Dynamics of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) involving fractional derivative with Mittag-Leffler kernel

Since 2012, the Middle East has seen a steady rise in the Middle East Respiratory Syndrome Coronavirus (MERS-CoV). A fractional derivative of the non-singular Mittag-Leffler type is used in this research to conduct a mathematical analysis of the dynamics of MERS-CoV infection transmission. The dynamics of such a disease with an additional degree of freedom and non-singular behavior are discovered through the use of the aforementioned fractional operator, and this is one of the important components of our prepared paper. Using the concept of fixed point theory, the existence and uniqueness of solutions are demonstrated. The stability analysis is also tested with the help of the Ulam-Hyers approach, respectively. The numerical solution has been conducted by using the fractional Adams-Bashforth scheme. In the numerical simulation, all classes are demonstrated through the graphical presentation regarding the changing values of fractional-order at time t. The results at various fractional-order laying between (0,1] are drawn with the help of Matlab. We also provide a comparison of the proposed approach with that of the Caputo operator. The outcomes that were achieved illustrate that the considered scheme is highly methodical and very efficient compared to the Caputo fractional operator.

Prevalence and Correlates of Weight Stigma among Postpartum Women in China

Weight stigma is linked to a variety of psychological and health problems. In the postpartum period, women may be more likely to experience weight-based discrimination because of their changing social roles, weight, and the new functions their bodies fulfill. However, few studies have explored the issue of postpartum women's weight stigma. Thus, to investigate the prevalence and correlates of weight stigma for postpartum women in China, we conducted a cross-sectional study of 507 postpartum women. Results showed that almost one quarter (21.1%) of postpartum women claimed to have experienced perceived weight stigma (PWS). Two thirds (66.1%) scored at the mean and 14.8% at the highest levels of weight bias internalization (WBI). During the postnatal period, the conditions of those most likely to report experiences of weight-based discrimination included low income [b = -0.203, p = 0.004], occupation as a worker [b = 0.921, p = 0.017] or farmer [b = 0.826, p = 0.033], stress [b = 0.044, p = 0.035], depression [b = 0.057, p = 0.021], and higher WBIS [b = 0.018, p = 0.002]. In addition, postpartum women who lived alone [b = 7.511, p = 0.048], were overweight or obese [b = 5.443, p = 0.000], and had higher PWS [b = 0.897, p = 0.004] and anxiety symptoms [b = 0.219, p = 0.011] had higher levels of internalized weight stigma. Findings from this study provide a foundation to better understand characteristics of postpartum women in China who are at risk for weight stigma.

Internalised stigma, social support, coping and care-giving burden among Chinese family caregivers of adults diagnosed with schizophrenia: A parallel mediation analysis

Care-giving burden and internalised stigma are prevalent among family caregivers of people diagnosed with schizophrenia. Internalised stigma has been regarded as a source of care-giving burden. But it remains unclear if high levels of internalised stigma directly contribute to an increased risk of care-giving burden or if the effects could be buffered by psychological factors. This cross-sectional study was to investigate the relationship between internalised stigma and care-giving burden, and to determine the mediating effects of coping styles and social support. Data were collected from 344 Chinese family caregivers of adults diagnosed with schizophrenia in a psychiatric outpatient department of a tertiary hospital in Changsha, Hunan between April and August 2018. A self-reported questionnaire was used to collect data anonymously. Instruments included the Simplified Coping Style Questionnaire, the Multidimensional Scale of Perceived Social Support, the Internalized Stigma of Mental Illness Scale and the Caregiver Burden Inventory. Data analysis was conducted using descriptive statistics, the Spearman correlation and regression analysis to estimate direct and indirect effects using bootstrap analysis. Results showed that internalised stigma, social support and passive coping were significant correlates of care-giving burden; social support partially mediated the relationship between internalised stigma and care-giving burden; active coping did not show impacts on internalised stigma and care-giving burden. This study provided social workers and healthcare providers with a better understanding of the development of care-giving burden. Comprehensive interventions should be designed to provide supportive resources and reduce the possibilities of internalisation of stigma and passive coping, to alleviate care-giving burden.

Biglycan has a major role in maintenance of mature tendon mechanics

Decorin and biglycan are two small leucine-rich proteoglycans (SLRPs) that regulate collagen fibrillogenesis and extracellular matrix assembly in tendon. The objective of this study was to determine the individual roles of these molecules in maintaining the structural and mechanical properties of tendon during homeostasis in mature mice. We hypothesized that knockdown of decorin in mature tendons would result in detrimental changes to tendon structure and mechanics while knockdown of biglycan would have a minor effect on these parameters. To achieve this objective, we created tamoxifen-inducible mouse knockdown models targeting decorin or biglycan inactivation. This enables the evaluation of the roles of these SLRPs in mature tendon without the abnormal tendon development caused by conventional knockout models. Contrary to our hypothesis, knockdown of decorin resulted in minor alterations to tendon structure and no changes to mechanics while knockdown of biglycan resulted in broad changes to tendon structure and mechanics. Specifically, knockdown of biglycan resulted in reduced insertion modulus, maximum stress, dynamic modulus, stress relaxation, and increased collagen fiber realignment during loading. Knockdown of decorin and biglycan produced similar changes to tendon microstructure by increasing the collagen fibril diameter relative to wild-type controls. Biglycan knockdown also decreased the cell nuclear aspect ratio, indicating a more spindle-like nuclear shape. Overall, the extensive changes to tendon structure and mechanics after knockdown of biglycan, but not decorin, provides evidence that biglycan plays a major role in the maintenance of tendon structure and mechanics in mature mice during homeostasis.

Effects of glucose availability on αS1-casein synthesis in bovine mammary epithelial cells

Glucose has been demonstrated to affect milk protein synthesis in dairy cows. However, its potential mechanisms has not been thoroughly studied. The objective of this study was to investigate the effects of glucose availability on αS1-casein synthesis, glucose uptake, metabolism, and the expression of proteins involved in AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signaling pathway in bovine mammary epithelial cells (BMEC). BMEC were treated for 24 h with different concentrations of glucose (0, 7, 10.5, 14, 17.5, and 21 mM). The results showed that 10.5 and 14 mM glucose supply increased the expression of αS1-casein, glucose uptake, cellular ATP content, and the phosphorylation of mTOR and P70S6K, but repressed AMPK phosphorylation in BMEC. Compared with 10.5 and 14 mM glucose supply, 17.5 and 21 mM glucose decreased the expression of αS1-casein, P70S6K phosphorylation as well as the activity of hexokinase (HK) and pyruvate kinase (PK), but increased the activity of glucose-6-phosphate dehydrogenase (G6PD). These results indicate that 10.5 to 14 mM glucose supply is the proper range for αS1-casein synthesis, and the promotion effects may be related to the increase of glucose uptake, ATP content and the changes of key proteins' phosphorylation in AMPK/mTOR signaling pathway. However, the inhibition of the expression of αS1-casein by 17.5 and 21 mM glucose may be associated with the changes of key enzymes' activity involved in glucose metabolism.

Deciphering the role of microplastic size on anaerobic sludge digestion: Changes of dissolved organic matter, leaching compounds and microbial community

Here the role of microplastic size on dissolved organic matter, leaching compounds and microbial community during anaerobic sludge digestion was evaluated. Compared to that without the addition of polyvinyl chloride (PVC), during the 30 days' incubation, the anaerobic sludge digestion by adding PVC at the size of 75 μm and the concentration of 2.4 g/g volatile solids (VS) showed a 8.5% lower cumulative methane production, while a 17.9% higher cumulative methane production was noted by adding PVC at the size of 3000 μm and the concentration of 2.4 g/g VS. A long-term fed-batch laboratory-scale fermenter test for 147 days further testified, that higher removal efficiencies of total solids, volatile solids, and total chemical oxygen demand, and higher methane production were noted by adding PVC (2.4 g/g VS, 3000 μm) into the fermenter. More interestingly, higher concentrations of proteins, polysaccharides, volatile fatty acids, and soluble microbial by-products component were noted in the liquid phase of sludge drawn from the fermenter added with PVC since the biomass therein showed higher efficiencies of solubilization, hydrolysis, acidification, and methanogenesis. Moreover, as identified from the fermenter added with PVC, dibutyl phthalate (DBP) was the most predominant leaching phthalates compound, although the biomass therein showed a 93.4% anaerobic biodegradability of DBP. The leaching of DBP drove the predominance of microbial community towards Synergistota and Methanosaeta. More irregular elliptical shallow dimples were noted on the PVC surface after 147 days' incubation, accompanied with abundances of Proteobacteria, Actinobacteriota, Chloroflexi, Methanosaeta and Methanobacterium. The results from this study showed that the size of microplastic was a crucial factor in evaluating its impact on anaerobic sludge digestion.

Targeted conditional collagen XII deletion alters tendon function

Collagen XII is a fibril-associated collagen with interrupted triple helices (FACIT). This non-fibrillar collagen is a homotrimer composed of three α1(XII) chains assembled into a collagenous molecule with a C terminal collagenous domain and a large N terminal non-collagenous domain. During tendon development and growth, collagen XII is broadly expressed throughout the extracellular matrix and enriched pericellularly around tenocytes. Tendons in a global Col12a1 ^-/- knockout model demonstrated disrupted fibril and fiber structure and disordered tenocyte organization, highlighting the critical regulatory roles of collagen XII in determining tendon structure and function. However, muscle and bone also are affected in the collagen XII knockout model. Therefore, secondary effects on tendon due to involvement of bone and muscle may occur in the global knockout. The global knockout does not allow the definition of intrinsic mechanisms involving collagen XII in tendon versus extrinsic roles involving muscle and bone. To address this limitation, we created and characterized a conditional Col12a1-null mouse model to permit the spatial and temporal manipulation of Col12a1 expression. Collagen XII knockout was targeted to tendons by breeding conditional Col12a1 ^flox/flox mice with Scleraxis-Cre (Scx-Cre) mice to yield a tendon-specific Col12a1-null mouse line, Col12a1 ^Δten/Δten . Both mRNA and protein expression in Col12a1 ^Δten/Δten mice decreased to near baseline levels in flexor digitorum longus tendons (FDL). Collagen XII immuno-localization revealed an absence of reactivity in the tendon proper, but there was reactivity in the cells of the surrounding peritenon. This supports a targeted knockout in tenocytes while peritenon cells from a non-tendon lineage were not targeted and retained collagen XII expression. The tendon-targeted, Col12a1 ^Δten/Δten  mice had significantly reduced forelimb grip strength, altered gait and a significant decrease in biomechanical properties. While the observed decrease in tendon modulus suggests that differences in tendon material properties in the absence of Col12a1 expression underlie the functional deficiencies. Together, these findings suggest an intrinsic role for collagen XII critical for development of a functional tendon.

Mixed nuts with high nutrient density improve insulin resistance in mice by gut microbiota remodeling

The consumption of mixed nuts is a healthy dietary strategy to reduce the risk of cardiovascular disease and has a prebiotic effect on the gut microbiota. However, there is a lack of basic research based on mixed nut formulation. This study established a new method for optimizing mixed nut formulations using the Nutrient Rich Food (NRF) index model. Nutrient indices were adjusted by combining 10 and 8 encouraging nutrients and 3 limiting nutrients of nuts and dried fruits, respectively. The optimized mixed nut formulation had the highest total NRF and the lowest energy, which was achieved by applying linear programming. The effect of an optimized mixed nut formulation on insulin resistance and gut microbiota was investigated in an animal model of metabolic disorders caused by a high-fat diet. Male C57BL/6J mice (n = 12 per group) were fed a low-fat diet, a high-fat diet (HFD), HFD with a supplemented classical randomized controlled trial mixed nut formula (MN1), a commercially available mixed nut formula (MN2), a high-nutrient density mixed nut formula (MN3), or ellagic acid (positive control). MN3 treatment decreased total plasma cholesterol, homeostasis model assessment-insulin resistance index, high sensitivity C-reactive protein, and zonulin levels, strengthened the intestinal barrier, and significantly altered the β-diversity of the intestinal microbiota as compared to the HFD group. These effects of MN3 were superior to MN1 and MN2. In conclusion, MN3 had the highest nutrient density and improved insulin resistance in low-grade inflammation via gut microbiota remodeling.

Perioperative stress prolong post-surgical pain via miR-339-5p targeting oprm1 in the amygdala

Background

The decreased expression of mu-opioid receptors (MOR) in the amygdala may be a key molecular in chronic post-surgical pain (CPSP). It is known that miR-339-5p expression in the amygdala of a stressed rat model was increased. Analyzed by RNAhybrid, miR-339-5p could target opioid receptor mu 1 (oprm1) which codes MOR directly. So, the authors hypothesized that miR-339-5p could regulate the expression of MOR via targeting oprm1 and cause the effects to CPSP.

Methods

To simulate perioperative short-term stress, a perioperative stress prolongs incision-induced pain hypersensitivity without changing basal pain perception rat model was built. A pmiR-RB-REPORT™ dual luciferase assay was taken to verify whether miR-339-5p could act on oprm1 as a target. The serum glucocorticoid level of rats was test. Differential expressions of MOR, GFAP, and pERK1/2 in each group of the rats' amygdala were tested, and the expressions of miR-339-5p in each group of rats' amygdalas were also measured.

Results

Perioperative stress prolonged the recovery time of incision pain. The expression of MOR was down-regulated in the amygdala of rats in stress + incision (S + IN) group significantly compared with other groups (P < 0.050). miR-339-5p was up-regulated in the amygdala of rats in group S + IN significantly compared with other groups (P < 0.050). miR-339-5p acts on oprm1 3'UTR and take MOR mRNA as a target.

Conclusions

Perioperative stress could increase the expression of miR-339-5p, and miR-339-5p could cause the expression of MOR to decrease via targeting oprm1. This regulatory pathway maybe an important molecular mechanism of CPSP.

Effects of long-term organic matter application on soil carbon accumulation and nitrogen use efficiency in a double-cropping rice field

Increasing soil carbon (C) sequestration in paddy field and improving rice nitrogen use efficiency (NUE) are vital for sustainable agriculture and environmental protection. It was a benefit practice for achieving these goals by taken rice straw and organic manure managements. However, there is still need to further investigate the effects of different long-term fertilizer managements on soil C sequestration and NUE under the double-cropping rice system in southern of China. Therefore, the effects of different long-term (36-years) fertilizer practices on soil C sequestration and NUE under the double-cropping rice system in southern of China were investigated in the present paper. The field experiment was included four different fertilizer treatments: chemical fertilizer alone (MF), rice straw residue and chemical fertilizer (RF), 30% organic manure and 70% chemical fertilizer (OM), and without fertilizer input as a control (CK). This result indicated that soil C content at plough layer in paddy field with RF and OM treatments were increased, compared with MF and CK treatments. Besides input C directly into paddy field, soil original organic C accumulation with RF and OM treatments were increased by 1.54% and 3.01%, compared with MF treatment. This result indicated that soil TOC content increase rate and annual topsoil organic C sequestration rate in paddy field with RF and OM treatments increased by 55.56%, 88.89% and 48.05%, 76.62%, compared with MF treatment, respectively. Compared with MF treatment, NUE with RF and OM treatments increased by 10.43% and 22.61%, respectively, mainly due to increasing soil organic C. Grain yield of double-cropping rice with RF and OM treatments increased by 1009.5 and 1166.5 kg ha^-1, compared with MF treatment, respectively. This result indicated that there was significantly correlation between NUE/NUE_NPK and TOC content with RF and OM treatments, at early rice and late rice growth seasons. Therefore, it was benefit practice for increasing soil carbon sequestration and improving rice NUE in the double-cropping rice system with long-term application of rice straw and organic manure managements.

A novel immunochemotherapy based on immunogenicity-activated and immunosuppression-reversed biomimetic nanoparticles

Studies show that infiltrated myeloid-derived suppressor cells (MDSCs) are vital in the immunosuppressive tumor microenvironment and account for lymphoma refractoriness and recurrence. Here, we developed a biomimetic nanoplatform (PM-PLGA-DOX/GEM) in which platelet membranes (PM) wrap PLGA nanoparticles co-loaded with doxorubicin (DOX) and gemcitabine (GEM). PM-PLGA-DOX/GEM would accumulate in tumor tissues because of the enhanced permeation and retention (EPR) effect and the tumor cell-induced platelet aggregation (TCIPA) effect. GEM could eliminate the MDSCs in tumor tissues, thereby reversing the immunosuppressive tumor microenvironment. Furthermore, DOX could invoke the immunogenic cell death (ICD) of lymphoma cells. Consequently, numerous T cells were recruited and activated to improve the therapeutic effects. This study will offer a potential platform for clinical treatment of lymphoma and other solid tumors.

Serum biomarkers for liver fibrosis

Liver fibrosis is a common pathway in most chronic liver diseases, characterized by excessive extracellular matrix accumulation. Without treatment, fibrosis will ultimately result in cirrhosis, portal hypertension, and even liver failure. It is considered that liver fibrosis is reversible while cirrhosis is not, making it significant to diagnose and evaluate liver fibrogenesis timely. As the gold standard, liver biopsy is imperfect due to its invasiveness and sampling error. Therefore, attempts at uncovering noninvasive tests have become a hot topic in liver fibrosis. Nowadays, as an important category of noninvasive tests, serum biomarkers, which are safer, convenient, repeatable, and more acceptable, are widely discussed and commonly used in clinical practice. Serum biomarkers of liver fibrosis can be divided into class I (direct) and classⅡ (indirect) markers. However, the diagnostic efficiency still varies among studies. This article summarizes the most established and newly discovered serum biomarkers for hepatic fibrogenesis.

Study Protocol of an App-Based Prevention Program for Perinatal Depression

The prevalence of perinatal depression (PND) in China is continuously rising, and the suicide rate among pregnant women is remarkably high. Preventing the occurrence of PND based on the management of primary health care is of great significance. Improving adherence to intervention programs is a key concern for PND prevention. Thus, a new intervention strategy based on mobile health could bring a new perspective to prevent the occurrence of PND and reduce the sample dropout rate. A single-blind, cluster randomized controlled trial will be performed to evaluate the effectiveness of a personalized, dynamic, and stratified intervention strategy based on an app. Four health centers will be randomly selected and randomly assigned to an intervention group (two centers) and a control group (two centers). Participants (n = 426) will be enrolled from the four selected health centers, with 213 in each group. The intervention group will receive the interventions personalized by the feature-matching algorithm of the user profile and be reassigned to the low-risk group (Edinburgh Postnatal Depression Scale [EPDS] < 9) or moderate/high-risk group (9 ≤ EPDS < 13 and EPDS ≥ 13, but not meeting the criteria for PND) for intervention based on each EPDS score until 6 months after delivery. The control group will receive the same intervention components of the app but without the dynamic, personalized, and stratified function. Depression status, negative emotion symptoms, parental competence, and sample dropout rate will be measured at different weeks of pregnancy (12-16 [baseline], 24, 37) and at 42 days, 3 months, and 6 months after delivery. Follow-up evaluation (t₆: 12 months after delivery) will also be conducted. If the intervention is effective, it will provide a personalized, time-friendly, and dynamic intervention for preventing PND. This phenomenon can effectively reduce the sample dropout rate and provide an empirical basis for promoting maternal mental health.

Changes of phosphorus species during (hydro) thermal treatments of iron-rich sludge and their solubilization mediated by a phosphate solubilizing microorganism

This study systematically evaluated phosphorus (P) solubilization from pyrochar and hydrochar derived from both raw sludge and iron-rich sludge. The data indicated, that an increase in thermal treatment temperature and the presence of iron promoted the accumulation of P in both pyrochar (derived at 300, 500, and 800 °C) and hydrochar (derived at 100, 200, and 280 °C). After incubating pyrochar and hydrochar with a phosphate solubilizing microorganism (PSM) (Pseudomonas aeruginosa) for 30 days, PSM significantly promoted the solubilization of P in pyrochar and hydrochar synthesized at low temperatures rather than those at high temperatures, with a 59 % increase for the pyrolysis of raw sludge at 300 °C than that pyrolyzed at 800 °C and a 62 % increase for the hydrothermal treatment of raw sludge at 100 °C than that treated at 280 °C. And the phenomena were more obvious on the char samples derived from iron-rich sludge. The mass balance of different P species in the solid and liquid phases indicated that after incubating with PSM for 30 days, NaOH-P was the main P solubilized from the solid phase of pyrochar and HCl-P was the main P solubilized from the solid phase of hydrochar. Considering P availability to plants, the preliminary economic analysis indicated that the hydrothermal treatment of iron-rich sludge at 100 °C showed the highest economic benefits for P recovery, with the net cost of 28.79 USD/ton wet sludge. This study was useful in giving novel insights into the reuse of char samples as P fertilizer, and also suggested the importance of Pseudomonas aeruginosa and other bacteria in sludge application, particularly in terms of P solubilization.

OS10.4.A A macrophage-based drug delivery platform for glioma treatment

Background

There is an urgent need for more effective treatment strategies against gliomas. At present, even though various drugs have potent anti-tumor activity in vitro, their application in vivo is limited by ineffective delivery and systemic toxicity. Therefore, novel strategies are needed to deliver these drugs effectively and safely to the tumor site. Here, we developed an adoptive transfer strategy against malignant brain tumors utilizing macrophages that are loaded with ferritin-protein cages containing drugs or other proteins and transfer these nanocarriers to cancer cells in vitro and in vivo.

Material and Methods

Live-time imaging, microscopy and flow cytometry were utilized to investigate the transfer of ferritin cages from loaded macrophages to human or mouse glioma cells. Co-cultures of glioma cells and macrophages loaded with ferritin-drug cages were used to study the anti-glioma activity in vitro and orthotopic immunocompetent mouse glioma models were used to study the anti-glioma activity in vivo. Affinity purification-mass spectrometry (AP-MS) was used to elucidate the mechanisms of transfer by characterizing the interactome of ferritin cages within macrophages and cancer cells.

Results

We observed a high transfer efficiency of ferritin-cages from loaded macrophages into human and mouse glioma cells in vitro in co-culture assays and confirmed the transfer from macrophages to glioma cells also in vivo upon intravenous or intratumoral treatment of GL-261 or CT-2A glioma-bearing mice. To study the anti-glioma activity with therapeutically active payloads, we loaded murine/human macrophages with ferritin cages carrying cytotoxic payloads. Co-culture of these loaded macrophages with murine or human glioma cells in vitro revealed a time- and concentration-dependent cytotoxicity to glioma cells. In vivo, intravenous or intratumoral administration of ferritin-drug protein cages was tolerated without toxicities and conferred a survival benefit in two orthotopic murine glioma models (GL-261 and CT-2A). Interactome studies of ferritin-cage-binding proteins revealed phagocytic and cytoskeleton re-arrangement pathways to be involved in uptake and transfer of ferritin-cages from macrophages to glioma cells.

Conclusion

This ‘Trojan Horse’ approach constitutes a promising platform to deliver cytotoxic drugs effectively and safely to gliomas and provides a rationale for clinical translation.

Swollen inguinal lymph nodes with low fever and night sweat: diagnosis and treatment of case of cat-scratch disease lymphadenitis with sinus formation

A 52-year-old woman complained of inguinal lymph node enlargement, low fever and night sweats for 20 days. After pathological biopsy and metagenomic sequencing, she was diagnosed as having Bartonella henselae infection. Her lymph nodes were accompanied by multiple ulcers in the affected area and sinus formation. Azithromycin was administered according to the Sanford Guide to Antimicrobial Therapy 2020, combined with wound repair and partial resection of inguinal lymph nodes. The patient showed good recovery after the operation. In all, lymphadenitis associated with B. henselae infection is difficult to diagnose. Lymphadenitis with suppuration and sinus formation needs multidisciplinary consultation. When the causal pathogen is unknown, metagenomic sequencing is recommended for a definite diagnosis.

Clinical Monitoring of Serum Levels of Vitamins A, D and E in Children with Recurrent Respiratory Tract Infections of Different Ages: A Clinical Controlled Trial

Objective

To study serum levels of vitamins A, D and E in children with recurrent respiratory tract infections of different ages and the correlation.

Methods

The clinical data of two groups of children of different ages were collected. The serum levels and deficiencies of vitamins A, D and E in children were statistically analyzed.

Results

The proportions of premature infants, low body weight infants, special physique, hospitalization history, hypocalcemia, living in a bungalow, and daily outdoor activities in less than 30 minutes in the case group were higher than those in the control group (χ²=4.507, 5.165, 7.040, 14.907, 4.267, 33.800, 4.507, 8.571, P < 0.05). The serum levels of vitamins A, D and E of children aged 0–1, 2–5, and 6–12 in the case group were lower than those in the control group (P < 0.05). Compared with the control group, the serum vitamin A level of children in the case group was lower (t = 2.631, P < 0.05), and the deficiency rate was higher (χ²=24.200, P < 0.05).

Conclusion

Serum levels of vitamins A, D and E, which are related to birth mode, physical fitness, hospitalization history, hypocalcemia, vitamin deficiency, living environment, and daily outdoor activity time, vary in children with recurrent respiratory tract infections of different ages, and are lower in children with recurrent respiratory tract infections than in healthy children.