Enhanced stability and clinical absorption of a form of encapsulated vitamin A for food fortification

Food fortification is an effective strategy to address vitamin A (VitA) deficiency, which is the leading cause of childhood blindness and drastically increases mortality from severe infections. However, VitA food fortification remains challenging due to significant degradation during storage and cooking. We utilized an FDA-approved, thermostable, and pH-responsive basic methacrylate copolymer (BMC) to encapsulate and stabilize VitA in microparticles (MPs). Encapsulation of VitA in VitA-BMC MPs greatly improved stability during simulated cooking conditions and long-term storage. VitA absorption was nine times greater from cooked MPs than from cooked free VitA in rats. In a randomized controlled cross-over study in healthy premenopausal women, VitA was readily released from MPs after consumption and had a similar absorption profile to free VitA. This VitA encapsulation technology will enable global food fortification strategies toward eliminating VitA deficiency.

Vitamin A (VitA) plays an essential role in visual health, immune function, and fetal growth and development (1). VitA deficiency (VAD) arises from diets with insufficient fat-soluble micronutrients (MNs) and is currently estimated as the second most common cause of malnutrition, after iron, globally (2). VAD can lead to xerophthalmia (preventable childhood blindness) and weakened host resistance to infection, which can increase the risk of mortality from infectious diseases, such as measles and COVID-19 (3, 4). The WHO estimated that VAD affected 190 million preschool-age children (33.3% of the preschool-age population) and >19 million pregnant women (15.3% of the pregnant population) globally in the period spanning 1995–2005 (5). The most severely affected regions still reached VAD prevalence levels of 48% in sub-Saharan Africa and 44% in South Asia in children in 2013 (6). To reduce the high burden of VAD, a VitA supplementation program was implemented worldwide in 1990 that distributed high-dose VitA capsules every 4–6 mo to over 80% of the total child population in low-income countries (7). This project effectively reduced all-cause mortality caused by severe VAD by 12% (8). However, progress toward VAD elimination was limited to a rate of improvement of only ~0.3% per year from 1990 to 2007, showing that more impactful strategies are required (9, 10).To raise and maintain serum retinol levels, frequent intake of VitA at physiological doses is proven to be more effective than one or two high doses administered over 6 mo (11). However, VitA food fortification is challenging due to its poor stability, which can lead to poor bioavailability after degradation, and fat solubility, which limits the inclusion of VitA in water-based and dry food matrices (12). To prevent VitA degradation and improve miscibility, VitA has previously been encapsulated within matrices composed of polysaccharides (13), proteins (14), and/or lipids (15); however, these materials provide limited protection during storage and cooking (16 –18) and can take up to 3 h to release in the stomach (19). Poor protection and slow release of VitA prevent effective absorption. Therefore, the ideal microparticle (MP) platform for VitA fortification should meet these criteria: i) protect VitA against degradation during storage and cooking; ii) rapidly release VitA in the gastrointestinal tract with high absorption; and iii) readily mix with various food matrices at a tunable concentration to meet the dynamic needs of the target population.We hypothesized that by encapsulating VitA with a pH-responsive hydrophobic polymer, we could enhance stability during storage and cooking and ensure its rapid release in the gastrointestinal tract for subsequent absorption. A commercially available, FDA-approved basic methacrylate copolymer (BMC), also known as either Eudragit® E PO or GRAS-status Eudraguard®, was identified from our previous work (20). BMC is generally regarded as safe with an acceptable daily intake of 20 mg/kg body weight (21). VitA-encapsulated BMC MPs were prepared by emulsion at the laboratory scale and by a commercial process at the kilogram scale. Our VitA-BMC-S MPs readily mix with flour and bouillon cubes and demonstrate enhanced stability under cooking and long-term storage conditions (over 12 mo) in comparison to a leading commercial encapsulated VitA product. The bioavailability of VitA from VitA-BMC MPs was first demonstrated in a rodent model, resulting in a ninefold increase in the accumulation of VitA in the liver from cooked VitA-BMC MPs, as compared to cooked unencapsulated free VitA. In a human clinical study, the absorption of VitA from bread fortified with VitA-BMC-S MPs was investigated, with or without the codelivery of encapsulated iron sulfate (FeSO₄) and folic acid (FA), MNs that children and pregnant women globally are also often deficient in (22, 23). The results indicate that VitA is readily released and absorbed from VitA-BMC-S MPs, and the codelivery of encapsulated iron and free FA does not influence the absorption of VitA. In total, we demonstrated scalable production of MP-encapsulated VitA with enhanced stability and good bioavailability in humans, which could potentially mitigate the high burden of VAD and be codelivered with other MNs.     

Effect of Volume Fraction of Reinforcement on Microstructure and Mechanical Properties of In Situ (Ti,Nb)B/Ti2AlNb Composites with Tailored Three-Dimensional Network Architecture

The mechanical properties of (Ti, Nb)B/Ti₂AlNb composites were expected to improve further by utilizing spark plasma sintering (SPS) and inducing the novel three-dimensional network architecture. In this study, (Ti, Nb)B/Ti₂AlNb composites with the novel architecture were successfully fabricated by ball milling the LaB₆ and Ti₂AlNb mixed powders and subsequent SPS consolidation. The influence of the (Ti, Nb)B content on the microstructure and mechanical properties of the composites was revealed by using the scanning electron microscope (SEM), transmission electron microscopy (TEM) and electronic universal testing machine. The microstructural characterization demonstrated that the boride crystallized into a B27 structure and the α₂-precipitated amount increased with the (Ti, Nb)B increasing. When the (Ti, Nb)B content reached 4.9 vol%, both the α₂ and reinforcement exhibited a continuous distribution along the prior particle boundaries (PPBs). The tensile test displayed that the tensile strength of the composites presented an increasing trend with the increasing (Ti, Nb)B content followed by a decreasing trend. The composite with a 3.2 vol% reinforcement had the optimal mechanical properties; the yield strengths of the composite at 25 and 650 °C were 998.3 and 774.9 MPa, showing an 11.8% and 9.2% improvement when compared with the Ti₂AlNb-based alloy. Overall, (Ti, Nb)B possessed an excellent strengthening effect and inhibited the strength weakening of the PPBs area at high temperatures; the reinforcement content mainly affected the mechanical properties of the (Ti, Nb)B/Ti₂AlNb composites by altering the α₂-precipitated amount and the morphology of (Ti, Nb)B in the PPBs area. Both the continuous precipitation of the brittle α₂ phase and the agglomeration of the (Ti, Nb)B reinforcement dramatically deteriorated the mechanical properties.     

核工业某厂放射工作人员与非放射工作人员的MDM2基因表达调查与分析

目的 探讨核工业某厂放射工作人员与非放射工作人员辐射敏感基因表达的差异。 方法 采集了3名健康人外周血进行60Co γ射线照射,建立辐照后鼠双微体基因2（MDM2）表达的剂量-效应关系,抽取核工业某厂96名工作人员（49名放射工作人员、47名非放射工作人员）外周血,利用实时荧光定量PCR技术检测放射工作人员外周血中MDM2基因的表达情况。 结果 在0~2 Gy剂量范围内,MDM2的表达水平随照射剂量增加而上升。某厂96名工作人员外周血MDM2基因表达水平的检测分析结果表明,非放射工作人员年龄因素对外周血MDM2基因表达无影响（F=2.11,P＞0.05）;放射工作人员外周血MDM2基因表达与非放射工作人员相比,差异具有统计学意义（t=7.78,P＜0.05）。 结论 电离辐射可以诱导人离体外周血MDM2基因表达改变,且基因表达与照射剂量存在一定的剂量相关性,MDM2有望成为核工业放射工作人员健康调查的敏感指标。     

Cerebral cortex layer segmentation using diffusion magnetic resonance imaging in vivo with applications to laminar connections and working memory analysis

Understanding the laminar brain structure is of great help in further developing our knowledge of the functions of the brain. However, since most layer segmentation methods are invasive, it is difficult to apply them to the human brain in vivo. To systematically explore the human brain''s laminar structure noninvasively, the K‐means clustering algorithm was used to automatically segment the left hemisphere into two layers, the superficial and deep layers, using a 7 Tesla (T) diffusion magnetic resonance imaging (dMRI)open dataset. The obtained layer thickness was then compared with the layer thickness of the BigBrain reference dataset, which segmented the neocortex into six layers based on the von Economo atlas. The results show a significant correlation not only between our automatically segmented superficial layer thickness and the thickness of layers 1–3 from the reference histological data, but also between our automatically segmented deep layer thickness and the thickness of layers 4–6 from the reference histological data. Second, we constructed the laminar connections between two pairs of unidirectional connected regions, which is consistent with prior research. Finally, we conducted the laminar analysis of the working memory, which was challenging to do in the past, and explained the conclusions of the functional analysis. Our work successfully demonstrates that it is possible to segment the human cortex noninvasively into layers using dMRI data and further explores the mechanisms of the human brain.     

Effectiveness of moist dressings in wound healing after surgical suturing: A Bayesian network meta‐analysis of randomised controlled trials

The moist healing theory proves that a moderately moist and airtight environment is conducive to wound healing. However, different moist dressings have different functions. We aim to evaluate the effects of moist dressings on wound healing after surgical suturing and identify superior moist dressings. Randomised controlled trials investigating the application of moist dressings were retrieved from electronic databases, including PubMed, EMBASE, Web of Science, and the Cochrane Library. Wound healing, surgical site infection (SSI), and times of dressing change were assessed. The values of the surface under the cumulative ranking (SUCRA) curve were calculated based on the Bayesian network meta‐analysis. Inconsistency tests and funnel plots were applied to analyse the consistency and publication bias. All the analysis complies with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta‐Analyses) 2020 Checklist and AMSTAR (Assessing the Methodological Quality of Systematic Reviews) Guidelines. Sixteen randomised controlled trials involving 4444 patients were pooled in the network meta‐analysis. The ionic silver dressing (SUCRA, 93%) ranked first in wound healing, the metallic silver dressing (SUCRA, 75.9%) ranked first in SSI, and the hydrocolloid dressing (SUCRA, 73.9%) ranked first in times of dressing change. Inconsistency was only observed in wound healing, and no publication bias was observed in this study. The effects of moist dressings are better than gauze dressings in the process of wound healing. The ionic silver dressing is effective in wound healing, whereas the metallic silver dressing is effective in SSI prevention. The hydrocolloid dressing requires the fewest times of dressing change. More high‐quality RCTs are required to support the network meta‐analysis.     

中小医院PACS云服务平台架构研究

目的设计一种基于云计算技术的新型PACS模式,从而减少中小医院PACS系统建设的难度和成本。方法结合云计算技术中的SaaS模式,提出了基于云计算技术的SaaS模式的“云PACS”。并从云显示、云工作流以及云归档等3个部分设计了“云PACS”。结果“云PACS”这种灵活租用的软件使用模式,可以缩短中小医院PACS建设的周期,减少建设以及维护所需的成本。结论基于云计算的PACS将是新一代PACS的发展方向,将为中小医院、区域医疗以及集团化医院的PACS建设带来新的思路。