Helical polyisocyanide-based macroporous organic catalysts for asymmetric Michael addition with high efficiency and stereoselectivity.

Porous materials have attracted interest due to their high specific surface area and rich functionality. Immobilizing organocatalysts onto porous polymers not only boosts enantioselectivity but also improves the reaction rates. In this work, a series of porous polymers C-poly-3s with rigid polyisocyanide-carrying secondary amine pendants as building blocks were successfully prepared.

Precise Synthesis of Optically Active and Thermo-degradable Poly(trifluoromethyl methylene) with Circularly Polarized Luminescence.

Developing high performance and environment-friendly fluoropolymers is greatly desired. In this work, we found that 2-diazo-1,1,1-trifluoroethane can be polymerized by air-stable alkyne-palladium(II) catalysts following a living polymerization mechanism, affording a fluoropolymer, poly(trifluoromethyl methylene) in high yield with controlled molar mass and low dispersity. This polymer bears trifluoromethyl on every main chain atom and thus has good resistance to chemical corrosion, high hydrophobicity, and excellent dielectric constant with low dielectric loss.

Controlled Synthesis of Cyclic-Helical Polymers with Circularly Polarized Luminescence.

Cyclic polymers attract attention because of their endless structure and unique properties, which differ from the linear analogs. However, the synthesis of cyclic polymers is difficult and prohibits their functions and applications. In this study, we reported chiral cyclic Pd -catalysts that initiate a living ring-expansion polymerization of isocyanides, yielding a single-handed cyclic-helical poly(phenyl isocyanide), with predictable molecular weight (M ) and low dispersity (M /M ), in good yield.

Precise fabrication of porous polymer frameworks using rigid polyisocyanides as building blocks: from structural regulation to efficient iodine capture.

Porous materials have recently attracted much attention owing to their fascinating structures and broad applications. Moreover, exploring novel porous polymers affording the efficient capture of iodine is of significant interest. In contrast to the reported porous polymers fabricated with small molecular blocks, we herein report the preparation of porous polymer frameworks using rigid polyisocyanides as building blocks.

Precise Synthesis of π-Conjugated Block Copolymers and Polymerization-Induced Chiral Self-Assembly toward Helical Nanofibers with Circularly Polarized Luminescence.

Precise synthesis and efficient self-assembly of semiconducting polymers are of great interest. Herein, we report the controlled synthesis of π-conjugated poly(phenyl isocyanide)--poly(phenyleneethylene) (PPI--PPE) copolymers via chain extension of ethynyl 4-iodobenzene initiated by Pd(II)-terminated helical poly(phenyl isocyanide) (PPI). The in-situ-generated block copolymers self-assembled into various supramolecular architectures depending on the PPE length.

Self-Assembly of a Bilayer 2D Supramolecular Organic Framework in Water.

Accurate control of the layer number of orderly stacked 2D polymers has been an unsettled challenge in self-assembly. Herein we describe the fabrication of a bilayer 2D supramolecular organic framework from a monolayer 2D supramolecular organic framework in water by utilizing the cooperative coordination of a rod-like bipyridine ligands to zinc porphyrin subunits of the monolayer network. The monolayer supramolecular framework is prepared from the co-assembly of an octacationic zinc porphyrin monomer and cucurbit[8]uril (CB[8]) in water through CB[8]-encapsulation-promoted dimerization of 4-phenylpyridiunium subunits that the zinc porphyrin monomer bear.

Relationship Between Gene Polymorphism of Methylenetetrahydrofolate Reductase C677T and Left Ventricular Hypertrophy in Chinese Patients with Chronic Kidney Disease.

Objective: This study aimed to investigate the relationship between the gene polymorphism of methylenetetrahydrofolate reductase (MTHFR) C677T and left ventricular hypertrophy (LVH) in patients with chronic kidney disease (CKD).

Methods: A total of 763 Chinese patients with CKD undergoing genetic testing were included in the study. The association between the gene polymorphism of MTHFR C677T and echocardiographic parameters was analyzed through univariate and multivariate analyses.

Selective Synthesis of Single-Handed Helical Polymers from Achiral Monomer and a Mechanism Study on Helix-Sense-Selective Polymerization.

Inspired by the exquisite helices in Nature, fabrication of helical materials with controlled handedness has attracted considerable attention. Herein, we report on precis synthesis of single left- and right-handed helical polyisocyanides through living polymerization of achiral monomers using chiral palladium catalysts under helix-sense-selective manner. Mechanism study revealed that the yielded helices with opposite handedness showed different activity of the living chain end.

Controlled Synthesis of Shell Cross-Linked Helical Poly(phenylborate isocyanide) Nanoparticles with HO/Redox Dual Responsiveness and Their Application in Antitumor Drug Delivery.

To mimic the helical structure and function of biopolymers, shell cross-linked nanoparticle (P4) composed of left-handed helical poly(phenylborate isocyanide) in core and hydrophilic polyisocyanide in shell was prepared. The phenylborate in the core and the disulfide bonds in the cross-linkage render the nanoparticle with excellent dual stimuli-responsiveness to glutathione (GSH) and HO. Nevertheless, it has good stability in normal physiological conditions.

Crystallization-Driven Asymmetric Helical Assembly of Conjugated Block Copolymers and the Aggregation Induced White-light Emission and Circularly Polarized Luminescence.

Controlling the self-assembly morphology of π-conjugated block copolymer is of great interesting. Herein, amphiphilic poly(3-hexylthiophene)-block-poly(phenyl isocyanide)s (P3HT-b-PPI) copolymers composed of π-conjugated P3HT and optically active helical PPI segments were readily prepared. Taking advantage of the crystallizable nature of P3HT and the chirality of the helical PPI segment, crystallization-driven asymmetric self-assembly (CDASA) of the block copolymers lead to the formation of single-handed helical nanofibers with controlled length, narrow dispersity, and well-defined helicity.

A Facile Synthetic Route to Amphiphilic Poly(-Phenylene Ethynylene) and Poly(-Phenylene Ethynylene)--Polyisocyanide Using a Single Catalyst.

An optically active, amphiphilic -phenylene ethynylene (-PE) bearing a chiral amide pendant was designed and synthesized. Living polymerization of -PE using alkyne-Pd(II) as the initiator afforded well-defined poly(-phenylene ethynylene) (-PPE). These -PPEs were found to have a stable helical conformation in THF, 1,4-dioxane, and CH₃CN and showed split Cotton effects over the range of 245⁻400 nm.

Kidney injury molecule-1 expression predicts structural damage and outcome in histological acute tubular injury.

Background: A few studies have shown that urinary kidney injury molecule-1 (uKIM-1) levels are increased in acute kidney injury (AKI); however, the correlation between uKIM-1 and histological tubular injury, which is considered to be the gold standard for evaluating renal damage and predicting prognosis, is still unclear. We performed this study to determine whether the predicted value of uKIM-1 is correlated with renal KIM-1 (tKIM-1) expression and tissue damage in AKI patients.

Methods: This retrospective study recruited 14 healthy individuals and 27 biopsy-proven acute tubular injury (ATI) patients.

Synthesis of Redox-Responsive Core Cross-Linked Micelles Carrying Optically Active Helical Poly(phenyl isocyanide) Arms and Their Applications in Drug Delivery.

In this manuscript, we designed and synthesized three core cross-linked micelles (-, -, and -) with redox-responsive disulfide bonds in the core and carrying optically active helical polyisocyanide arms. Their arms were different in the helicity of the main chain and the chirality of the side groups. These micelles showed excellent redox-responsiveness to reducing agent.

Oxidative stress in 5/6 nephrectomized rat model: effect of alpha-lipoic acid.

Alpha-lipoic acid (ALA) is a powerful antioxidant, and its effect in ameliorating complications of diabetes mellitus has been widely documented. The aim of this study was to investigate the role of ALA in the disease progression of remnant kidneys (RK). Systolic blood pressure (SBp), hemoglobin, renal function, kidney malondialdehyde (MDA), glutathione (GSH), vitamin E (Vit E) concentrations, p65 nuclear factor (NF)-κB activity, and macrophage infiltration were analyzed in sham and RK rats supplemented with ALA (100 mg/kg body weight, i.

The balance of beneficial and deleterious effects of hypoxia-inducible factor activation by prolyl hydroxylase inhibitor in rat remnant kidney depends on the timing of administration.

Background: Chronic hypoxia in the kidney has been suggested as a final common pathway in the progression of chronic kidney disease (CKD) leading to eventual kidney failure. Hypoxia-inducible factor (HIF) activation might offer a promising approach to the protection of hypoxic tissues, but the effect of HIF activation on CKD is still controversial. In this study, we investigated whether HIF activation had a beneficial or deleterious effect on CKD in the rat remnant kidney (RK) model.

The relationship between the level of serum creatinine, modified diet and renal disease formula, Cockcroft-Gault formula, and renal tubulointerstitial lesion.

Objective: This study investigated the relationship between the levels of serum creatinine (SCr), the estimated glomerular filtration rate (eGFR), and the degree of tubulointerstitial injury.

Methods: A total of 511 patients of Zhongshan hospital in China were hospitalized due to physical abnormalities and diagnosed with kidney disease by renal biopsy. The clinical and pathological data were retrospectively analyzed.

Diverse effects of ischemic pretreatments on the long-term renal damage induced by ischemia-reperfusion.

Background/aims: The role of ischemic pretreatment in long-term changes after renal ischemia-reperfusion (I/R) injury remains unknown. In this study, we mainly aimed to investigate the effect of ischemic pretreatments with different durations on the development of tubulointerstitial fibrosis and functional impairment following acute renal I/R.

Methods: We established a rat model of renal warm I/R, clamping both pedicles for 40 min followed by reperfusion; the experiment was followed up for 10 weeks.

Immunosuppressive effects of demethylzeylasteral in a rat kidney transplantation model.

In this study, we examined the immunosuppressive activity of demethylzeylasteral (T-96), isolated from the traditional Chinese herbal medicine, Tripterygium wilfordii Hook f. Its immunosuppressive effect was investigated using mouse splenocytes in vitro, and in an in vivo rat kidney transplant model. T-96 inhibited mouse splenocyte proliferation in a dose dependent manner.

The role of nuclear factor-kappaB in rats of radiocontrast-media-induced nephropathy.

This study was undertaken to examine the possible role of the DNA-binding activity of nuclear factor-kappa B (NF-kappaB) in rat of radiocontrast-media-induced nephropathy (RCIN) and to explore the characteristic of RCIN in rats and the role of NF-kappaB in its occurrence. Forty-eight adult male Sprague-Dawley (SD) rats were randomly divided into Groups A-D. Rats of Groups A and B were intravenously injected with NG-nitro-L-arginine methyl ester (L-NAME) (10 mg/kg) and indomethacin (10 mg/kg), respectively.

Clinical value of urinary kidney biomarkers for estimation of renal impairment in elderly Chinese with essential hypertension.

The purpose of this work was to observe the excretion of specific types of urinary proteins and urinary enzymes in elderly essential hypertension patients, for early detection and targeted treatment of hypertensive nephropathy in the elderly. A total of 120 elderly essential hypertensive patients and 38 healthy elderly volunteers were involved. The urinary excretion rate of retinal-binding protein (RBP), transferrin (Tf), albumin (Alb), and urinary enzyme N-acetyl-beta-D-glucosaminidase (NAG) activity were determined.

Effects of tripterine on mRNA expression of TGF-beta1 and collagen IV expression in BW F1 mice.

Tripterine is a chemical isolated from a traditional Chinese herb which had been testified for its anti-inflammatory and immunosuppressive activities in a previous study. However, little is known about the effects and mechanism of action of Tripterine on treating lupus nephritis. In the present study we investigated the effect of Tripterine on the F1 hybrids of New Zealand Black (NZB) and New Zealand White (NZW) mice which functioned as a model of human systemic lupus erythematosus (BW F1 mice) and evaluated the possible mechanism implicated in the mRNA expression of TGF-beta1 and collagen IV expression of the BW F1 mice kidney tissue.

AP-1 complexes mediate oxidized LDL-induced overproduction of TGF-beta(1) in rat mesangial cells.

Oxidized Low Density Lipoprotein (Ox-LDL)-induced overproduction of the prosclerotic cytokine transforming growth factor-beta1 (TGF-beta(1)) has been implicated in the pathogenesis of renal fibrosis and sclerosis. Because Ox-LDL increases TGF-beta(1) mRNA levels in rat mesangial cells, our investigation was designed to characterize these effects on the rat TGF-beta(1) promoter activity. We transfected luciferase reporter gene constructs containing TGF-beta(1) 5'-flanking sequence (from -1550 to +57 bp) into mesangial cells.