Search results for "gate"
showing 10 items of 1811 documents
Hydrogels for potential colon drug release by thiol-ene conjugate addition of a new inulin derivative.
2008
Inulin was chosen as a starting polymer for biocompatible, pH-sensitive and biodegradable hydrogels. Three INUDVSA-TT hydrogels were obtained by crosslinking inulin derivatives with trimethylolpropane tris(3-mercaptopropionate) under varying conditions. The resulting hydrogels were cell compatible, as demonstrated by MTS and trypan blue exclusion assays acting on Caco-2 cells, and were biodegraded by inulinase and esterase, thus suggesting their use as colonic drug delivery systems. 2-Methoxyestradiol, an anti-cancer drug, was soaked in INUDVSA-TT hydrogels and its in vitro release and apoptotic effect on Caco-2 cells were evaluated.
Asymmetric Conjugate Addition of Malonate Esters to α,β-UnsaturatedN-Sulfonyl Imines: An Expeditious Route to Chiral δ-Aminoesters and Piperidones
2013
The asymmetric conjugate addition of malonate esters to α,β-unsaturated N-sulfonyl imines is catalyzed by PyBOX/La(OTf)3 complexes in the presence of 4 Å MS. The reaction gives the corresponding E enamines bearing a stereogenic center at the allylic position with good yields and enantiomeric ratios up to 97:3. This reaction provides a synthetic entry to chiral δ-aminoesters and piperidones.
ChemInform Abstract: Asymmetric Conjugate Addition of Malonate Esters to α,β-Unsaturated N-Sulfonyl Imines: An Expeditious Route to Chiral δ-Aminoest…
2014
The asymmetric conjugate addition of malonate esters to α,β-unsaturated N-sulfonyl imines is catalyzed by PyBOX/La(OTf)3 complexes in the presence of 4 A MS. The reaction gives the corresponding E enamines bearing a stereogenic center at the allylic position with good yields and enantiomeric ratios up to 97:3. This reaction provides a synthetic entry to chiral δ-aminoesters and piperidones.
Market efficiency and the long-memory of supply and demand: is price impact variable and permanent or fixed and temporary?
2016
In this comment we discuss the problem of reconciling the linear efficiency of price returns with the long-memory of supply and demand. We present new evidence that shows that efficiency is maintained by a liquidity imbalance that co-moves with the imbalance of buyer vs. seller initiated transactions. For example, during a period where there is an excess of buyer initiated transactions, there is also more liquidity for buy orders than sell orders, so that buy orders generate smaller and less frequent price responses than sell orders. At the moment a buy order is placed the transaction sign imbalance tends to dominate, generating a price impact. However, the liquidity imbalance rapidly incre…
Amphiphilic Polyphenylene Dendron Conjugates for Surface Remodeling of Adenovirus 5
2020
Abstract Amphiphilic surface groups play an important role in many biological processes. The synthesis of amphiphilic polyphenylene dendrimer branches (dendrons), providing alternating hydrophilic and lipophilic surface groups and one reactive ethynyl group at the core is reported. The amphiphilic surface groups serve as biorecognition units that bind to the surface of adenovirus 5 (Ad5), which is a common vector in gene therapy. The Ad5/dendron complexes showed high gene transduction efficiencies in coxsackie‐adenovirus receptor (CAR)‐negative cells. Moreover, the dendrons offer incorporation of new functions at the dendron core by in situ post‐modifications, even when bound to the Ad5 sur…
Krūts vēža molekulāro surogātapakštipu klīniski morfoloģiskais raksturojums sievietēm Latvijā un to saistība ar ķirurģiskās ārstēšanas veida izvēli u…
2015
Elektroniskā versija nesatur pielikumus
Ethical challenges involved in obtaining consent for research from patients hospitalized in the intensive care unit
2017
International audience; Clinical research remains a vital contributor to medical knowledge, and is an established and integral part of the practice of medicine worldwide. Respect for patient autonomy and ethical principles dictate that informed consent must be obtained from subjects before they can be enrolled into clinical research, yet these conditions may be difficult to apply in real practice in the intensive care unit (ICU). A number of factors serve to complexify the consent process in critically ill patients, notably decisional incapacity of the patient due to illness or sedation. Obtaining consent for research from a designated proxy or family member, commonly termed a "surrogate de…
Towards a fully synthetic MUC1-based anticancer vaccine: efficient conjugation of glycopeptides with mono-, di-, and tetravalent lipopeptides using c…
2011
Abstract The membrane-bound tumor-associated glycoprotein MUC1 is aberrantly glycosylated in cancer cells compared with normal cells, and is therefore considered an attractive target for cancer immunotherapy. However, tumor-associated glycopeptides from MUC1 do not elicit a sufficiently robust immune response. Therefore, antitumor vaccines were developed, which consist of MUC1 glycopeptides as the B epitopes and immune-stimulating toll-like receptor 2 (TLR 2) lipopeptide ligands. These fully synthetic vaccine candidates were prepared by solid-phase synthesis of the MUC1 glycopeptides. The Pam(3) Cys lipopeptide, also synthesized on solid-phase, was C-terminally coupled to oligovalent lysine…
Synthesis and biological evaluation of a novel MUC1 glycopeptide conjugate vaccine candidate comprising a 4’-deoxy-4’-fluoro-Thomsen–Friedenreich epi…
2015
The development of selective anticancer vaccines that provide enhanced protection against tumor recurrence and metastasis has been the subject of intense research in the scientific community. The tumor-associated glycoprotein MUC1 represents a well-established target for cancer immunotherapy and has been used for the construction of various synthetic vaccine candidates. However, many of these vaccine prototypes suffer from an inherent low immunogenicity and are susceptible to rapid in vivo degradation. To overcome these drawbacks, novel fluorinated MUC1 glycopeptide-BSA/TTox conjugate vaccines have been prepared. Immunization of mice with the 4’F-TF-MUC1-TTox conjugate resulted in strong im…
Enantioselective Synthesis of Pyrrolizidinone Scaffolds through Multiple-Relay Catalysis
2020
A triple-tandem protocol for the synthesis of the pyrrolizidinone skeleton has been devised. It involves a cross metathesis-intramolecular aza-Michael reaction-intramolecular Michael addition tandem sequence, starting from N-pentenyl-4-oxo-2-alkenamides and conjugated ketones. In the presence of two cooperative catalysts, namely the second-generation Hoveyda-Grubbs catalyst and (R)-TRIP-derived BINOL phosphoric acid, this multiple-relay catalytic process takes place in good yields and outstanding levels of diastero- and enantioselectivity with the simultaneous generation of three contiguous stereocenters.