Stable Fe3O4 submicrospheres with SiO2 coating for heterogeneous Fenton-like reaction at alkaline condition

In the traditional Fenton process, the efficient generation of hydroxyl radical (HO) strongly relies on an acidic circumstance and the iron ions would precipitate and form large amounts of hazardous iron-containing sludge at alkaline pH. To realize stable heterogeneous Fenton-like catalytic degradation at alkaline condition, Fe₃O₄ submicrospheres with SiO₂ coating were successfully synthesized by using water glass as the silica sources via a facile ultrasound assisted method. The as-obtained Fe₃O₄@SiO₂ spheres were further used as catalysts for the Fenton-like degradation of tetracycline hydrochloride (TC). The Fe₃O₄@SiO₂ submicrospheres exhibited superior catalytic activity in higher pH environment (pH value = 11), and the degradation efficiency toward TC was ca. 80% after ten successive runs. The kinetics for the catalytic degradation of TC were agreed well with the second-order kinetic model. The reaction rate constant (k) over the Fe₃O₄@SiO₂ submicrospheres at a pH value of 11 was 7.69 times greater than that at a pH value of 3. Reactive species scavenging experiments revealed that HO and superoxide radical (O₂^- / HO₂^-) played a dominant role during the Fenton-like degradation of TC at pH 3 and pH 11, respectively. Possible Fenton-like degradation pathways of TC were proposed through the identification of intermediates using the high performance liquid chromatography coupled with mass spectrometry (HPLC-MS), which involved cleavage of methyl groups, N-dimethyl group, and hydroxy groups, ring-opening reaction, etc. The degradation efficiency of TC was close to 91.5% and total organic carbon (TOC) in solution was eliminated by about 41.4% at the optimized conditions. In a word, with the unique acidic surface properties and abundant Si-OH bonds, the Fe₃O₄@SiO₂ submicrospheres exhibited well dispersion, good catalytic activity, strong alkali resistance and excellent recyclability in an ultrasonic-Fenton-like system.

Investigations on the impact of the introduction of the Aloe vera into the hydrogel matrix on cytotoxic and hydrophilic properties of these systems considered as potential wound dressings

In the paper, synthesis of chitosan-based hydrogels modified with Aloe vera juice is presented. The novelty of the research was a combination of hydrogel materials with properties beneficial in viewpoint of their use as modern wound dressings and Aloe vera juice supporting the wound healing process. Hydrogels have been obtained via UV radiation. The impact of the amount of the crosslinking agent as well as the introduction of the Aloe vera juice into the hydrogel matrix has been determined. Performed measurements involved analysis of the swelling ability, characteristics of the surface roughness, determining the release profile of Aloe vera and the contact angles of hydrogels. Furthermore, the analysis of the dehydration process of the polymer membrane, investigations on the cytotoxicity of hydrogels via MTT reduction assay and the neutral red uptake assay as well as the studies on the pro-inflammatory activity have also been performed. It was proved that the addition of Aloe vera juice improves the hydrophilic properties of the materials (e.g. contact angle changed from 82.5° to 73.0°). Next, the use of 25% more of the crosslinker resulted even in the increase of the contact angle by 86%. Modified hydrogels showed higher swelling properties even by 15% than unmodified materials. Furthermore, obtained hydrogels show an ability to release Aloe vera - after 5 h approx. 80% of this additive has been released in an acidic environment. Tested materials do not exhibit cytotoxic properties, the addition of Aloe vera results in an improvement of the viability of L929 murine fibroblasts and, importantly, these materials show lower pro-inflammatory activity than the positive control. Performed investigations allow to state that obtained materials show a great application potential.

Infestation and distribution of chigger mites on Brown rat (Rattus norvegicus) in Yunnan Province, Southwest China

Chigger mites is a group of arthropods and some of them are vectors of scrub typhus. As a common synanthropic rodent species, the Brown rat (Rattus norvegicus) often harbors lots of ectoparasites including chigger mites. According to some "data mining" strategies, the present study took the advantage of the abundant original data from a long-term field ecological investigation between 2001 and 2015 to make a detailed analysis of chigger mites on R. norvegicus in Yunnan Province, Southwest of China. From 18 of 33 investigated counties, only 1414 chigger mites were collected from 1113 Brown rats with relatively low infestations. The 1414 individual chigger mites were identified as comprising 61 species, 11 genera and 2 subfamilies of the family Trombiculidae with a high species diversity (S=61, H'=3.13). Of 61 mite species, there were four main species, Walchia ewingi, Ascoschoengastia indica, W. koi and A. rattinorvegici, which accounted for 44.41% of the total mites. All the chigger mites were of aggregated distribution among different individuals of R. norvegicus. The Brown rats in the outdoor habitats harbored much more individuals and species of chigger mites with a higher mean abundance (MA=1.46) and mean intensity (MI=12.53) than in the indoor habitats (P<0.05). The overall infestation of the rats was significantly higher in the mountainous landscapes than in the flatland landscapes (P<0.001). The species similarity (C_ss) of the mites on the male and female rats reached 64.44% with sex biased infestations. The male rats harbored more species and individuals of the mites than the female rats. The adult rats harbored more species and individuals of the mites than the juvenile rats. The species abundance distribution of the mites was successfully fitted by Preston's lognormal model with ŝ(R)=15e^{-[0.31(R-1)]2} (α=0.31, R²=0.95). On the basis of fitting the theoretical curve by Preston's model, the total mite species on R. norvegicus was estimated to be 86 species, and 25 rare mite species were missed in the sampling field investigation. The curve tendency of the species-plot relationship indicates that R. norvegicus have a great potential to harbor many species of chigger mites, and more species of the mites would be collected if more rats are sampled.

Terahertz radiation generation from metallic electronic structure manipulated by inhomogeneous DC-fields

We propose a feasible, high-efficiency scheme of primary terahertz (THz) radiation source through manipulating electronic structure (ES) of a metallic film by targeted-designed DC-fields configuration. The DC magnetic field is designed to be of a spatially inhomogeneous strength profile, and its direction is designed to be normal to the film, and the direction of the DC electric field is parallel to the film. Strict quantum theory and numerical results indicate that the ES under such a field configuration will change from a 3D Fermi sphere into a highly-degenerate structure whose density-of-state curve has pseudogap near Fermi surface. Wavefunctions' shapes in this new ES are space-asymmetric, and the width of pseudogap near Fermi surface, as well as magnitudes of transition matrix element, can be handily controlled by adjusting parameter values of DC fields. Under available parameter values, the width of the pseudogap can be at milli-electron-volt level (corresponding to THz radiation frequency), and the magnitude of oscillating dipole can be at [Formula: see text]-level. In room-temperature environment, phonon in metal can pump the ES to achieve population inversion.

Expectations of reward and efficacy guide cognitive control allocation

The amount of mental effort we invest in a task is influenced by the reward we can expect if we perform that task well. However, some of the rewards that have the greatest potential for driving these efforts are partly determined by factors beyond one's control. In such cases, effort has more limited efficacy for obtaining rewards. According to the Expected Value of Control theory, people integrate information about the expected reward and efficacy of task performance to determine the expected value of control, and then adjust their control allocation (i.e., mental effort) accordingly. Here we test this theory's key behavioral and neural predictions. We show that participants invest more cognitive control when this control is more rewarding and more efficacious, and that these incentive components separately modulate EEG signatures of incentive evaluation and proactive control allocation. Our findings support the prediction that people combine expectations of reward and efficacy to determine how much effort to invest.

Programmed responses of different life-stages of the seagrass Ruppia sinensis to copper and cadmium exposure

Seagrass meadows are recognized as crucial and are among the most vulnerable habitats worldwide. The aquatic plant genus Ruppia is tolerant of a wide salinity range, and high concentrations of trace metals. However, the tolerance of its early life stages to such trace metal exposure is unclear. Thus, the current study investigated the trace metal-absorbing capacity of three different life-history stages of Ruppia sinensis, a species that is widely distributed in China, by observing toxic symptoms at the individual, subcellular, and transcription levels. The seedling period was the most vulnerable, with visible toxic effects at the individual level in response to 50 μM copper and 500 μM cadmium after 4 days of exposure. The highest concentrations of trace metals occurred in the vacuoles and cytoplasmic structures of aboveground tissues. Genes related to signal identification and protein processing were significantly downregulated after 4 days of exposure to copper and cadmium. These results provide information relating to the strategies evolved by R. sinensis to absorb and isolate trace elements, and highlight the phytoremediation potential of this species.

Different effects of probiotics and antibiotics on the composition of microbiota, SCFAs concentrations and FFAR2/3 mRNA expression in broiler chickens

AIMS

The aims of this study were to investigate the effects of probiotics and antibiotics on microbial composition, short chain fatty acids (SCFAs) concentration and free fatty acid receptor 2/3 (FFAR2/3) expression in boiler chickens.

METHODS AND RESULTS

A total of 150 1-day-old male broilers were randomly allocated into three groups, control (CON) group, probiotics (PB) group and antibiotics (ATB) group. Results indicated that PB improved the average body weight from 1 to 21 days and feed intake from 21 to 42 days (P < 0·05), while ATB improved the feed efficiency from 1 to 42 days (P < 0·05). Based on 16s rRNA sequencing, PB treatment increased the amount of kingdom bacteria, and the relative abundance of the main bacteria including acetate and butyrate producing bacteria of phylum Firmicutes, family Ruminococcaceae and genus Faecalibacterium. ATB treatment also increased the relative abundance of phylum Firmicutes, family Ruminococcaceae and Lachnospiraceae, however, it introduced some pathogenic bacteria, such as bacteria of family Rikenellaceae and Enterobacteriaceae. Gas chromatography and mass spectrometry (GC-MS) assay revealed that PB increased acetate and butyrate concentrations at both 21 and 42 days, and propionate at 42 days in the colorectum. Moreover qRT-PCR analysis showed PB treatment significantly activated the FFAR2/3 mRNA expressions. On the contrast, ATB treatment lowered the colorectal propionate at 21 days, and decreased acetate, propionate and butyrate concentrations at 42 days, accompanied with decreased FFAR2/3 mRNA expressions.

CONCLUSIONS

Compared to the CON birds, an enriched SCFAs producing bacteria with higher SCFAs contents and activated FFAR2/3 expressions are prominent features of PB birds. However, antibiotics treatment plays the reverse effect compared to PB treatment.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study brings a significant idea that less SCFAs concentration may be another reason why the antibiotics inhibit the immune system development and immunity of the body.

Differences in hypertension and prehypertension among people living with and without HIV in China: role of HIV infection and antiretroviral therapy

OBJECTIVES

Hypertension is a growing health concern in people living with HIV (PLWH). However, association between HIV infection and hypertension is equivocal.

METHODS

In all, 1472 PLWH and 2944 HIV-negative individuals frequency-matched by age and sex were derived from the baseline survey of Comparative HIV and Aging Research in Taizhou (CHART), China. Prehypertension was defined as systolic blood pressure (BP) of 120-139 mmHg and/or diastolic blood pressure of 80-89 mmHg.

RESULTS

Despite the fact that prevalence of hypertension was overall lower among PLWH than among HIV-negative people (21.1% vs. 29.1%, P < 0.001), it was similar at ages 18-29 (7.6% vs. 8.5%) and 30-44 years (17.1% vs. 18.5%) but significantly lower in PLWH at ages 45-59 (26.1% vs. 40.7%) and 60-75 years (37.1% vs. 57.3%). Prehypertension prevalence was consistently higher in PLWH across all age groups. In the model adjusting for traditional risk factors, HIV infection was associated with hypertension (adjusted odds ratio [aOR] = 1.27, 95% confidence interval: 1.04-1.55) and prehypertension (aOR = 1.77, 95% CI: 1.51-2.08), and attenuated after additional adjustment for abdominal obesity. Age-stratified analysis showed that these associations of HIV with hypertension were observed at ages 18-29 and 30-44 years and associations with prehypertension were observed at ages 18-29, 30-44 and 45-59 years only. Years since HIV diagnosis and stavudine use were the HIV-specific factors independently associated with hypertension or/and prehypertension.

CONCLUSIONS

HIV infection is independently associated with prehypertension and hypertension especially at younger ages, and this risk may increase as treatment becomes prolonged. Our findings reinforce the urgent necessity for active BP screening and control strategies be adopted for PLWH in China.

Long non-coding RNA MIR503HG serves as a tumor suppressor in non-small cell lung cancer mediated by wnt1

OBJECTIVE

The incidence and death rate of lung cancer has been rising year by year. Non-small cell lung cancer (NSCLC) seriously affects people's health and quality of life. This study was designed to explore the functional role of long-chain non-coding RNA (LncRNA) MIR503HG in the development of NSCLC.

PATIENTS AND METHODS

The quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) assay was conducted to access the expression level of MIR503HG in NSCLC cell lines and tissues. The Cell Counting Kit-8 (CCK-8) assay, colony formation assay, and flow cytometric analysis were performed to assess the ability of MIR503HG in regulating cell proliferation and apoptosis in NSCLC. Subsequently, Western blotting was used to detect the expression level of Wnt1 in NSCLC. Besides, in vivo tumorigenesis assay was performed in nude mice to examine the ability of MIR503HG in tumor formation.

RESULTS

MIR503HG was downregulated in NSCLC. CCK-8 assay and colony formation assay revealed that MIR503HG negatively regulated cell proliferation in NSLCL progression. In addition, MIR503HG promoted cell apoptosis and suppressed cell cycle progression in NSCLC in vitro. MIR503HG inhibited tumor formation in nude mice bearing NSCLC in vivo. MIR503HG downregulated Wnt1 expression in NSCLC.

CONCLUSIONS

Lon non-coding RNA MIR503HG was downregulated in NSCLC. The over-expression of MIR503HG suppressed cell proliferation and promoted cell apoptosis in vitro and repressed tumorigenesis in vivo. MIR503HG suppressed NSCLC progression via negatively regulating Wnt1 expression.

[Epidemiological study of occupational diseases in Shenzhen City, China in 2006~2017]

Objective: To study the epidemiological characteristics of occupational diseases in Shenzhen City, China in 2006-2017, and to provide a scientific basis for prevention and control of occupational diseases. Methods: Cases of occupational diseases in 2006-2017 were collected from the Information System of Occupational Diseases and Occupational Health. A statistical analysis was performed to identify the characteristics of the disease distribution in terms of spectrum of disease, year, area, industry, type of economy and enterprise scale. Results: A total of 1673 cases of occupational disease (64 types, 8 classes) were diagnosed and reported in 2006-2017, chemical poisoning (31.50%) , ear, nose and throat diseases (28.21%) , and pneumoconiosis and other respiratory diseases (21.34%) were the most three commonest occupational diseases. The constituent of ratio of ear, nose and throat diseases and occupational diseases caused by physical factors increased in turn, the constituent of chemical poisoning, pneumoconiosis and other respiratory diseases, and skin disease reduced in turn, which all showed the difference was statistically significant (P<0.01) . Occupational diseases were often seen in districts of Baoan, Longgang, Longhua and Pingshan, as well as in private economy and small enterprise, mainly occurred in manufacturing industry. Conclusion: The incidence of occupational diseases increased steadily in 2006-2017, and we need to strengthen common occupational diseases, especially occupational noise-induced hearing loss, pay attention to districts of Baoan, Longgang, Longhua and Pingshan, as well as private economy and small enterprise.

[Effect of imatinib on the height of children with chronic myeloid leukemia in the chronic phase]

目的

评估伊马替尼对慢性髓性白血病慢性期（CML-CP）儿童身高的影响。

方法

2018年7月至2019年7月，在全国范围内对诊断时年龄<18周岁、接受伊马替尼治疗至少3个月的CML儿童或其家长发放问卷，调查受访者伊马替尼治疗前后身高的变化。主要评价指标为身高标准差积分值（HtSDS）以及标准差积分的差值（ΔHtSDS），并分析其相关影响因素。

结果

共有238例受访者符合标准并被纳入研究，男性138例（58.0％），初诊时中位年龄11.0（1.4～17.9）岁，青春期前93例（39.0％），至填写答卷时，中位年龄15.0（2.0～34.0）岁，中位伊马替尼服药时间28（3～213）个月。受访者填写答卷时HtSDS（−0.063±1.361）较治疗前HtSDS（0.391±1.244）显著下降（P<0.001），71.0％的患儿出现身高增长减慢。青春期前服药者治疗后HtSDS下降显著（P<0.05），而青春期开始后服药者HtSDS变化不明显（P>0.05）。多因素分析显示，服药初始年龄较小（偏回归系数为0.122，B＝0.572，t＝10.733，P<0.001）和服药时间较长（偏回归系数为−0.006，B＝−0.211，t＝−4.062，P<0.001）是伊马替尼抑制身高增长的独立影响因素。

结论

伊马替尼引起CML-CP儿童身高增长障碍，服药初始年龄越小、服药时间越长，伊马替尼对身高的影响越明显。