Factors associated with regular HIV testing behavior of MSM in China: a cross-sectional survey informed by theory of triadic influence

The prevalence of HIV infection among men who have sex with men (MSM) in China has increased in recent years. Regular HIV testing is a key prevention strategy for identifying HIV infections among MSM. Informed by the theory of triadic influence, we aimed to determine individual, social and environmental factors associated with regular HIV testing behavior. Regular HIV testing is defined as taking an HIV test every 3 to 6 months. Both an online survey and a face-to-face survey was administered to MSM in China. Logistic regression was used to examine associations with testing behavior. 500 MSM were surveyed, the prevalence of regular testing was 56.4%. In the final model, age of first sexual intercourse, self-efficacy, perceived risk, number of partners, orientation disclosure, knowledge of HIV testing, behavioral intention and HIV relevant behaviors (sexually transmitted infection testing history) were associated with regular HIV testing; social stream characteristics had stronger associations with regular testing than individual and environmental factors. Findings implicated that interventions aimed at improving the effective counseling service from healthcare providers and the medical environment and intrapersonal changes should be combined to encourage MSM to have their first HIV test and to keep coming back at regular intervals.

Superior rectal artery embolization for bleeding internal hemorrhoids

BACKGROUND

The aim of the present study was to evaluate clinical efficacy and safety of superselective embolization of the superior rectal artery (SRA) for the treatment of internal hemorrhoidal bleeding.

METHODS

Patients with stage II and stage III internal hemorrhoids, treated by interventional embolization of the SRA in our department between January 2017 and June 2019 were retrospectively evaluated. All patients suffering from disabling chronic hematochezia and some with relative contraindications for operation (n = 17) or rejection of conventional hemorrhoidectomy (n = 15). Superselective SRA branch embolization was performed using gelatin sponge particles (350-560 μm) and metallic coils (2-3 mm). This treatment process was planned by a multidisciplinary team consisting of proctologist, gastroenterologist and radiologist. The surgical efficacy, postoperative complications and follow-up outcomes were observed.

RESULTS

There were 32 patients (18 males, mean age 52 ± 12 years, range: 22-78 years), 12 (37%) with stage II hemorrhoids and 20 (63%) with stage III hemorrhoids. Embolization was successful in all patients, and bleeding symptoms resolved in 27 (84.4%) patients. The remaining 5 (15.6%) patients underwent either stapled hemorrhoidopexy (n = 4) or sclerotherapy (n = 1). Some patients experienced different degrees of pain (n = 4;12.5%), low fever (n = 11;34.4%), and tenesmus (n = 17;53.1%), which all spontaneously regressed without further treatment. All patients were followed up for at least 1 year. There were no serious complications, such as infection, intestinal ischemia or massive hemorrhage. Four patients (14.8%) had rebleeding during the first months of follow-up. All patients with re-bleeding were successfully treated with internal iliac arteriography and branch embolization and did not experience further bleeds after a minimum follow up 3 months follow-up.

CONCLUSIONS

The short-term efficacy of superselective SRA embolization for grade II-III internal hemorrhoids is good, and this method is safe and feasible.

Effects of Agaricus blazei Murrill polysaccharides on hyperlipidemic rats by regulation of intestinal microflora

The present research envisaged the effects of Agaricus blazei Murrill polysaccharides (ABPs) on blood lipids and its role in regulation of the intestinal microflora in hyperlipidemic rats. The acidic polysaccharide fraction of Agaricus blazei Murrill was obtained by DEAE-cellulose ion exchange column chromatography. The sugar content of ABP was 75.1%. Compared with the model group (MG), the serum TC, TG, and LDL-C levels decreased (p < .05 or p < .01) and the HDL-C levels increased (p < .01) significantly in the ABP group. Expression of CYP7A1 was up-regulated (p < .01), and that of SREBP-1C (p < .05) was down-regulated significantly in the liver tissue of rats in the ABP group. Additionally, the disordered hepatic lobules and the steatosis of hepatocytes were found to be significantly alleviated in the ABP group. We believe that ABP can reduce the ratio of Firmicutes/Bacteroidetes and reduce the relative abundance of Firmicutes, Ruminococcaceae_unclassified, and Ruminococcaceae, increasing the relative abundance of Proteobacteria, Clostridium_sensu_stricto, Allobaculum, Peptostreptococcaceae, Clostridiaceae_1, and Erysipelotrichaceae as targets to regulate blood lipids. The results showed ABP could regulate the dyslipidemia in rats with hyperlipidemia. The mechanism may be through the regulation of the imbalance of intestinal microflora induced by the high-fat diet in rats, which may be one of the important ways of its intervention on the dyslipidemia induced by high-fat diet.

Acropetal translocation of phenanthrene in wheat seedlings: Xylem or phloem pathway?

Due to the potential toxicity of polycyclic aromatic hydrocarbons (PAHs) to humans, the uptake and translocation of PAHs in food crops have gained much attention. However, it is still unclear whether phloem participates in the acropetal translocation of PAHs in plants. Herein, the evidence for acropetal translocation of phenanthrene (a model PAH) via phloem is firstly tested. Wheat (Triticum aestivum L.) new leaves contain significantly higher phenanthrene concentration than old leaves (P < 0.05), and the inhibitory effect on phenanthrene translocation is stronger in old leaves after abscisic acid and polyvinyl alcohol (two common transpiration inhibitors) application. Phenanthrene concentration in xylem sap is slightly higher than in phloem sap. Ring-girdling treatment can significantly reduce phenanthrene concentration in castor bean (Ricinus communis L.) leaves. Two-photon fluorescence microscope images indicate a xylem-to-phloem and acropetal phloem translocation of phenanthrene in castor bean stem. Therefore, phloem is involved in the acropetal translocation of phenanthrene in wheat seedlings, especially when the xylem is not mature enough in scattered vascular bundle plants. Our results provide a deeper understanding of PAH translocation in plants, which have significant implications for food safety and phytoremediation enhancement of PAH-contaminated soil and water.

Isolation and purification of acidic polysaccharides from Agaricus blazei Murill and evaluation of their lipid-lowering mechanism

Polysaccharides are important active constituents of Agaricus blazei Morrill. In the present study, WABM-A was isolated from WABM using DEAE-cellulose, and subsequently purified using sepharose CL-6B to obtain the acidic polysaccharide WABM-A-b. WABM-A-b is mainly composed of Glc dextran, with a molecular weight of 10 KDa and β-1,6-D-Glcp as its main chain. The results of in vivo experiments show that in comparison with the MG, WABM-A significantly reduced the serum levels of TC, TG, and LDL-C, increased the serum levels of HDL-C (P < 0.01), and upregulated the liver expression of PPARγ, LXRα, ABCA1, and ABCG1 in rats with hyperlipidemia (P < 0.05). The results of in vitro experiments show that in comparison with the MG group, WABM-A-b-H significantly reduced the levels of TC and TG in HepG2 cells induced by oleic acid (P < 0.01), and significantly upregulated the protein expression of PPARγ, LXRα, ABCA1, and ABCG1 (P < 0.05). The present study demonstrates that WABM-A-b is an acidic glucan with lipid-lowering activity. The lipid-lowering mechanism of WABM-A-b is via the activation of the PPARγ/LXRα/ABCA1/ABCG1 cholesterol metabolism pathway. This is the first time that the hypolipidemic effect of Agaricus blazei Morrill acidic polysaccharides has been reported.

Deterministic Magnetization Switching Using Lateral Spin-Orbit Torque

Current-induced magnetization switching by spin-orbit torque (SOT) holds considerable promise for next generation ultralow-power memory and logic applications. In most cases, generation of spin-orbit torques has relied on an external injection of out-of-plane spin currents into the magnetic layer, while an external magnetic field along the electric current direction is generally required for realizing deterministic switching by SOT. Here, deterministic current-induced SOT full magnetization switching by lateral spin-orbit torque in zero external magnetic field is reported. The Pt/Co/Pt magnetic structure is locally annealed by a laser track along the in-plane current direction, resulting in a lateral Pt gradient within the ferromagnetic layer, as confirmed by microstructure and chemical composition analysis. In zero magnetic field, the direction of the deterministic current-induced magnetization switching depends on the location of the laser track, but shows no dependence on the net polarization of external out-of-plane spin currents. From the behavior under external magnetic fields, two independent mechanisms giving rise to SOT are identified, i.e., the lateral Pt-Co asymmetry as well as out-of-plane injected spin currents, where the polarization and the magnitude of the SOT in the former case depends on the relative location and the laser power of the annealing track.

Atomic origin of spin-valve magnetoresistance at the SrRuO3 grain boundary

Defects exist ubiquitously in crystal materials, and usually exhibit a very different nature from the bulk matrix. Hence, their presence can have significant impacts on the properties of devices. Although it is well accepted that the properties of defects are determined by their unique atomic environments, the precise knowledge of such relationships is far from clear for most oxides because of the complexity of defects and difficulties in characterization. Here, we fabricate a 36.8° SrRuO3 grain boundary of which the transport measurements show a spin-valve magnetoresistance. We identify its atomic arrangement, including oxygen, using scanning transmission electron microscopy and spectroscopy. Based on the as-obtained atomic structure, the density functional theory calculations suggest that the spin-valve magnetoresistance occurs because of dramatically reduced magnetic moments at the boundary. The ability to manipulate magnetic properties at the nanometer scale via defect control allows new strategies to design magnetic/electronic devices with low-dimensional magnetic order.

Cyclophosphamide induces a significant increase in iron content in the liver and spleen of mice

Objective:

Oxidative stress is one of the major mechanisms of cyclophosphamide (CPX)-induced toxicities. However, it is unknown how CPX induces oxidative stress. Based on the available information, we speculated that CPX could increase iron content in the tissues and then induce oxidative stress.

Method:

We tested this hypothesis by investigating the effects of CPX on iron and ferritin contents, expression of transferrin receptor 1 (TfR1), ferroportin 1 (Fpn1), iron regulatory proteins (IRPs), hepcidin, and nuclear factor erythroid 2-related factor-2 (Nrf2) in the liver and spleen, and also on reticulocyte count, immature reticulocyte fraction, and hemoglobin (Hb) in the blood in c57/B6 mouse.

Results:

We demonstrated that CPX could induce a significant increase in iron contents and ferritin expression in the liver and spleen, notably inhibit erythropoiesis and Hb synthesis and lead to a reduction in iron usage. The reduced expression in TfR1 and Fpn1 is a secondary effect of CPX-induced iron accumulation in the liver and spleen and also partly associated with the suppressed IRP/iron-responsive element system, upregulation of hepcidin, and downregulation of Nrf2.

Conclusions:

The reduced iron usage is one of the causes for iron overload in the liver and spleen and the increased tissue iron might be one of the mechanisms for CPX to induce oxidative stress and toxicities.

The role of temperature in phenanthrene transfer and accumulation in crop leaves

Polycyclic aromatic hydrocarbons (PAHs) pollution has become a worldwide environmental problem, and the spread of PAHs can cause carcinogenicity, mutagenicity, and toxicity to humans. However, the transfer and accumulation of PAHs in crop leaves has not been clearly understood. In this study, we first reported that the environmental temperature could induce phenanthrene transfer and accumulation in hydrocultured wheat, corn and soybean leaves via vacuum-infiltration-centrifugation method. Phenanthrene accumulation rises significantly (p < 0.05) in the first 8 h and reaches the maximum accumulation rate at the 4th h. Then the accumulation turns stable in both apoplast and sympalst of wheat, soybean and corn leaves. Temperature is positively correlated with phenanthrene accumulation in apoplast and sympalst of soybean and corn leaves, and phenanthrene accumulation increases under lower temperature in apoplast and sympalst of wheat leaves. Temperature also displays a positive correlation with the phenanthrene accumulation under gradient phenanthrene treatments in both apoplast and sympalst. In addition, the wheat, corn and soybean leaves have the same phenanthrene accumulation pathways and symplast pathway is major for phenanthrene accumulation with the contribution over 55% in total phenanthrene accumulation. Meanwhile, based on the Elovich equation, the symplast and apoplast processes of phenanthrene accumulation are endothermic. In the end, our findings will offer a new understanding for phenanthrene transfer and accumulation pathway in plant leaves and put forward a new biological reference of PAHs transfer in environmental science.

Preparation of Superhydrophobic Porous SiO₂ Aerogel Using Methyl Trimethoxy Silane Single Precursor and Superhydrophobic Cotton Fabric Coating from It

Superhydrophobic cotton fabrics were prepared by simultaneous incorporation of SiO₂ aerogel particles and polydimethylsiloxane (PDMS). The SiO₂ aerogels were synthesized via acid-base catalyzed sol-gel reaction with methyl trimethoxy silane (MTMS) as the single precursor and oxalic acid and ammonium hydroxide as the catalyst in methanol (MeOH) solution by drying under ambient pressure. The preparation parameters (e.g., MTMS/MeOH molar ratio, oxalic acid/MTMS molar ratio, gelation pH value, and gelation temperature) had great influences on the density and porosity of the SiO₂ aerogel. The obtained SiO₂ aerogel had low density, high porosity and high specific surface area, showing the typical rough mesoporous structure. The prepared bulk SiO₂ aerogel displayed excellent superhydrophobicity with a water contact angle (WCA) of 151.0 ± 0.8°. Superhydrophobic cotton fabric with a WCA of 155.6 ± 0.9° for a 5 μL water droplet was successfully obtained by simply coating the PDMS/SiO₂ aerogel composite solution via dip-pad-cure process. This could be attributed to the combination of SiO₂ aerogel particles with porous rough microstructure, high specific surface area and PDMS adhesive layer with low surface energy. The effect of PDMS/SiO₂ aerogel coating treatment on the mechanical strength properties of the cotton fabrics was negligible. This simple approach may pave the potential way for practical applications.

Differences in social isolation between young and old elderly in urban areas of Beijing, China: A cross-sectional study

Objectives

To understand the differences in social isolation among older adults and to identify risks associated with social isolation.

Methods

Totally 485 participants aged 60 and older were recruited for this study. The Lubben Social Network Scale-6 and the Chinese version of the Medical Outcomes Study Social Support Survey were used to measure social isolation and the different types of social support that the participants experienced.

Results

The proportions of young elderly (60–74 years of age) and old elderly (greater than 74 years of age) that experienced social isolation in this study were 24.4% and 33.1%, respectively. For the young elderly, three types of social support were observed to be protective factors to help avoid social isolation, and the positive effect of social support obtained from friends and neighbors was slightly stronger than that of family members. Old elderly with only a senior high school education background were at high risk of being socially isolated. Only support from friends was observed to be a protective factor for the old elderly.

Conclusions

The study indicated that different ages of older adults experienced different aspects of social relationships. We propose that nursing interventions for the elderly should focus on individualized social support as a protective factor to help older adults avoid being socially isolated.

Effect of Different Sources Support on Adaptation in Families of Patient With Moderate-to-Severe Dementia in China

PURPOSE

To examine the support from different sources of Chinese families of patients with moderate-to-severe dementia that most heavily influences the family adaptation and the influence pathway.

METHOD

Two hundred and three families participated in this study. Chinese versions of instruments were used. Structural equation modeling was applied to confirm the effect pathway.

RESULTS

More family support, kin support, community support, and social support (narrow sense) were related to greater levels of family adaptation. Family support was the most heavy influence factor (total effect = 0.374), followed by kin support (0.334), social support (0.137), and community support (0.121). Family support and kin support were direct influence factors, while the other 2 were not.

CONCLUSION

All support will promote family adaptation, especially family support and kin support. Interventions improving support from different sources, especially family support and kin support, will promote adaptation in Chinese families of patients with moderate-to-severe dementia.

Social support network, social support, self-efficacy, health-promoting behavior and healthy aging among older adults: A pathway analysis

AIMS

To determine the pattern of relationships among social support network, social support, self-efficacy, health-promoting behavior and healthy aging in older adults.

METHODS

Totally, 485 community-dwelling participants aged 60 years and older were recruited from four districts of Beijing, China. Data were obtained from July to November, 2017 using a questionnaire containing general information items, the Lubben Social Network Scale-18, the Medical Outcomes Study Social Support Survey-Chinese version, the Self-rated Abilities for Health Practices Scale, the Health-Promoting Lifestyle Profile II and a Healthy Aging Instrument. Path analysis was applied to examine the pattern of relationships between one's social support network and healthy aging.

RESULTS

The influence of a neighbor network on healthy aging was stronger than that of a family and friend network. Friend network had greater impact than family network on health-promoting behavior and self-efficacy. However, support from family members had a stronger effect than friend support and neighbor support on health-promoting behavior, self-efficacy and healthy aging. Furthermore, the finding revealed that self-efficacy had the stronger effect on healthy aging than that of health-promoting behavior.

CONCLUSION

These findings demonstrate that one's social support network plays an important role in promoting healthy aging. In China, medical and human resources for community healthcare systems are often limited. We propose that community nurses, as the "gatekeepers" to the healthcare system, should actively collaborate with older adults' social network resources to promote healthy aging. Moreover, nurses should develop efficient programs which focus on the ways of improving self-efficacy.

Three-dimensional distribution of permafrost and responses to increasing air temperatures in the head waters of the Yellow River in High Asia

Fine-scale three-dimensional (3D) permafrost distributions at the basin scale are currently lacking. They are needed to monitor climate and ecosystem change and for the maintenance of infrastructure in cold regions. This paper determined the horizontal and vertical distributions of permafrost and its quantitative responses to climate warming in the High Asia region by constructing a quasi-3D model that couples heat transfer and water movement and is forced by spatially-interpolated air temperatures using an elevation-dependent regression method. Four air temperature scenarios were considered: the present state and air temperature increases of 1, 2 and 3 °C. A fine-scale permafrost map was constructed. The map considered taliks and local factors including elevation, slope and aspect, and agreed well with field observations. Permafrost will experience severe degradation with climate warming, with decreases in area of 36% per degree increase in air temperature, increases in the depth-to-permafrost table of 2.67 m per degree increase in air temperature, and increases in 15 m-depth ground temperatures of 1.25 °C per degree increase in air temperature. Permafrost is more vulnerable in and beside river valleys than in high mountains, and on sunny rather than shady slopes. These results provide an effective reference for permafrost prediction and infrastructure and ecosystem management in cold regions affected by global warming.

Activation of CXCL6/CXCR1/2 Axis Promotes the Growth and Metastasis of Osteosarcoma Cells in vitro and in vivo

Osteosarcoma (OS) is a malignant primary bone tumor with high metastatic rate. C-X-C motif chemokine ligand 6 (CXCL6) and its receptor C-X-C motif chemokine receptor 1/2 (CXCR1/2) have been found to participate in the process of carcinogenesis. In this study, we evaluated the role of CXCL6/CXCR1/2 axis in proliferation and metastasis of OS cells. According to our results, the mRNA and protein expressions of CXCL6, CXCR1, and CXCR2 in multiple OS cell lines were determined. Treatment with exogenous CXCL6 for more than 72 h significantly promoted the proliferation of OS cells. Blocking the effect of endogenous CXCL6 restrained the migration, invasion and epithelial-mesenchymal transition (EMT) as evidenced by increased E-cadherin level, decreased N-cadherin and Snail levels in OS cells. On the contrary, exogenous CXCL6 administration enhanced the migration and invasive abilities of OS cells. Moreover, silencing of CXCR1/2 suppressed migration, invasion and EMT of OS cells with or without treatment with exogenous CXCL6. In addition, exogenous CXCL6 promoted the activation of PI3K/AKT and β-catenin signaling pathways, which could be repressed by CXCR2 knockdown. Inactivation of PI3K/AKT or β-catenin pathway by specific inhibitors effectively suppressed CXCL6-induced migration, invasion and EMT of OS cells. Finally, overexpression of CXCL6 significantly contributed to tumor growth, pulmonary metastasis and activation of PI3K/AKT and β-catenin pathways in nude mice in vivo, which were repressed by treatment with CXCR2 antagonist. Our results suggest that CXCL6/CXCR1/2 axis promotes the proliferation and metastasis of OS cells.