The contrasting relationships of relative humidity with influenza A and B in a humid subtropical region.

Influenza is an acute respiratory disease that seriously threatens public health. The occurrence of influenza has been proved to be related to a variety of meteorological factors. However, less attention has been paid to the effect of relative humidity (RH) on different types of influenza, especially in subtropical regions. Daily data on laboratory-confirmed influenza cases, weather variables, and air pollutants in Hefei covering the 2014-2019 period were collected. The seasonality and trend of daily influenza cases were explored by the time series seasonal decomposition method. Generalized linear model was fitted in conjunction with distributed lag nonlinear model to quantify the associations of RH with influenza A and influenza B. Subgroup analyses were conducted by sex, age (0-4, 5-17, and ≥18 years), and season (cold and warm seasons). A total of 5238 influenza cases including 2847 influenza A cases and 2391 influenza B cases were recorded. The epidemic of influenza presented a distinct seasonal pattern, and the number of daily influenza cases increased steadily since 2016. High RH was related to an increased risk of influenza A (maximum RR = 1.683, 95%CI: 1.365-2.076), especially among males, females, and school-age children. Low RH was associated with an increased risk of influenza B (maximum RR = 1.252, 95%CI: 1.169-1.340). The contrasting relationships of RH with influenza A and B remained significant in cold seasons. High RH and low RH were significantly associated with the increased risk of influenza A and B, respectively. The findings of our study may provide clues for proposing new effective interventions.

The association between diurnal temperature range and childhood bacillary dysentery.

Previous studies have found that mean, maximum, and minimum temperatures were associated with bacillary dysentery (BD). However, little is known about whether the within-day variation of temperature has any impact on bacillary dysentery. The current study aimed to identify the relationship between diurnal temperature range (DTR) and BD in Hefei, China. Daily data on BD counts among children aged 0-14 years from 1 January 2006 to 31 December 2012 were retrieved from Hefei Center for Disease Control and Prevention. Daily data on ambient temperature and relative humidity covering the same period were collected from the Hefei Bureau of Meteorology. A Poisson generalized linear regression model combined with a distributed lag non-linear model (DLNM) was used in the analysis after controlling the effects of season, long-term trends, mean temperature, and relative humidity. The results showed that there existed a statistically significant relationship between DTR and childhood BD. The DTR effect on childhood bacillary dysentery increased when DTR was over 8 °C. And it was greatest at 1-day lag, with an 8% (95% CI = 2.9-13.4%) increase of BD cases per 5 °C increment of DTR. Male children and children aged 0-5 years appeared to be more vulnerable to the DTR effect. The data indicate that large DTR may increase the incidence of childhood BD. Caregivers and health practitioners should be made aware of the potential threat posed by large DTR. Therefore, DTR should be taken into consideration when making targeted health policies and programs to protect children from being harmed by climate impacts.

[Effects of electromagnetic radiation on health and immune function of operators].

OBJECTIVE: To investigate the effects of electromagnetic radiation on the physiological indices and immune function of operators. METHODS: The general conditions and electromagnetic radiation awareness rate of 205 operators under electromagnetic radiation were evaluated using a self-designed questionnaire. Physical examination, electrocardiography, and routine urine test were performed in these operators. Peripheral blood was collected from the operators under electromagnetic radiation for blood cell counting and biochemical testing, and their peripheral blood lymphocytes were cultured for determination of chromosomal aberrant frequency and micronucleus frequency. The data from these operators (exposure group) were compared with those of 95 ordinary individuals (control group). RESULTS: The chief complaint of giddiness, tiredness, dizziness, and amnesia showed significant differences between the exposure group and control group (P < 0.01), and the difference in headache became larger with an increase in working years. The awareness rate of electromagnetic radiation damage was significantly higher in the exposure group than in the control group. The difference in bradycardia was significant between the two groups (P <0.01), and the incidence was higher with longer working years. Significant differences between the two groups were also found in the numbers of individuals with elevated alanine aminotransferase, total bilirubin, and direct bilirubin (P < 0.01), populations with increased lymphocyte ratio and decreased neutrophil ratio (P < 0.01), populations with positive occult blood, urobilinogen, and bilirubin tests, and the number of individuals with increased micronucleus frequency of cultured peripheral blood lymphocytes (P < 0.01). In addition, the exposure group had significantly increased complement C3 and C4 (P < 0.01), significantly increased IgG (P < 0.05), and significantly decreased IgM (P < 0.01), as compared with the control group. CONCLUSION: Electromagnetic radiation may lead to the changes in physiological indices, genetic effects, and immune function and affect the health and immune function in operators. The adverse effects are increased as the working years increase. So it is important to strengthen occupational protection of operators under electromagnetic radiation.

Growth response to ionic and osmotic stress of NaCl in salt-tolerant and salt-sensitive maize.

Salt-tolerant maize (STM) and salt-sensitive maize (SSM) were treated with 100 mM NaCl for 1, 3 and 6 d and the contents of Na+ and Cl(-) (cps) of different organelles of leaf cells determined by X-ray microanalysis. The results showed that Na+ and Cl(-) entered the cytoplasm, vacuole, chloroplast and apoplast simultaneously. When STM and SSM were treated in 100 mM NaCl at atmospheric pressure (-P) and with pressure equivalent to the osmotic pressure of the NaCl (+P), the dry weights of STM (+P) and SSM (+P) plants were greater than that of STM (-P) and SSM (-P) plants, showing that the inhibitory effect of salt on plant growth was at least partially due to the osmotic effect of the NaCl. When STM and SSM were treated with NaCl and iso-osmotic polyethlene glycol, the dry weights of plants given the iso-osmotic polyethlene glycol treatment were lower for both maize lines than that of the NaCl-treated plants. Our data show that under NaCl stress, both STM and SSM seedlings simultaneously suffered from osmotic and ion stresses.

Association between transforming growth factor-beta1 T869C polymorphism and rheumatoid arthritis: a meta-analysis.

OBJECTIVE: The results of studies on association between TGF-beta1 T869C polymorphism and susceptibility to RA are controversial. The absence of a replication of linkage might be due to different ethnicities. The aim of this study was to perform a preliminary investigation on the effect size of TGF-beta1 T869C polymorphism on RA susceptibility through a meta-analysis. METHODS: Case-control studies on the association of TGF-beta1 T869C with RA were searched up to March 2009, and the genotype frequencies in the control group were found to be consistent with the Hardy-Weinberg equilibrium. The effect summary odds ratio (OR) and 95% CIs were obtained. Publication bias was tested by funnel plot with Egger's regression test, and heterogeneity was assessed. RESULTS: Seven studies comprising 1122 cases and 1132 controls were included. Heterogeneity was observed (chi(2 )= 17.16; P = 0.009). Under the random effects model, the common OR was 1.38 (95% CI 0.95, 2.01; P = 0.09). In the subgroup meta-analysis, there was an association between TGF-beta1 T869C polymorphism and RA in the people of Asian descent (OR = 1.93; 95% CI 1.42, 2.62; P < 0.0001), but not in the people of non-Asian descent (OR = 0.88; 95% CI 0.65, 1.19; P = 0.41). There was no evidence of publication bias according to Funnel plot and Egger's regression test (a = 4.778; P = 0.14). CONCLUSIONS: There was heterogeneity between studies, and no clear evidence of an association on a worldwide population was observed. Subgroup analysis results suggest that TGF-beta1 T869C might play a role in RA susceptibility for Asians but not for non-Asians. Further studies are required for definite conclusions.

Self-concept and mental health status of 'stay-at-home' children in rural China.

AIM: To describe the self-concept and mental health status of 'stay-at-home' children and to explore the differences between stay-at-home children and non-stay-at-home children. METHODS: A cross-sectional survey was conducted in Changfeng County to collect information on self-concept and mental health status. Children were classified as 'stay-at-home' or 'non-stay-at-home' for data analysis. RESULTS: Stay-at-home children accounted for 55.1% of children. The two groups of children differed significantly on the total scores of self-concept (stay-at-home, 52.48 +/- 14.29; non-stay-at-home, 55.24 +/- 15.10). The mental health status of stay-at-home children was poor, with significant difference between them (stay-at-home, 41.17 +/- 12.25; non-stay-at-home, 40.14 +/- 13.11). Using multivariate linear regression analysis, we found that the total P-H score, gender, low family economic status, stay-at-home status and being cared for by an uncle/aunt or an older sibling were independent variables for mental health of the children. CONCLUSION: This study suggests that stay-at-home children have a greater risk of mental health problems than their counterparts in rural Anhui province, China. In addition, this study provides useful baseline information on childhood mental health and has identified important risk factors that would be important in planning strategies for prevention of mental health problems for stay-at-home children.

[Study on the distribution and risk factors of injuries among home-stranded children in rural area of Anhui province].

OBJECTIVE: To explore the distribution and risk factors of injuries among home-stranded children and living in rural area of Anhui province and to provide basic information for the development of injury intervention program. METHODS: 3617 students were recurited from Changfeng county of Anhui province with stratified sampling method and a survey was conducted using questionnaires. Unconditional univariate and multivariate logistic regression analysis were performed to evaluate the situation of unintentional injuries among 1614 home-stranded children during the past one year and on its influencing factors. RESULTS: The number of home-stranded children accounted for 45.83% of the total number of students with the main type of guardianship was single-parent (55.82%). The incidence of injuries of students was 32.25%. The incidence of injuries of boys (36.43%) was higher than that of girls (27.44%) (chi2 = 32.340, P = 0.000). The incidence of injuries among children was 32.25% but among children away from it was 40.90%, significantly higher than that of children with parents (24.95%) (chi2 = 101.730, P = 0.000). Seven kinds of injures including fall, transportation or animal-related factor for children who were away from their parents, were higher than that of children with parents around. Data from Univariate analysis showed that injuries of children without family around were associated with gender, monthly income, education level of mother, type of guardianship, introversion-extroversion, neuroticism, cohesion, conflict, independence, active-recreational orientation, intellectual-cultural orientation. Results from multivariate analysis indicated that injuries of home-stranded children were associated with gender (OR = 0.598), being the only child (OR = 1.445), introversion-extroversion (OR = 1.062), cohesion (OR = 0.933), conflict (OR = 1.150), independence (OR = 1.110), intellectual-cultural orientation (OR = 0.928), active-recreational orientation (OR = 1.096) and ability of self-control (OR = 0.917). CONCLUSION: Many factors were found to be involved in injuries among children who were away from parents, especially regarding family environment and the individual personality. Special preventive measures should be taken to reduce the incidence of injuries among rural children who were away from their parents.

[Effects of salt stress on the contents of chlorophyll and organic solutes in Aeluropus littoralis var. sinensis Debeaux].

After seedlings of Aeluropus sinensis var. sinensis Debeaux were treated with different NaCl concentrations (0-200 mmol/L) for 14 days, some physiological indexes were measured. The higher the NaCl concentration, the more the growth of A. sinensis was inhibited. The increase in root/shoot ratio suggests that the shoots are more sensitive to salinity than the roots. The diminished leaf area may reduce the transpiration rate, and the root mainly grew longitudinally, which may help the root to reach the water source under the high salinity conditions. Chl a contents increased, so did Chl b, but the Chl a/Chl b ratio declined, which implies the stimulation of Chl a accepted from NaCl is smaller than that of Chl b. After salt treatment, the organic solute contents increased (P<0.05), the proline, amino acids and soluble sugar contents increased more than organic acids, the increase in soluble carbohydrate may inhibit photosynthesis in feedback. The percentage of sucrose in soluble carbohydrates increased too. Although the organic dry weight of whole plant declined, the proportion of organic dry weight in total dry weight increased, and the osmotic potential of plant cell juice declined, which implies that the contribution of organic matter to osmotic adjustment increased with salinity. That is, A. sinensis had ability to tolerate salinity to a certain degree.

[The morphological structure of salt gland and salt secretion in Aeluropus littoralis var. sinensis Debeaux].

The leaves of Aeluropus littoralis var. sinensis Debeaux were scanned with a scanning electron microscope, it showed that the upper-epidermis had almost the same number of salt glands as the lower-epidermis (Plate I-1, 2), and the salt gland is the typical bicelluar gland, which consists of a large basal cell inlaid into the epidermis and a small cap cell (Plate I-6). These salt glands were distributed mainly on the leaf veins, which favors the rapid collection of salts from the roots. Ion X-ray microanalysis indicated that the salt glands could effectively absorb Na(+) from the epidermal cells and mesophyllous cells (Table 1), then secreted Na(+) from the cap cells (Plate I-4), which would decrease the salinity of plant. After the plants were treated with various salts for 17 d, the ion contents of the leaves and the secretion were measured, and the results implied that salt glands had different selection in absorbing and secreting Na(+) , K(+) and Ca(2+), that is, the plants first selected K(+) when absorbing ions, while first selected Na(+) when sending ions out, but Ca(2+) was fewer in both absorbed and secreted, and the order of secretion of the three ions was found to be Na(+)>K(+)>Ca(2+) (Figs. 1-6). The secretion of Na(+) or three ions were respectively higher than that of leaves within 24 h (Figs. 1, 2, 7, 8), while K(+) situation was completely opposite with them (Figs. 3, 4). At the same time, the total ion content and composition inside the leaves remained more or less constant (Fig. 8).

[Effects of salt stress on the growth and the nitrate reductase activity in Thellungiella halophila].

The results showed that when Thellungiella halophila was treated with NaCl, the fresh and dry weight, the water content, the succulency of whole plant and the root/shoot ratio were decreased (Figs. 2-4, 7); the organic matter content in roots was increased and the inorganic matter content in roots was decreased, while those in shoots changed in the opposite direction (Fig. 6); osmotic adjustment ability, the Na+ content, the root activity were increased (Figs. 5, 7, 8); the nitrate reductase activity increased significantly; the O(-)(2*) content decreased at about NaCl 50 mmol/L but increased at about NaCl 100-400 mmol/L (Fig. 10). The micrographs of T. halophila leaf surface by scanning electron microscope (SEM) indicate that there is no salt gland or bladder on the surface of T. halophila (Fig. 1), so it is not a salt-secreting halophyte. The determination of growth parameters, the Na(+) content and Na(+) X-ray (Table 1) microanalysis of T. halophila indicate that T. halophila is not a salt-exclusing halophyte but it probability is a salt-dilution halophyte.

[Osmotica accumulation and its role in osmotic adjustment in Thellungiella halophila under salt stress].

Thellungiella halophila was treated with different concentrations of NaCl (0, 50, 100, 200, 300 and 400 mmol/L). Water content, osmotic potential, various organic and inorganic osmotica contents in the leaves and roots were determined and the calculated osmotic potential (COP) of osmotica in the osmotic adjustment was calculated (Figs.1-10 and Table 1). The result showed that water content, osmotic potential decreased with the increase of salinity; Na(+) and Cl(-) were the accumulated inorganic osmotica in roots and leaves; soluble sugar, organic acid and free amino acid were the accumulated organic osmotica in roots; and proline was the accumulated organic osmotica in both root and leaf. Na(+) X-ray microanalysis indicated that vacuole in the cell was the main organelle of accumulation toxic ions (Table 2).

[Effects of salt stress on the growth and Na+ and K+ contents in Aeluropus littoralis var. sinensis Debeaux].

After seedlings of Aeluropus littoralis var. sinensis Debeaux were treated with different NaCl concentrations (0-200 mmol/L) for 17 days, some physiological indexs were measured. With an increase in NaCl concentration, the growth of A. littoralis was inhibited gradually. There was no optimum salt concentration, and the shoots were more sensitive than the roots. The proportion of organic dry weight in total dry weight increased, which implies that the contribution of organic matter to osmotic adjustment increased with salinity. After being treated with the inhibitor--benzene-sulphuric acid choline which could inhibit the salt glands to secrete the salinity outside the body. The Na(+) and K(+) contents of leaves increased, while the amount of Na(+) and K(+) decreased in the secretion, and the growth was severely inhibited. After being treated with NaCl 100 mmol/L, the relative Na(+) contents in the cap cells and basal cells determined by X-ray microanalysis were from about one to more than triple those of the epidermis and mesophyllous cells, it shows that the salt glands could effectively collect Na(+) from other cells and secrete them outside the body to keep normal physiological function.

[Effect of NaCl stress on ion compartmentation, photosynthesis and growth of Salicornia bigelovii Torr].

Seedlings of Salicornia bigelovii Torr. were treated with different concentrations of NaCl (0, 100, 300, 600 mmol/L). Ion contents, Na(+) subcelluar localization, photosynthetic rate, ultrastructure of chloroplast and other parameters were measured. The data showed both fresh and dry weight of whole plant of Salicornia bigelovii Torr. under salinity were higher than the control. When NaCl concentration is about 300 mmol/L Salicornia bigelovii Torr. grow strongest. The contents of Na(+) and Cl(-) and c(Na)/c(K) in shoots increased with the salinity. Both Na(+) and Cl(-) were mainly transported to shoots. Ion X-ray microanalysis indicated Na(+) was mainly compartmentalized into vacuoles. Photosynthetic rate increased with the salinity under NaCl 100-300 mmol/L, but declined under NaCl 600 mmol/L. Ultrastructure of chloroplast was destroyed by NaCl 600 mmol/L.