the improved complex method is proposed in the present paper. This ion focusing system is suitable for use in the low energy ion scattering spectroscopy (ISS) and secondary ion mass spectroscopy (SIMS)

Genistein promotes cell death of ethanol-stressed HeLa cells through the continuation of apoptosis or secondary necrosis.

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.BACKGROUND: Apoptosis is a major target and treatment effect of multiple chemotherapeutical agents in cancer. A soybean isoflavone, genistein, is a well-studied chemopreventive agent and has been reported to potentiate the anticancer effect of some chemotherapeutics. However, its mechanistic basis of chemo-enhancement effect remains to be fully elucidated. METHODS: Apoptotic features of low concentration stressed cancer cells were studied by microscopic method, western blot, immunostaining and annexin V/PI assay. Genistein's effects on unstressed cells and recovering cells were investigated using MTT cell viability assay and LDH cytotoxicity assay. Quantitative real-time PCR was employed to analyze the possible gene targets involved in the recovery and genistein's effect. RESULTS: Low-concentration ethanol stressed cancer cells showed apoptotic features and could recover after stress removal. In stressed cells, genistein at sub-toxic dosage promoted the cell death. Quantitative real-time PCR revealed the up-regulation of anti-apoptotic genes MDM2 and XIAP during the recovery process in HeLa cells, and genistein treatment suppressed their expression. The application of genistein, MDM2 inhibitor and XIAP inhibitor to the recovering HeLa cells caused persistent caspase activity and enhanced cell death. Flow cytometry study indicated that genistein treatment could lead to persistent phosphatidylserine (PS) externalization and necrotic events in the recovering HeLa cells. Caspase activity inhibition shifted the major effect of genistein to necrosis. CONCLUSIONS: These results suggested two possible mechanisms through which genistein promoted cell death in stressed cancer cells. Genistein could maintain the existing apoptotic signal to enhance apoptotic cell death. It could also disrupt the recovering process in caspase-independent manner, which lead to necrotic events. These effects may be related to the enhanced antitumor effect of chemotherapeutic drugs when they were combined with genistein

Totally thoracoscopic closure of ventricular septal defect without a robotically assisted surgical system: A summary of 119 cases

ObjectivesTo summarize the clinical outcomes of totally thoracoscopic closure of a ventricular septal defect (VSD).MethodsTotally thoracoscopic VSD closure was performed in 119 patients (66 boys; mean age, 7.1 ± 3.6 years). An additional 35 patients undergoing open-chest VSD closure were selected as a control group. Using 3 port incisions in the right chest, pericardiotomy, bicaval occlusion, atriotomy, and VSD closure were performed by thoracoscopy without the aid of a robotically assisted surgical system.ResultsCardiopulmonary bypass and aortic crossclamp times were 42.2 ± 9.8 and 32.5 ± 7.3 minutes, respectively. There were no deaths but 1 patient required insertion of a permanent pacemaker as a result of postoperative atrioventricular conduction block. The length of stay in the intensive care unit (11.0 ± 2.6 vs 22.9 ± 4.9 hours, P < .01) or postoperative hospital stay (4.2 ± 1.1 vs 6.6 ± 2.1 days, P < .03) in the thoracoscopic group were shorter than in the control group. The percentage of patients who required postoperative opioid analgesics in the thoracoscopic group was lower than in the control group (31.9% vs 74.2%, P < .001). Rate of blood transfusion during the operation (17.6% vs 65.7%, P = .001) and the postoperative use of opioid analgesics (31.9% vs 74.3%, P = .003) in the thoracoscopic group was lower than in the control group. Transesophageal echocardiographic analysis 4.6 ± 2.3 months after the operation showed complete closure of the defect.ConclusionsTotally thoracoscopic closure of VSD through a 3-port entry was safe and effective

1H-Benzimidazole-2(3H)-thione

The asymmetric unit of the title compound, C7H6N2S, contains one half-mol­ecule; the C and S atoms of the C=S group lie on a crystallographic mirror plane. In the crystal structure, inter­molecular N—H⋯S hydrogen bonds link the mol­ecules

Progress in host–guest macrocycle/pesticide research: Recognition, detection, release and application

Macrocyclic compounds are formed via a series of cyclic oligomers possessing repeating units, and classical examples include cyclodextrins, calix[n]arenes, cucurbit[n]urils and pillar[n]arenes (n represents the number of repeat units). Given their unique host–guest binding ability, macrocycles are often developed as hosts for specific guest molecular assembly systems, adsorption materials, drug delivery carriers, catalysts, and molecular recognition systems. For example, macrocyclic host molecules are widely used to encapsulate hydrophobic drug molecules to improve both the solubility and utilization efficiency of the drug. One type of potential host molecule that has seen increased agricultural use in recent years are pesticides. This includes herbicides, insecticides, and fungicides, and given the increased use, there is need to develop systems that can rapidly and effectively identify and detect such pesticides. In this review, we will discuss the use of cucurbit[n]urils, pillar[n]arenes, calix[n]arenes, cyclodextrins in this area, and their ability to form host–guest species with herbicides, insecticides and fungicides. Particular emphasis is given to the ability of such systems to improve the toxicity and release of the pesticide and the potential for practical application