Divergent Synthesis of α-(1,3,5-Triazinylthio)-ketones and Thiazolo[3,2-][1,3,5]triazines from 1,3-Dicarbonyl compounds or Chalcones with 1,3,5-Triazine-2-thiols.

An efficient synthesis of α-(1,3,5-triazinylthio)-ketones from 1,3-dicarbonyl compounds with 1,3,5-triazine-2-thiols has been developed. The reaction proceeds through the C-C bond cleavage and C-S bond reconstruction of 1,3-dicarbonyl compounds, and β-keto esters, β-keto amides, and 1,3-diones were tolerated. In addition, the annulation of 1,3,5-triazine-2-thiols with chalcones has been achieved for the synthesis of thiazolo[3,2-][1,3,5]triazines.

Role of 7-methylxanthine in myopia prevention and control: a mini-review.

Myopia is becoming increasingly common. By 2050 around 10% of the world's population is expected to be highly myopic (<-5 diopters) and therefore particularly at risk of suffering from sight-threatening complications. Currently used myopia control treatments, such as multifocal soft contact lenses or spectacle lenses, orthokeratology, and atropine eyedrops, either do not completely arrest myopia progression or are associated with significant ocular and possibly systemic side effects.

Direct arterial puncture for hemodialysis, a neglected but simple and valuable vascular access.

Introduction: The purpose of this study is to present the prevalence and effects of direct arterial puncture (DAP) for hemodialysis patients, and to introduce optimal option for the vascular access (VA) in certain hemodialysis patients with poor condition of vascular or cardiac function in a compelling situation.

Methods: This was a cross-sectional study. Demographic characteristics and laboratory data were extracted from the health care system.

Diversity-oriented synthesis of imidazo[1,2-][1,3,5]triazine derivatives from 2-amine-[1,3,5]triazines with ketones.

An I-mediated annulation of 2-amino[1,3,5]triazines and ketones for the synthesis of imidazo[1,2-][1,3,5]triazines is presented. Electron rich, or electron poor acetophenone and heterocycle ketones, as well as propiophenone, are functionalized with 2-amino-[1,3,5]triazines. Another class of imidazo[1,2-][1,3,5]triazines tethered with an additional 1,2-dicarbonyl motif through the combination of annulation and C-H functionalization were obtained instead by changing the reaction conditions.

Impact of pulmonary hypertension on arteriovenous fistula failure of hemodialysis patients: A 10 years follow-up cohort study.

Background: Pulmonary hypertension (PH) is common in patients with end-stage renal disease (ESRD). Arteriovenous fistulas (AVF) creation may involve in the pathogenesis of PH. The aim of this study was to explore the impact of PH after AVF creation on the AVF failure rate in maintenance hemodialysis (MHD) patients.

All-trans retinoic acid increases ARPE-19 cell apoptosis activation of reactive oxygen species and endoplasmic reticulum stress pathways.

Aim: To explore the apoptosis of ARPE-19 cells after the treatment with different doses of all-trans-retinoic acid (ATRA).

Methods: ARPE-19 cells were used in the experiment. Flow cytometry assay was employed to evaluate the level of reactive oxygen species (ROS) and apoptosis.

Rescue of cognitive deficits in APP/PS1 mice by accelerating the aggregation of β-amyloid peptide.

Background: Brain amyloid deposition is one of the main pathological characteristics of Alzheimer's disease (AD). Soluble oligomers formed during the process that causes β-amyloid (Aβ) to aggregate into plaques are considered to have major neurotoxicity. Currently, drug development for the treatment of Alzheimer's disease has encountered serious difficulties.

Copper-Catalyzed Tandem Reactions of 2-Amine-[1,3,5]triazines with Nitriles.

Copper-catalyzed intermolecular annulation of 2-amine-[1,3,5]triazines and aryl nitriles for the synthesis of [1,2,4]triazolo[1,5- a][1,3,5]triazines via N-C bond formation and oxidative N-N coupling [oxidative 3 + 2 cyclization] is presented. A wide range of aryl nitriles, including electron-rich benzonitriles, electron-poor benzonitriles, 2-cyanothiophene, and 4-cyanopyridine, were all functionalized with 2-amine-[1,3,5]triazines. Furthermore, amidation of 2-amine-[1,3,5]triazines via Cu-catalyzed C-CN bond cleavage of phenylacetonitriles is also demonstrated.

Ruthenium-catalyzed synthesis of arylethyl 1,3,5-triazines from arylallyl alcohols and biguanides.

An efficient ruthenium-catalyzed synthesis of alkyl-1,3,5-triazies from arylallyl alcohols and biguanides has been developed. The reaction occurred in moderate to good yields and tolerated heterocyclic or aryl allyl alcohols containing functionalities such as alkanes, ethers, and halogens. The reaction proceeds through a one-pot sequence of transfer hydrogenation and condensation steps.

Formal total synthesis of salvianolic acid N.

An efficient synthetic pathway for the total synthesis of salvianolic acid N has been reported. The key reaction steps, the Wittig reaction for Z-stereoselectivity and an intramolecular cyclization for a seven membered ring skeleton, have been optimized to improve the synthetic feasibility and provide the best conditions in terms of yield. Moreover, a notable reaction is the reaction of the deprotected allylic group with Pd catalyst.

Effect of dopamine on bone morphogenesis protein-2 expression in human retinal pigment epithelium.

Aim: To investigate the effect of dopamine on bone morphogenesis protein-2 (BMP-2) expression in retinal pigment epithelium (RPE) cells .

Methods: ARPE-19 cells as a human RPE cell line were cultured with dopamine for different times (2, 4, 6, 8, 12, 16 and 24h) or with different concentrations (0.1, 1, 2, 5, 10, 20, and 100 µg/mL) .

2,4-Diamino-1,3,5-triazine-enabled Cu-catalyzed direct sulfonamidation of aromatic C-H bonds.

An efficient copper acetate catalyzed sulfonamidation of arenes via C-H bond activation directed by a 2,4-diamino-1,3,5-triazine chelating group under oxygen as a terminal oxidant has been developed. The reaction shows good regioselectivity and functional group tolerance, as well as providing a straightforward methodology for the preparation of ortho-monosulfonamidated arene derivatives in moderate to high yields. The sulfonamidation at the gram scale can be performed with a good yield.

Copper-Catalyzed Synthesis of Substituted 2,4-Diamino-1,3,5-triazines from 1,1-Dibromoalkenes and Biguanides.

An efficient copper-catalyzed synthesis of substituted 2,4-diamino-1,3,5-triazines from 1,1-dibromoalkenes and biguanides under mild conditions has been developed. The reaction occurred in moderate to good yields and tolerated alkyl-, heterocyclic-, or aryl-substituted 1,1-dibromoalkenes containing functionalities such as nitriles, ethers, and halogens. Monosubstituted to tetrasubstituted biguanidines also afforded the desired products.

Copper(ii) catalyzed iodine-promoted oxidative cyclization of 2-amino-1,3,5-triazines and chalcones: synthesis of aroylimidazo[1,2-a][1,3,5]triazines.

An efficient copper(ii) catalyzed iodine-promoted synthesis of aroylimidazo[1,2-a][1,3,5]triazines from 2-amino-1,3,5-triazines and chalcones under mild conditions has been developed. The reaction occurred with good yields and excellent regioselectivities, and tolerated chalcone containing functionalities such as ethers, halogens, and nitro groups. The successful application of this methodology for a gram-scale reaction indicates its potential for bulk synthesis.

Copper-catalyzed arylation of biguanide derivatives via C-N cross-coupling reactions.

An efficient copper-catalyzed cross-coupling reaction of biguanide hydrochloride derivatives with both aryl iodides and bromides under mild conditions has been developed. The reaction occurred in good yields and tolerated aryl halides containing functionalities such as nitriles, sulfonamides, ethers, and halogens. Alkyl and cyclic substituted biguanidines were also well tolerated.

Gold-catalyzed intermolecular hydroamination of allenes with sulfonamides.

A co-catalyst of (PPh3)AuCl/AgOTf for the intermolecular hydroamination of allenes with sulfonamides is shown. The reaction proceeded smoothly under mild conditions for differently substituted allenes giving N-allylic sulfonamides in good yields with high regioselectivity and E-selectivity.

Distribution of bone morphogenetic protein receptors in human scleral fibroblasts cultured in vitro and human sclera.

Aim: To investigate the distribution of bone morphogenetic protein receptors (BMPRs) in human scleral fibroblsasts (HSFs) and in human sclera.

Methods: Primary HSFs were cultured in vitro. The mRNA levels of BMP-2 and BMPRs in HSFs were assayed by reverse transcription-polymerase chain reaction (RT-PCR).

Characteristics of the macula in amblyopic eyes by optical coherence tomography.

Aim: To test the hypothesis that amblyopic neuroretina may have an altered thickness when compared to the normal.

Methods: Twenty-five amblyopic, young patients between the ages of 7 and 11 years old were studied. The interested neuroretina areas are defined into 10 sub-regions according to superior-inferior, nasal-temoral, and peri-para axis, which cross the fovela structure.

Effects of 7-methylxanthine on form-deprivation myopia in pigmented rabbits.

Aim: To determine the effect of 7-methylxanthine (7-MX) on the posterior sclera of form-deprivation myopia (FDM) in pigmented rabbits.

Methods: Sixteen pigmented rabbits were monocularly deprived (MD) by suturing the right eyelids after natural eye opening (ten-day old) for a period of 30 days. Two groups of pigmented rabbits were fed either 7-MX (30 mg per kg body weight; n=8) or vehicle control (saline equal volume with 7-MX; n=8).

Gold-catalyzed oxidation of arylallenes: Synthesis of quinoxalines and benzimidazoles.

A gold-catalyzed oxidation of arylallenes to form α-diketones and aldehydes in good yields is presented. Further directed synthesis of quinoxalines and benzimidazoles, via the condensation of the resulting α-diketones and aldehydes with benzene-1,2-diamine, was achieved in high yields.

Expression of adenosine receptors in human retinal pigment epithelium cells in vitro.

Background: Adenosine receptors (ADORs) have been reported to play a role in experimental myopia. This study aimed to determine the distribution of ADORs in human retinal pigment epithelium (RPE) cells cultured in vitro.

Methods: Human RPE cells (cell line D407) were cultured in vitro.

Platinum-catalyzed hydrative cyclization of 1,6-diynes for the synthesis of 3,5-substituted conjugated cyclohexenones.

We have developed a Pt(COD)Cl(2)-catalyzed hydrative cyclization of 1,6-diynes leading to the formation of functionalized cyclohexenones in good yields.

Difference of gene expression between the central and the peripheral epithelia of the bovine lens.

Background: Equatorial lens epithelial cells proliferate and differentiate into fiber cells throughout life, while central lens epithelial cells proliferate little and do not form fiber cells. This study aimed to investigate the differences in gene expression between the central and the peripheral epithelial cells of the bovine lens.

Methods: Lens epithelia were dissected into central ( View Article and Find Full Text PDF

Gold-catalyzed addition of sulfonic acids to alkynes to form vinyl sulfonates.

In the presence of a catalytic amount of (Ph3P)AuNO3 and phthalimide, the addition of toluenesulfonic acid or methanesulfonic acid to alkynes has been shown to proceed and gives vinyl tosylates and vinyl mesylates in good yields and regioselectivity.

Gold-catalyzed hydroalkoxylation of alkoxyallenes.

We report synthesis of allylic acetals via gold-catalyzed hydroalkoxylation of alkoxyallenes with alcohols containing primary and secondary alcohols in good to excellent yields under mild condition.