Diverse prenylated C6-C3 derivatives from the stems and branches of Illicium ternstroemioides A. C. Smith with anti-inflammatory and antiviral activities.

Fifteen unreported prenylated C6-C3 derivatives (1-15) were isolated from the stems and branches of Illicium ternstroemioides A. C. Smith, including one bis-prenylated C6-C3 derivative (1), three prenylated C6-C3 derivative-shikimic acid ester hybrids (2-4) and 11 prenylated C6-C3 monomers (5-15). The structures of compounds 1-15 were elucidated by spectroscopic analysis (UV, IR, 1D and 2D NMR, and HRESIMS). The absolute configurations of the compounds were determined using electronic circular dichroism (ECD), induced circular dichroism (ICD), and the modified Mosher's method. Among the isolates, compounds 11, 12, and 15 exhibited significant anti-inflammatory activities by inhibiting the nitric oxide with IC50 values ranging from 1.89 to 24.83 µM in lipopolysaccharide-stimulated murine RAW 264.7 macrophages and murine BV2 microglial cells; compounds 2, 3, and 7 exhibited antiviral activitives against Coxsackievirus B3 with an IC50 value of 33.3, 25.9, and 27.8 µM, respectively.

Insights to Human γD-Crystallin Unfolding by NMR Spectroscopy and Molecular Dynamics Simulations.

Human γD-crystallin (HGDC) is an abundant lens protein residing in the nucleus of the human lens. Aggregation of this and other structural proteins within the lens leads to the development of cataract. Much has been explored on the stability and aggregation of HGDC and where detailed investigation at the atomic resolution was needed, the X-ray structure was used as an initial starting conformer for molecular modeling. In this study, we implemented NMR-solution HGDC structures as starting conformers for molecular dynamics simulations to provide the missing pieces of the puzzle on the very early stages of HGDC unfolding leading up to the domain swap theories proposed by past studies. The high-resolution details of the conformational dynamics also revealed additional insights to possible early intervention for cataractogenesis.

Quercetin attenuates ischemia reperfusion injury by protecting the blood-brain barrier through Sirt1 in MCAO rats.

The purpose of the present study was to examine the protective action and mechanisms of quercetin on the blood-brain barrier (BBB) in rats subjected to transient middle cerebral artery occlusion (tMCAO) and reperfusion. Quercetin (10, 30, 50 mg/kg) was intraperitoneally administered at the onset of reperfusion. The results showed that quercetin significantly reduced cerebral infarct volume, neurological deficit, BBB permeability and ROS generation via Sirt1/Nrf2/HO-1 signaling pathway. Moreover, EX527, a selective inhibitor of Sirt1, reversed these neuroprotective effects. Our findings indicate that quercetin has neuroprotective effects against cerebral ischemia-reperfusion injury by protecting BBB through Sirt1 signaling pathway in MCAO rats.

Chitosan/Polyvinyl Alcohol/ Lauramidopropyl Betaine/2D-HOF Mixed Film with Abundant Hydrogen Bonds Acts as High Mechanical Strength Artificial Skin.

The mechanical properties of artificial skins are complicated to maintain under ensuring air permeability and antimicrobial. Thus, a series of hydrophilic antimicrobial polymer networks are prepared by crosslinking chitosan and polyvinyl alcohol with the lauramidopropyl betaine and hydrogen bond organic framework (CS/PVA/LPB/2D-HOF). The mechanical performance of the control groups and the complex are systematically evaluated to attain an artificial strength skin. The CS/PVA/LPB/2D-HOF complex exhibits strong mechanical abilities than other control groups. By analyzing the IR spectra and the morphology, the synergistic effect of hydrogen bonds between molecules and cracks significantly improves the mechanical properties of the complex. Its maximum tensile strength can reach 29 MPa, and its maximum load capacity can reach 3700 g. Notably, the composite membrane also performs an excellent antimicrobial activity. In vivo and in vitro experiments show that the hybrid membrane can promote tissue regeneration and wound healing (95％). These results may open up the opportunity for future composite material investigations in the artificial skin and tissue engineering field.

Family Medicine Academic Workforce of Medical Schools in Taiwan: A Nationwide Survey.

Little is known about family medicine academic workforce in Taiwan, and basic data on this may aid healthcare decision-makers and contribute to the limited literature. We analyzed data from 13 medical schools in Taiwan collected by the Taiwan Association of Family Medicine from June to September 2019, regarding characteristics of medical schools, and total staff, gender, age, degree, working title (adjunct/full-time), academic level, and subspecialty of each current family medicine faculty member. Total 13 medical schools in Taiwan with an undergraduate education program in family medicine, but only nine of the 13 medical schools had family medicine departments, while four still do not. A total of 116 family medicine faculty members ranging from 33-69 years. Of these, most were male (n = 85, 73.3%), with a mean age of 43.3 years. Most faculty members possessed a master's degree (n = 49, 42.2%), were academic lecturers (n = 49, 42.2%), were located in northern Taiwan (n = 79, 68.1%), and subspecialize in gerontology and geriatrics (n = 55, 47.4%) and hospice palliative care (n = 53, 45.7%). Additionally, most family medicine faculty in medical schools were adjunct faculty (n = 90, 77.6%), with only about one-fourth (n = 26, 22.4%) working full-time. Our study provides the most holistic census to date on academic family medicine faculty from all medical schools in Taiwan. The novel information can provide educational leaders, health policy managers, and decision-makers about the current developments of the family medicine departments in Taiwan's medical schools. The basic data will help formulate an effective medical school family medicine education plan and improve the establishment and development of the family medicine faculty workforce to help medical education and national health policy development in the future in Taiwan.

[Genotyping of RhD-negative blood samples diagnosed by serological tests from patients waiting for kidney transplantation].

OBJECTIVE: To compare the accuracy of serological and molecular approaches to identification of RhD-negative patients waiting for kidney transplantation. METHODS: A total of 103 RhD-negative blood samples by serological test were collected from patients waiting for kidney transplantation between January, 2006 and January, 2016. Quantitative PCR and sequencing were used to verify the results of RHD genotyping, and the false negative rates of the serological and molecular methods for RhD genotyping were compared. RESULTS: Among the 103 blood samples, true RhD negativity (with all the 10 exons missing) was found in 56 samples (54.5%), and false RhD negativity (RhD positivity with loss, repetition, or missense mutation in the 10 exons) in 47 samples (45.6%). In the 47 false RhD-negative cases, weak D was detected in 1 case (2.1%), partial D in 13 cases (27.7%), and D-elution in 33 cases (70.2%). The detection rates of RhD negativity differed significantly between the serological and molecular methods (P<0.05). CONCLUSION: Serological test is associated with a high false negative rate in detecting RhD blood group, and the use of the molecular approach has important clinical significance in accurate RhD genotyping for patients waiting for renal transplantation.

[Identification and Influence of Quorum Sensing on Anaerobic Ammonium Oxidation Process].

Anaerobic ammonium oxidation (ANAMMOX), an innovative nitrogen removal technology, has good prospects for applications. However, ANAMMOX bacteria grow slowly and are hardly accumulated in bioreactors. In this study, a UASB reactor inoculated with sludge from landfill leachate treatment plant was used for the start-up of ANAMMOX process. Besides, exogenous quorum sensing signals (DSF and AHL) were added to improve the adhesion of ANAMMOX sludge. The results showed that the UASB successfully started the ANAMMOX process within 150 days of operation. The total nitrogen removal rate reached 80% and the proportion of ANAMMOX bacteria rose to 20%. There was a low concentration of AHLs signal molecules in the ANAMMOX sludge. If the ß-position substituent group of AHL added was a carbonyl group (including 3-oxo-C6-HSL, 3-oxo-C8-HSL, 3-oxo-C10-HSL and 3-oxo-C12-HSL), the adhesion growth ability of the ANAMMOX sludge could be improved. In the case of dosing with AHL molecules without ß-position substituent groups, only C6-HSL and C12-HSL could promote the adhesion of ANAMMOX sludge. The additions of C8-HSL, C10-HSL and DSF all had negative effects on the adhesion of ANAMMOX sludge.

3-Nitro-2H-chromenes as a new class of inhibitors against thioredoxin reductase and proliferation of cancer cells.

A series of 3-nitrochromenes were designed and synthesized. These compounds showed good inhibitory activity against thioredoxin reductase (TrxR) and the proliferation of A549 cancer cells. The structure-activity relationship analysis indicates that the 3-nitrochromene scaffold is the crucial pharmacophore for achieving good inhibitory activity. The bromo-substitutions at the 6- and 8-position of 3-nitrochromene significantly increase the inhibitory activity.

Design, synthesis, and biological evaluation of curcumin analogues as multifunctional agents for the treatment of Alzheimer's disease.

A series of novel curcumin analogues were designed, synthesized, and evaluated as potential multifunctional agents for the treatment of AD. The in vitro studies showed that these compounds had better inhibitory properties against Aß aggregation than curcumin. Superior anti-oxidant properties (better than the reference compound Trolox) of these compounds were observed by the oxygen radical absorbance capacity (ORAC) method and a cell-based assay using DCFH-DA as a probe. In addition they were able to chelate metals such as iron and copper and decrease metal-induced Aß aggregation. The structure-activity relationships were discussed. The results suggested that our curcumin analogues could be selected as multifunctional agents for further investigation of AD treatment.

Impact of planarity of unfused aromatic molecules on G-quadruplex binding: learning from isaindigotone derivatives.

G-quadruplex structures are a new class of attractive targets for DNA-interactive anticancer agents. The primary building block of this structure is the G-quartet, which is composed of four coplanar guanines and serves as the major binding site for small molecules. NMR studies and molecular dynamics simulations have suggested that the planarity of G-quartet surface has been highly dynamic in solution. To better investigate how the planarity of unfused aromatic ligand impacts on its quadruplex binding properties, a variety of planarity controllable isaindigotone derivatives were designed and synthesized. The interaction of G-quadruplex DNA with these designed ligands was systematically explored using a series of biophysical studies. The FRET-melting, SPR, and CD spectroscopy results showed that reducing the planarity of their unfused aromatic core resulted in their decreased binding affinity and stabilization ability for G-quadruplex. NMR studies also suggested that these compounds could stack on the G-quartet surface. Such results are in parallel with subsequent molecular modeling studies. A detailed binding energy analysis indicated that van der Waals energy (ΔE(vdw)) and entropy (TΔS) are responsible for their decreased quadruplex binding and stabilization effect. All these results provided insight information about how quadruplex recognition could be controlled by adjusting the planarity of ligands, which shed light on further development of unfused aromatic molecules as optimal G-quadruplex binding ligands.

Inhibition of cell proliferation by quindoline derivative (SYUIQ-05) through its preferential interaction with c-myc promoter G-quadruplex.

G-Quadruplex is a special DNA secondary structure and present in many important regulatory regions in human genome, such as the telomeric end and the promoters of some oncogenes. Specially, different forms of G-quadruplexes exist in telomeric DNA and c-myc promoter and play important roles in the pathway of cell proliferation and senescence. The effects of G-quadruplex ligands for either telomeric or c-myc G-quadruplex in vitro have been widely studied, but the specificity of these effects in vivo is still unknown. In the present research, various experiments were carried out to study the effect of G-quadruplex ligand SYUIQ-05 on tumor cell lines and the mechanism of this effect. Our results showed that it preferred to bind with G-quadruplex in c-myc and had rather insignificant effect on G-quadruplex in telomere. Therefore, it is possible that this compound had its antitumor activity for cancer cells mainly through its interaction with c-myc quadruplex.

Disubstituted 2-phenyl-benzopyranopyrimidine derivatives as a new type of highly selective ligands for telomeric G-quadruplex DNA.

A series of 2-phenyl-benzopyranopyrimidine (PBPP) derivatives with alkylamino side chains were synthesized and found to be a new type of highly selective ligand to bind with telomeric G-quadruplex DNA, and their biological properties were reported for the first time. Their interactions with telomeric G-quadruplex DNA were studied with FRET melting, surface plasmon resonance, CD spectroscopy, and molecular modeling. Our results showed that the disubstituted PBPP derivatives could strongly bind to and effectively stabilize the telomeric G-quadruplex structure, and had significant selectivity for G-quadruplex over duplex DNA. In comparison, the mono substituted derivatives had much less effect on the G-quadruplex, suggesting that the disubstitution of PBPP is essential for its interaction with the G-quadruplex. Furthermore, telomerase inhibition of the PBPP derivatives and their cellular effects were studied, and compound 11b was found to be the most promising compound as a telomerase inhibitor and telomeric G-quadruplex binding ligand for further development for cancer treatment.

Syntheses and characterization of nimesulide derivatives for dual enzyme inhibitors of both cyclooxygenase-1/2 and 5-lipoxygenase.

Cyclooxygenase-1/2 (COX-1/2) and 5-lipoxygenase (5-LOX) are enzymes in two different pathways in the inflammatory process. In the present study, a variety of new nimesulide derivatives were synthesized through incorporation of a 5-LOX pharmacophore into nimesulide followed with some structural modifications, which were then characterized for dual enzyme inhibitors for these two types of enzymes. Their structure-activity relationships (SARs) were studied, and compound 20f was found to be an excellent dual enzyme inhibitor. Its binding conformation and interaction mode were studied with molecular docking experiments. Compound 20f could become a lead compound for further development for potential anti-inflammatory drugs.

Site-controlled self-assembled InAs quantum dots grown on GaAs substrates.

Atomically-flat surfaces are obtained after thin GaAsSb buffer layer growth on GaAs substrates with regular-distributed nano-holes formed after oxide desorption of the local atomic-force-microscopy anode oxidation. Different from the samples with GaAsSb buffer layers, increasing surface root-mean-square roughness is observed for the GaAs-buffered samples with increasing GaAs buffer layer thickness. The phenomenon is attributed to the enhanced adatom migration resulting from the incorporation of Sb atoms. By using the substrates with nano-holes after buffer layer growth, site-controlled self-assembled InAs quantum dots (QDs) are observed with the deposition of a below-critical-thickness InAs coverage of 1.3 monolayer (ML).

The dependence of terahertz radiation on the built-in electric field in semiconductor microstructures.

The amplitudes of terahertz radiation are measured for a series of GaAs surface intrinsic-N(+) structures with various built-in surface electric fields as the bias. As the surface field is lower than the so-called "critical electric field" related with the energy difference between the Gamma to L valley of the semiconductor, the amplitude is proportional to the product of the surface field and the number of photo-excited carriers. As the surface field exceeds the critical field, the amplitude is independent of the surface field but proportional to the product of the critical field and the number of the photo-excited carriers.