2,839 research outputs found
Ruthenium-oxo and -tosylimido porphyrin complexes for epoxidation and aziridination of alkenes
Dioxoruthenium(VI) porphyrins including those containing chiral porphyrinato ligands can be readily prepared by oxidation of [Ru 11(Por)(CO)(MeOH)] with PhIO or metachloroperoxybenzoic acid. Similar reactions with PhINTs gave [Ru VI(Por)(NTs) 2] isolated as air stable solids at room temperature. The [Ru VI(Por)O 2] complexes are competent oxidants for epoxidation of alkenes with high selectivities. Enantioselective epoxidation of alkenes giving the corresponding organic epoxides with moderate to good enantioselectivites have also been achieved using chiral [Ru VI(D 4-Por)O 2] [D 4-H 2Por= 5,10,15,20-tetrakis-(IS,4R,5R,8S-1,2,3,4,5,6,7,8-octahydro-1,4:5,8- dimethanoanthracen-9-yl)porphyrin] and [Ru VI(D 2-Por)O 2] complexes. The mechanism of alkene epoxidation by [Ru VI(Por)O 2] has been examined. Procedures for catalytic epoxidation of alkenes using ruthenium porphyrin catalysts has also been developed. [Ru VI(Por)(NTs) 2] was found to undergo aziridination of alkenes and amidation of alkanes in organic solvents at room temperature. ©1999 IUPAC.published_or_final_versio
Ruthenium nanoparticles supported on hydroxyapatite as an efficient and recyclable catalyst for cis-dihydroxylation and oxidative cleavage of alkenes
Impregnation of hydroxyapatite with colloidal ruthenium results in the formation of a catalyst that effects cis-dihydroxylation and oxidative cleavage of alkenes to their respective cis-1,2-diols and carbonyl products in good to excellent yields (see scheme). The supported ruthenium catalyst can be easily recycled and reused for consecutive reaction runs without significant deterioration of the catalytic activities. R1, R2 = H, alkyl, aryl.postprin
Compare HIV/syphilis infections between age groups and explore associated factors of HIV/ syphilis co-infections among men who have sex with men in Shenzhen, China, from 2009 to 2017
The aim of this study is to assess the HIV/syphilis epidemic among men who have sex with men (MSM) aged <50 years and ≥ 50 years in Shenzhen, and explore the associated factors of HIV/syphilis co-infections among MSM in Shenzhen, in order to help prevention and intervention programs determine their target sub-group. A serial cross-sectional study was conducted on MSM in Shenzhen city, China from 2009 to 2017. A questionnaire was used to collect demographic characteristics, history of HIV testing, history of blood donation and sexual behaviors. 5 ml of venous blood were collected for syphilis and HIV tests. The overall prevalence of HIV, syphilis, HIV/syphilis co-infection was 9.40%, 18.97%, and 4.91%, respectively. The prevalence of HIV (15.26%), syphilis (27.71%), HIV/syphilis co-infection (9.24%) in aged ≥ 50 years MSM was significantly higher than aged <50 years MSM (9.15%, 18.59% and 4.72%, respectively). The following factors were found to be significantly associated with HIV/syphilis co-infections (P<0.05): age≥50 years (OR = 1.78, 95% CI = 1.10–2.87), high school or lower (OR = 1.49, 95% CI = 1.10–2.01), monthly income ≤436.2 USD (OR = 1.74, 95% CI = 1.25–2.42), monthly income 436.4–727.2 USD (OR = 1.46, 95% CI = 1.05–2.03), ≥2 anal sex partners in the past 6 months (OR = 1.59, 95% CI = 1.02–2.49), ≥2 oral sex partners in the past 6 months (OR = 1.60, 95% CI = 1.08–2.36), inconsistent condom use during anal sex in the past 6 months (OR = 1.50, 95% CI = 1.11–2.03). We found that aged <50 years and ≥50 years MSM in Shenzhen had a high prevalence of HIV/syphilis infection in a period from 2009 to 2017. Age-specific sexually transmitted diseases education, prevention, and intervention programs for aged ≥50 years MSM should be implemented urgently and integrated interventions of both HIV and syphilis infections on MSM are needed in the future
Water extract of Rheum officinale Baill. induces apoptosis in human lung adenocarcinoma A549 and human breast cancer MCF-7 cell lines
Author name used in this publication: De-Jian GuoAuthor name used in this publication: Peter Hoi-Fu Yu2009-2010 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe
Effect of Multifactorial Treatment Targets and Relative Importance of Hemoglobin A1c, Blood Pressure, and Low‐Density Lipoprotein‐Cholesterol on Cardiovascular Diseases in Chinese Primary Care Patients With Type 2 Diabetes Mellitus: A Population‐Based Retrospective Cohort Study
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Prediction of new onset of end stage renal disease in Chinese patients with type 2 diabetes mellitus – a population-based retrospective cohort study
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Progenitors for the corneal endothelium and trabecular meshwork: a potential source for personalized stem cell therapy in corneal endothelial diseases and glaucoma
Several adult stem cell types have been found in different parts of the eye, including the corneal epithelium, conjunctiva, and retina. In addition to these, there have been accumulating evidence that some stem-like cells reside in the transition area between the peripheral corneal endothelium (CE) and the anterior nonfiltering portion of the trabecular meshwork (TM), which is known as the Schwalbe's Ring region. These stem/progenitor cells may supply new cells for the CE and TM. In fact, the CE and TM share certain similarities in terms of their embryonic origin and proliferative capacity in vivo. In this paper, we discuss the putative stem cell source which has the potential for replacement of lost and nonfunctional cells in CE diseases and glaucoma. The future development of personalized stem cell therapies for the CE and TM may reduce the requirement of corneal grafts and surgical treatments in glaucoma.published_or_final_versio
Age-specific associations between Systolic Blood Pressure and Cardiovascular Disease: A 10-years diabetes cohort study
Abstract:
Background
The relationship between systolic blood pressure (SBP) and cardiovascular disease (CVD) among patients with diabetes mellitus remains unclear. The study aimed to explore age‐specific associations between SBP and CVD.
Methods and Results:
A population‐based retrospective cohort study was conducted on 180 492 Chinese adults with type 2 diabetes mellitus in 2008–2010, with follow‐up to 2017. Age‐specific associations (<50, 50–59, 60–69, and 70–79 years) between the average SBP in the previous 2 years and CVD risk were assessed by adjusted Cox proportional hazards regression with age‐specific regression dilution ratios and patient characteristics stratified by subgroups. During a median follow‐up of 9.3 years (1.5 million person‐years), 32 545 patients developed a CVD, with an incidence rate of 23.4 per 1000 person‐years. A positive and log‐linear association between SBP and CVD risk was observed among the 4 age groups without evidence of a threshold down to 120 mm Hg, but the magnitude of SBP effect on CVD attenuated with increased age. The CVD risk in the age group <50 years was ≈22% higher than the age group 70 to 79 years (hazard ratio [HR], 1.33 [95% CI, 1.26–1.41] versus HR, 1.09 [95% CI, 1.07–1.11]). Each 10‐mm Hg higher SBP was associated with 12% (HR, 1.12 [95% CI, 1.10–1.13]), 11% (HR, 1.11 [95% CI, 1.10–1.13]), and 20% (HR, 1.20 [95% CI, 1.17–1.22]) higher risk of all composite CVD events, individual CVD, and CVD mortality, respectively.
Conclusions:
There is a significant log‐linear relationship between baseline SBP and the risk of CVD among patients with diabetes mellitus in China. The risk increases from an SBP of 120 mm Hg onward. Age influences this relationship significantly, with younger patients (<50 years) having a greater risk of CVD for a similar rise in SBP as compared with those who are older. These findings suggest that differential target blood pressures stratified by age maybe usefu
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