2,507 research outputs found
Influence of vitamin D supplementation on plasma lipid profiles: A meta-analysis of randomized controlled trials
Observational studies have shown that low serum levels of vitamin D have been associated with an atherogenic lipid profile. However, the intervention studies gave divergent results. We conducted a meta-analysis of randomized controlled trials that evaluated the effects of vitamin D supplementation on blood lipids. A systematic literature search was conducted via MEDLINE, Cochrane library, and EMBASE for randomized controlled clinical trials assessing the effects of vitamin D supplementation on lipids. The mean change in total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG) from baseline was treated as a continuous variable. In all, 12 clinical trials consisting of 1346 participants were included in the analysis. The pooled estimate of effect for vitamin D supplementation on LDL-C was 3.23 mg/dl (95% confidence interval, 0.55 to 5.90 mg/dl). No statistically significant effects for vitamin D supplementation were observed for TC, HDL-C and TG (differences in means were 1.52 mg/dl (-1.42 to 4.46 mg/dl), -0.14 mg/dl (-0.99 to 0.71 mg/dl) and -1.92 mg/dl (-7.72 to 3.88 mg/dl) respectively). The lipid modulating effects of vitamin D supplementation should be further investigated though large-scale, randomized trials with adequate doses which can effectively elevated the active form of vitamin D in plasma and with proper population which has hyperlipemia as an inclusion criterion
Emodin enhances osteogenesis and inhibits adipogenesis
BACKGROUND: It has been suggested that the formation of osteoblasts in bone marrow is closely associated with adipogenesis, and the balance between osteogenesis and adipogenesis differentiation of MSCs (mesenchymal stem cells) is disrupted in osteoporosis. In order to improve the treatment of osteoporosis, available agents with roles of regulating the balance is highly desirable. Emodin is a natural anthraquinone derivative extracted from Chinese herbs, which have been used to treat bone diseases for thousands of years. However, the underlying molecular mechanisms of emodin in modulating osteogenesis and adipogenesis remain poorly understood. METHODS: The molecular mechanisms of emodin on the processes of osteogenesis and adipogenesis in ovariectomized mouse and BMSCs (bone marrow mesenchymal stem cells) have been studied. We have analyzed the effects of emodin in vivo and in vitro. Female ICR mice were assigned to three groups: sham group, ovariectomy group, emodin group. Efficacy was evaluated by H&E, immunohistochemical assay and Micro-CT. In vitro, we analyze the effect of emodin—at concentrations between 0.1 μM and 10 μM-on the processes of inducing osteogenesis and inhibiting adipogenesis in BMSCs by ALP, Oil red O staining, real time RT-PCR and western blot. RESULTS: As our experiment shows that emodin could increase the number of osteoblast, BMD (bone mineral density), BV/TV (trabecular bone volume fraction), Tb.N (trabecular number) and Conn.D (connectivity density) of OVX (ovariectomized) mice and decrease the bone marrow fat tissue and adipocytes. The genes and proteins expression of osteogenesis markers, such as Runx2, osterix, collagen type I, osteocalcin, or ALP were up-regulated. While, the genes and proteins involved in adipogenesis, PPARγ, C/EBPα and ap2 were down-regulated. CONCLUSION: It proves that emodin inhibits adipocyte differentiation and enhances osteoblast differentiation from BMSCs
Vision Learners Meet Web Image-Text Pairs
Most recent self-supervised learning methods are pre-trained on the
well-curated ImageNet-1K dataset. In this work, given the excellent scalability
of web data, we consider self-supervised pre-training on noisy web sourced
image-text paired data. First, we conduct a benchmark study of representative
self-supervised pre-training methods on large-scale web data in a like-for-like
setting. We compare a range of methods, including single-modal ones that use
masked training objectives and multi-modal ones that use image-text
constrastive training. We observe that existing multi-modal methods do not
outperform their single-modal counterparts on vision transfer learning tasks.
We derive an information-theoretical view to explain these benchmark results,
which provides insight into how to design a novel vision learner. Inspired by
this insight, we present a new visual representation pre-training method,
MUlti-modal Generator~(MUG), that learns from scalable web sourced image-text
data. MUG achieves state-of-the-art transfer performance on a variety of tasks
and demonstrates promising scaling properties. Pre-trained models and code will
be made public upon acceptance.Comment: Project page: https://bzhao.me/MUG
Reaction And Characterization Of Low-Temperature Effect Of Transition Nanostructure Metal Codoped Scr Catalyst
Typical p-type semiconductor MnO codoped with n-type semiconductors such as CeO2 and V2O5 was reported to achieve high efficiency in catalytic NO removal by NH3. In this paper, we present novel Mn-Ce codoped V2O5/TiO2 catalyst which exhibited an excellent NO conversion efficiency of 90% at 140°C. By using this codoped catalyst, the best low-temperature activity was greatly decreased when compared with single Mn- or Ce-doped catalyst. According to the characterization results from BET, XRD, and XPS, the codoped catalyst was composed of both CeO2 and amorphous Mn. The electron circulation formed between doping elements is believed to promote the electron transfer, which may be one of the reasons for excellent low-temperature denitration performance
Liver Transplantation in China
Liver transplantation has been developed in Mainland China for about 40 years, from clinical trials to maturity. Its number has become the second in the world, its quality is also in line with the international level, and the source of donors has gradually transitioned to donation after citizen’s death (DCD). This chapter is aimed to elaborate the liver transplant work in China from the history and current status of liver transplantation, the main operating methods, major indications, donor maintenance and donor quality assessment, postoperative major complications, and application of immunosuppressive agents to the postoperative follow-up. Liver transplantation is a meaningful and challenging work currently in China; all the Chinese transplant surgeons and scholars are devoting themselves to this work in order to give more effective help to the patients
Reaction and Characterization of Low-Temperature Effect of Transition Nanostructure Metal Codoped SCR Catalyst
Typical p-type semiconductor MnOx codoped with n-type semiconductors such as CeO2 and V2O5 was reported to achieve high efficiency in catalytic NOx removal by NH3. In this paper, we present novel Mn-Ce codoped V2O5/TiO2 catalyst which exhibited an excellent NO conversion efficiency of 90% at 140°C. By using this codoped catalyst, the best low-temperature activity was greatly decreased when compared with single Mn- or Ce-doped catalyst. According to the characterization results from BET, XRD, and XPS, the codoped catalyst was composed of both CeO2 and amorphous Mn. The electron circulation formed between doping elements is believed to promote the electron transfer, which may be one of the reasons for excellent low-temperature denitration performance
Deficiency of IKKβ in neurons ameliorates Alzheimer's disease pathology in APP- and tau-transgenic mice
In Alzheimer's disease (AD) brain, inflammatory activation regulates protein levels of amyloid-β-peptide (Aβ) and phosphorylated tau (p-tau), as well as neurodegeneration; however, the regulatory mechanisms remain unclear. We constructed
APP- and tau-transgenic AD mice with deletion of IKKβ specifically in neurons,
and observed that IKKβ deficiency reduced cerebral Aβ and p-tau, and modified inflammatory activation in both AD mice. However, neuronal deficiency of
IKKβ decreased apoptosis and maintained synaptic proteins (e.g., PSD-95 and
Munc18-1) in the brain and improved cognitive function only in APP-transgenic
mice, but not in tau-transgenic mice. Additionally, IKKβ deficiency decreased
BACE1 protein and activity in APP-transgenic mouse brain and cultured SH-SY5Y
cells. IKKβ deficiency increased expression of PP2A catalytic subunit isoform A,
an enzyme dephosphorylating cerebral p-tau, in the brain of tau-transgenic mice.
Interestingly, deficiency of IKKβ in neurons enhanced autophagy as indicated by
the increased ratio of LC3B-II/I in brains of both APP- and tau-transgenic mice.
Thus, IKKβ deficiency in neurons ameliorates AD-associated pathology in APPand tau-transgenic mice, perhaps by decreasing Aβ production, increasing p-tau
dephosphorylation, and promoting autophagy-mediated degradation of BACE1
and p-tau aggregates in the brain. However, IKKβ deficiency differently protects
neurons in APP- and tau-transgenic mice. Further studies are needed, particularly in the context of interaction between Aβ and p-tau, before IKKβ/NF-κB can
be targeted for AD therapies
Haploinsufficiency of microglial MyD88 ameliorates Alzheimer's pathology and vascular disorders in APP/PS1-transgenic mice
Growing evidence indicates that innate immune molecules regulate microglial activation in Alzheimer's disease (AD); however, their effects on amyloid pathology and neurodegeneration remain inconclusive. Here, we conditionally deleted one allele of myd88 gene specifically in microglia in APP/PS1-transgenic mice by 6 months and analyzed AD-associated pathologies by 9 months. We observed that heterozygous deletion of myd88 gene in microglia decreased cerebral amyloid β (Aβ) load and improved cognitive function of AD mice, which was correlated with reduced number of microglia in the brain and inhibited transcription of inflammatory genes, for example, tnf-α and il-1β, in both brain tissues and individual microglia. To investigate mechanisms underlying the pathological improvement, we observed that haploinsufficiency of MyD88 increased microglial recruitment toward Aβ deposits, which might facilitate Aβ clearance. Microglia with haploinsufficient expression of MyD88 also increased vasculature in the brain of APP/PS1-transgenic mice, which was associated with up-regulated transcription of osteopontin and insulin-like growth factor genes in microglia. Moreover, MyD88-haploinsufficient microglia elevated protein levels of LRP1 in cerebral capillaries of APP/PS1-transgenic mice. Cell culture experiments further showed that treatments with interleukin-1β decreased LRP1 expression in pericytes. In summary, haploinsufficiency of MyD88 in microglia at a late disease stage attenuates pro-inflammatory activation and amyloid pathology, prevents the impairment of microvasculature and perhaps also protects LRP1-mediated Aβ clearance in the brain of APP/PS1-transgenic mice, all of which improves neuronal function of AD mice
Correlation between Myocardial Velocity Measured using Tissue Doppler Imaging in the Left Ventricular Lead-Implanted Segment and Response to Cardiac Resynchronization Therapy
OBJECTIVES: This study investigated whether tissue Doppler imaging parameters, especially the peak systolic velocity of the left ventricular lead-implanted segment (Ss), affect cardiac resynchronization therapy response. METHODS: In this case-control study, 110 enrolled patients were divided into cases (responder group, n=65) and controls (nonresponder group, n=45) based on whether their left ventricular end-systolic volume was reduced by X15% at 6 months after surgery. Preoperative clinical and echocardiographic data were collected. Multivariate logistic regression models were used to analyze the factors affecting the response to cardiac resynchronization therapy, and receiver operating characteristic curves were plotted to evaluate their diagnostic values. RESULTS: The proportion of patients with left bundle branch block in the case group was higher than that in the control group. The control group showed a higher left atrial volume index, E/A ratio and E/Em ratio but lower Ss than that of the case group. A multivariate regression analysis showed that left bundle branch block, Ss, and an E/Em ratio414 were independent risk factors affecting the response to cardiac resynchronization therapy. Ss=4.1 cm/s was the best diagnostic threshold according to the receiver operating characteristic curve. CONCLUSIONS: Ss is an important factor affecting the response to cardiac resynchronization therapy. Patients with heart failure associated with Sso4.1 cm/s have a higher risk of nonresponse
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