Physiological effects of a short-term, lifestyle intervention based on the Mediterranean diet - comparison between older and younger healthy, sedentary adults

Objective: To determine whether short-term adherence to the Mediterranean Diet (MD) is associated with improved physiological function. Research Methods and Procedures: This was a single-centre, cohort pilot study. Twenty-four healthy, sedentary younger (18-35 years) and older (55-75 years) adults took part. Participants were advised and supported to follow the Mediterranean diet for 4 weeks. We took baseline and post-intervention measurements of weight, height, waist and hip circumference, blood pressure, heart rate, as well as microvascular physiological assessments using laser Doppler Fluximetry (LDF) at rest as well as transcutaneous oxygen pressure (TcPO2) during a sub-maximal exercise assessment. Results: We identified statistically-significant improvements in axon-mediated microvascular vasodilation (2.24 (±0.56) to 3.14 (±0.84), P =0.03) and endothelial-mediated NO synthesis (2.59 (±0.67) to 3.32 (±0.87), P =0.022) in the younger group. Despite the intervention not including an exercise element, the rate of perceived exertion was reduced in both groups (p<0.001), after following the MD for a month. Conclusions: Improvements in physiological function were observed following a short-term dietary intervention based on the MD in a younger population. These were not matched in a senior group. Our findings suggest that different durations should be applied when designing dietary interventions in different age-groups, with expectations in physiological improvements differing. Keywords: Mediterranean diet, LDF, Oxygen tension, cardiovascular disease, blood pressure

Contrasting effects of short-term mediterranean and vegan diets on microvascular function and cholesterol in younger adults: A comparative pilot study

The Mediterranean diet has been shown to improve cardiovascular health. Vegan diets have demonstrated similar benefits, albeit in fewer studies. In a comparative pilot study, we compared the effects of a short-term Mediterranean Diet (MD) and Vegan Diet (VD) on microvascular function and cholesterol levels in a healthy population. Twenty-four young (aged 18 to 35 years) healthy volunteers followed a four-week intervention (MD = 12; VD = 12) ad libitum. Pre and post-intervention anthropometrics, microvascular function (assessed via LDF and expressed as raw CVC and %CVC MAX), dietary-analysis data (Calories, Protein, Carbohydrates, Total Fat, Saturated Fat, Fibre), Mean Arterial Pressure (MAP), Blood Pressure, Total Cholesterol (TC), High Density Lipoprotein (HDL-C) and TC:HDL-C were compared. MD participants reduced Total Fat intake (p = 0.05). Saturated Fat decreased (MD: p = &lt; 0.001; VD: p = 0.004) and Fibre increased (MD: p = 0.02; VD: p = &lt; 0.001) in both groups. Dietary changes reflected improvements in plateau raw CVC in the MD group (p = 0.005), and a reduction in TC (p = 0.045) and weight loss (p = 0.047) in the VD group. The MD led to improvements in microvascular function; the VD led to reduced TC and weight loss. Although both diets might offer CVD risk-reduction benefits, evidence for the MD appeared to be stronger due to changes in vasodilatory ability and NO bioavailability

Effects of Long-Versus Short-Term Exposure to the Mediterranean Diet on Skin Microvascular Function and Quality of Life of Healthy Adults in Greece and the UK

The beneficial effects of the Mediterranean diet (MD) adherence in reducing cardiovascular disease (CVD) risk and improving CVD-related physiological indices have been well-documented. However, the exact MD adherence duration needed for these effects to occur is under-researched. The aim of the present, two-arm, two-site study clinical trial was to assess the effects of long- vs. short-term MD adherence on the skin microvascular circulation, and quality of life. Two groups were recruited, one being long-term MD adherers (>5 years; from Greece; control group), and one of the non-adherers (from the UK), with the latter participating in a four-week MD intervention (intervention group). Our main outcome was skin microvascular function assessed by cutaneous vascular conductance (CVC). Secondary outcomes included quality of life, dietary intake, blood pressure and lipidemic profile. At the end of the intervention, both groups had high MD adherence. For the intervention group, significantly improved post-intervention CVC values were noted concerning the initial peak phase (2.0 ± 0.6 vs. 2.8 ± 0.8; p 0.05). CVC values of the control group, were however higher at the plateau phase in comparison to the intervention group (intervention end; 3.8 ± 0.8 vs. 3.1 ± 1.2; p 0.05). As per QoL, the physical domain was improved post-intervention (13.7 ± 1.2 vs. 15.9 ± 1.2; p 0.05). No differences were observed in the lipidemic profile between groups, or between the baseline and final intervention phases. The findings indicate that although short-term MD adherence is effective in improving certain microvascular physiological properties and QoL domains, there is room for additional improvement, observed in long-term adherers. Our findings are important in the design of future, MD-based, lifestyle interventions, with the advisable durations differing between target groups

Photopolymerized maleilated chitosan/methacrylated silk fibroin micro/nanocomposite hydrogels as potential scaffolds for cartilage tissue engineering

Hydrogels composed of natural materials exhibit great application potential in artificial scaffolds for cartilage repair as they can resemble the extracellular matrices of cartilage tissues comprised of various glycosaminoglycan and collagen. Herein, the natural polymers with vinyl groups, i.e. maleilated chitosan (MCS) and methacrylated silk fibroin (MSF) micro/nanoparticles, were firstly synthesized. The chemical structures of MCS and MSF micro/nanoparticles were investigated using Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (1H NMR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Then MCS/MSF micro/nanocomposite hydrogels were prepared by the photocrosslinking of MCS and MSF micro/nanoparticles in aqueous solutions in the presence of the photoinitiator Darocur 2959 under UV light irradiation. A series of properties of the MCS/MSF micro/nanocomposite hydrogels including rheological property, equilibrium swelling, sol content, compressive modulus, and morphology were examined. The results showed that these behaviors could be tunable via the control of MSF content. When the MSF content was 0.1%, the hydrogel had the compressive modulus of 0.32±0.07MPa, which was in the range of that of articular cartilage. The in vitro cytotoxic evaluation and cell culture of the micro/nanocomposite hydrogels in combination with mouse articular chondrocytes were also investigated. The results demonstrated that the micro/nanocomposite hydrogels with TGF-β1 was biocompatible to mouse articular chondrocytes and could support cells attachment well, indicating their potential as tissue engineering scaffolds for cartilage repair.This study was supported by National Natural Science Foundation of China (Grant No. 51203123, 51403165, 51503161) and the National Key Research and Development Program of China (No.2016YFA0101102)

Development of China’s first space-borne aerosol-cloud high-spectral-resolution lidar: retrieval algorithm and airborne demonstration

Aerosols and clouds greatly affect the Earth’s radiation budget and global climate. Light detection and ranging (lidar) has been recognized as a promising active remote sensing technique for the vertical observations of aerosols and clouds. China launched its first space-borne aerosol-cloud high-spectral-resolution lidar (ACHSRL) on April 16, 2022, which is capable for high accuracy profiling of aerosols and clouds around the globe. This study presents a retrieval algorithm for aerosol and cloud optical properties from ACHSRL which were compared with the end-to-end Monte-Carlo simulations and validated with the data from an airborne flight with the ACHSRL prototype (A2P) instrument. Using imaging denoising, threshold discrimination, and iterative reconstruction methods, this algorithm was developed for calibration, feature detection, and extinction coefficient (EC) retrievals. The simulation results show that 95.4% of the backscatter coefficient (BSC) have an error less than 12% while 95.4% of EC have an error less than 24%. Cirrus and marine and urban aerosols were identified based on the airborne measurements over different surface types. Then, comparisons were made with U.S. Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) profiles, Moderate-resolution Imaging Spectroradiometer (MODIS), and the ground-based sun photometers. High correlations (R > 0.79) were found between BSC (EC) profiles of A2P and CALIOP over forest and town cover, while the correlation coefficients are 0.57 for BSC and 0.58 for EC over ocean cover; the aerosol optical depth retrievals have correlation coefficient of 0.71 with MODIS data and show spatial variations consistent with those from the sun photometers. The algorithm developed for ACHSRL in this study can be directly employed for future space-borne high-spectral-resolution lidar (HSRL) and its data products will also supplement CALIOP data coverage for global observations of aerosol and cloud properties

Further results on the orthogonal arrays obtained by generalized Hadamard product

By combining generalized Hadamard product with difference matrix and exploring the relationship between orthogonal arrays and decomposition of projection matrix, we furthermore develop the method in Zhang et al. (Discrete Math. 238 (2001) 151). As an application of it, some new orthogonal arrays of run size 100 are constructed.Mixed-level orthogonal array Generalized Hadamard product Difference matrix Projection matrix

Satisfactory orthogonal array and its checking method

An orthogonal array (OA) is said to be a satisfactory orthogonal array if it is impossible to obtain another OA from it by adding one or more columns. By exploring the relationship between OAs and orthogonal decompositions of projection matrices, we present a method of checking a satisfactory OA.Projection matrix Satisfactory orthogonal array

A note on orthogonal arrays obtained by orthogonal decomposition of projection matrices

A method of constructing mixed-level orthogonal arrays is presented by Zhang et al. (Statist. Sinica 2, 595). It is somewhat difficult to use this method to obtain new orthogonal arrays. This paper illustrates with examples the application of the method. Several classes of mixed-level orthogonal arrays are obtained.Mixed-level orthogonal array Projection matrix Permutation matrix

Normal mixed difference matrix and the construction of orthogonal arrays

We present the definitions of normal orthogonal array (OA) and normal mixed difference matrix and extend the mixed difference matrix method introduced by Wang (Statist. Probab. Lett. 28, 121). Some new mixed-level OAs are constructed through the generalized Kronecker sum of (nonorthogonal) mixed-level matrix and normal mixed difference matrices.Mixed orthogonal array Mixed difference matrix Normal mixed difference matrix Generalized Kronecker sum