637 research outputs found
Recent advances in crystalline oxidopolyborate complexes of d-block or p-block metals: structural aspects, syntheses and physical properties
Crystalline materials containing hybrid inorganic–organic metal borates (complexes with oxidoborate ligands) display a variety of novel framework building blocks. The structural aspects of these hybrid metallaoxidoborates containing Cd(II), Co(II), Cu(II), Ga(III), In(III), Mn(II), Ni(II) or Zn(II) metal centers are discussed in this review. The review describes synthetic approaches to these hybrid materials, their physical properties, their spectroscopic properties and their potential applications
Short Intussusception Valves Prevent Reflux After Jejunal Interposition Bilioduodenal Anastomosis
Short whole circumference and semi-circumference intussusception valves were created in interposition
cholecysto-jejunal-duodenal conduits in pigs to determine which method best prevented gastrointestinal
reflux into the biliary tract. Following intravenous injection of 99 mTc-HIDA the time interval for its
excretion from the liver and appearance in the duodenum was not different in either whole or semi-circumference
valve animals or in controls without valves. After intragastric administration of 99 mTc-DTPA the relative radioactivity of gallbladder contents (reflux) in the cohort without valves was
significantly higher than in both cohorts with valves. Animals with semi-circumferential valves in turn
had significantly higher levels of nuclide than those with whole circumference valves. Reflux was
observed grossly in 100% of animals without valves, in 20% of those with semi-circumference valves,
and in no animals with whole circumference valves. This study indicates that both Whole and semi-circumference
intussusception valves placed in jejunal biliary conduits allow unimpeded flow of bile into
the gastrointestinal tract. Whole circumference valves are more effective for prevention of reflux than
semi-circumferential valves
The pan-inhibitor of Aurora kinases danusertib induces apoptosis and autophagy and suppresses epithelial-to-mesenchymal transition in human breast cancer cells
Danusertib (Danu) is a pan-inhibitor of Aurora kinases and a third-generation breakpoint cluster region-Abelson murine leukemia viral oncogene homolog 1 (Bcr-Abl) tyrosine kinase inhibitor, but its antitumor effect and underlying mechanisms in the treatment of human breast cancer remain elusive. This study aimed to investigate the effects of Danu on the growth, apoptosis, autophagy, and epithelial-to-mesenchymal transition (EMT) and the molecular mechanisms in human breast cancer MCF7 and MDA-MB-231 cells. The results demonstrated that Danu remarkably inhibited cell proliferation, induced apoptosis and autophagy, and suppressed EMT in both breast cancer cell lines. Danu arrested MCF7 and MDA-MB-231 cells in G2/M phase, accompanied by the downregulation of cyclin-dependent kinase 1 and cyclin B1 and upregulation of p21 Waf1/Cip1, p27 Kip1, and p53. Danu significantly decreased the expression of B-cell lymphoma-extra-large (Bcl-xl) and B-cell lymphoma 2 (Bcl-2), but increased the expression of Bcl-2-associated X protein (Bax) and p53-upregulated modulator of apoptosis (PUMA), and promoted the cleavage of caspases 3 and 9. Furthermore, Danu significantly increased the expression levels of the membrane-bound microtubule-associated protein 1A/1B-light chain 3 (LC3-II) and beclin 1 in breast cancer cells, two markers for autophagy. Danu induced the activation of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases 1 and 2 (Erk1/2) and inhibited the activation of protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathways in breast cancer cells. Treatment with wortmannin (a phosphatidylinositol 3-kinase inhibitor) markedly inhibited Danu-induced activation of p38 MAPK and conversion of cytosolic LC3-I to membrane-bound LC3-II. Pharmacological inhibition and small interfering RNA-mediated knockdown of p38 MAPK suppressed Akt activation, resulting in LC3-II accumulation and enhanced autophagy. Pharmacological inhibition and small interfering RNA-mediated knockdown of Erk1/2 also remarkably increased the level of LC3-II in MCF7 cells. Moreover, Danu inhibited EMT in both MCF7 and MDA-MB-231 cells with upregulated E-cadherin and zona occludens protein 1 (ZO-1) but downregulated N-cadherin, zinc finger E-box-binding homeobox 1 (TCF8/ZEB1), snail, slug, vimentin, and β-catenin. Notably, Danu showed lower cytotoxicity toward normal breast epithelial MCF10A cells. These findings indicate that Danu promotes cellular apoptosis and autophagy but inhibits EMT in human breast cancer cells via modulation of p38 MAPK/Erk1/2/Akt/mTOR signaling pathways. Danu may represent a promising anticancer agent for breast cancer treatment. More studies are warranted to fully delineate the underlying mechanisms, efficacy, and safety of Danu in breast cancer therapy
On the efficacy of anthracene isomers for triplet transmission from CdSe nanocrystals
The effect of isomeric substitutions on the transmitter for triplet energy transfer (TET) between nanocrystal (NC) donor and molecular acceptor is investigated. Each isomeric acceptor is expected to bind in a unique orientation with respect to the NC donor. We see that this orbital overlap drastically affects the transmission of triplets. Here, two functional groups, the carboxylic acid and dithiocarbamate, were varied between the 1-, 2- and 9-positions of the anthracene ring to give three ACA and three ADTC isomers. These six anthracene isomers served as transmitters for triplets between CdSe NC sensitizers and 9,10-diphenylanthracene annihilators for photon upconversion. The photon upconversion quantum yield (QY) is the highest for 9-ACA (12%), lowest for 9-ADTC (0.1%), around 3% for both 1-ACA and 1-ADTC, and about 1% for the 2-isomers. These trends in QYs are reflected in the rates of TET given by ultrafast transient absorption spectroscopy where a maximum of 3.8 × 107 s−1 for 9-ACA was measured. Molecular excited state energy levels were measured both in solution and polymer hosts to correlate structure to TET. This work confirms that anthracene excited states levels are very sensitive to molecular substitution, which in combination with orbital overlap, critically affect Dexter-based TET.Instituto de Investigaciones FisicoquÃmicas Teóricas y Aplicada
Lessons Learned of NSPO’s Picosatellite Mission: Yamsat - 1A, 1B & 1C
The YamSat is the first developed picosatellite in National Space Program Office’s (NSPO), Taiwan, R.O.C. It is scheduled to flight in the CubeSat launch in 2003. The rapid-prototyping system engineering different from the past formal discipline opens a new satellite development model in NSPO. The YamSat Test Readiness Review Meeting was successfully held in January 2002 and the environmental tests were completed by end March 2002. Besides the breadboard model and engineering test bed to prove of operation concept are built, three YamSats (1A, 1B, & 1C) instead of one are manufactured with slightly different configurations and purposes. The YamSat- 1A is for flight with ambitious and novel R.O.C. made components, including 15 domestic organizations and companies’ participation. The YamSat-1B is basically for backup purpose and demonstration, whereas the YamSat-1C is for amateur communication experiment end-to-end field test, and for public education purpose. This new experience gives fruitful lessons learned and provides low cost space experimentation and education to the next built picosatellites in Taiwan’s universities. Detailed mission and lessons learned are addressed in this paper
Comparison of secondary signs as shown by unenhanced helical computed tomography in patients with uric acid or calcium ureteral stones
AbstractUnenhanced helical computed tomography (UHCT) has evolved into a well-accepted diagnostic method in patients with suspected ureterolithiasis. UHCT not only shows stones within the lumen of the ureter, it also permits evaluation of the secondary signs associated with ureteral obstruction from stones. However, there we could find no data on how secondary signs might differ in relation to different compositions of ureteral stones. In this study, we compared the degree of secondary signs revealed by UHCT in uric acid stone formers and in patients forming calcium stones. We enrolled 117 patients with ureteral stones who underwent UHCT examination and Fourier transform infra-red analysis of stone samples. Clinical data were collected as follows: age, sex, estimated glomerular filtration rate (eGFR), urine pH, and radiological data on secondary signs apparent on UHCT. The uric acid stone formers had significantly lower urine pH and eGFR in comparison to calcium stone formers, and on UHCT they also had a higher percentage of the secondary signs, including rim sign (78.9% vs. 60.2%), hydroureter (94.7% vs. 89.8%), perirenal stranding (84.2% vs. 59.2%) and kidney density difference (73.7% vs. 50.0%). The radiological difference was statistically significant for perirenal stranding (p=0.041). In conclusion, we found that UHCT scanning reveals secondary signs to be more frequent in patients with uric acid ureteral stones than in patients with calcium stones, a tendency that might result from an acidic urine environment
Chinese herbal decoction as a complementary therapy for atrophic gastritis: a systematic review and meta-analysis
Background: Chinese herbal decoction (CHD) has been extensively used in the treatment of atrophic gastritis (AG) in China and other Far Eastern countries. We conducted a systematic review and meta-analysis to estimate the efficacy and safety of CHD in AG.Materials and Methods: Pubmed, Embase, Cochrane central register of controlled trials (central), VIP, China National Knowledge Infrastructure, Sinomed, Wanfang data were searched (up to December 2015). Randomized controlled trials recruiting patients with AG comparing CHD (alone or with western medicine (WM)) with WM were eligible. Dichotomous data were pooled to obtain relative risk (RR), with a 95% confidence interval (CI).Results: Forty-two articles including 3,874 patients were identified. CHD, used alone or with WM, had beneficial effect over WM in the improvement of clinical manifestations (RR=1.28; 95% CI 1.22-1.34) and pathological change (RR=1.42; 95% CI 1.30-1.54) for AG patients. However, the H. pylori eradication effect of CHD was not supported by the existing clinical evidence, because of the significant study heterogeneity (I2>50%) and inconsistency between the primary results and sensitivity analysis.Conclusions: CHD, if prescribed as a complementary therapy to WM, may improve the clinical manifestations and pathological change for AG patients. But its monotherapy for H. pylori eradication is not supported by enough clinical evidence.Keywords: atrophic gastritis; Helicobacter pylori; Chinese herbal decoction; meta-analysi
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