[Changes of hemodynamic parameters in normal pregnant women and their relationship with maternal basic characteristics].

Objective: To investigate the variation of reference ranges of hemodynamic parameters in normal pregnancy and their relation to maternal basic characteristics. Methods: A total of 598 healthy pregnant women who underwent regular prenatal examination at the Third Affiliated Hospital of Guangzhou Medical University from January to December 2023 were prospectively enrolled, and noninvasive hemodynamic monitors were used to detect changes in hemodynamic parameters of the pregnant women with the week of gestation, including cardiac output (CO), stroke volume (SV), thoracic fluid content (TFC), systemic vascular resistance (SVR), mean arterial pressure (MAP), and heart rate (HR). Relationships between hemodynamic parameters and maternal basic characteristics, including age, height, and weight, were analyzed using restricted cubic spline. Results: (1) CO (r=0.155, P<0.001), TFC (r=0.338, P<0.001), MAP (r=0.204, P<0.001), and HR (r=0.352, P<0.001) were positively correlated with the week of gestation, and SV was negatively correlated with the week of gestation (r=-0.158, P<0.001). There was no significant correlation between SVR and gestational age (r=-0.051, P=0.258). (2) CO exhibited a positive correlation with maternal height and weight (all P<0.001). The taller and heavier of pregnant women, the higher their CO. A linear relationship was observed between maternal weight and SV, MAP and HR (all P<0.01). As maternal weight increased, SV, MAP and HR showed an upward trend. Furthermore, there was an inverse association between maternal age and SVR (P<0.001). (3) There was a significant nonlinear association observed between TFC and body mass index during pregnancy (P<0.05). Additionally, a nonlinear relationship was found between SVR and MAP in relation to maternal age (all P<0.05). Notably, when the age exceeded 31 years old, there was an evident upward trend observed in both SVR and MAP. Conclusions: The hemodynamic parameters of normal pregnant women are influenced by their height, body weight, and age. It is advisable to maintain a reasonable weight during pregnancy and give birth at an appropriate age.

Long-term efficacy and safety of baricitinib in patients with severe alopecia areata: 104-week results from BRAVE-AA1 and BRAVE-AA2.

BACKGROUND: Efficacy of the Janus kinase (JAK) inhibitor baricitinib for severe alopecia areata (AA) continuously increased over 52 weeks in two Phase 3 trials. There are limited long-term data on JAK inhibitors in AA. OBJECTIVES: To evaluate efficacy and safety of baricitinib for severe AA through 104 weeks of continuous therapy. METHODS: Integrated data from the BRAVE-AA1 and BRAVE-AA2 Phase 3 trials included adults with Severity of Alopecia Tool (SALT) scores ≥50 (≥50% scalp hair loss) randomized to and continuously treated with 2-mg or 4-mg baricitinib through Week 104. Patients who qualified to remain on continuous treatment included subjects who achieved SALT score ≤20 at Week 52 (Week-52 responders; 2-mg: N = 65; 4-mg: N = 129) and baricitinib 4-mg-treated patients who had SALT score >20 at Week 52 but achieved SALT score ≤20 at prior visit(s) and/or had significant improvement in eyebrow or eyelash hair growth relative to baseline by Week 52 (Week-52 mixed responders; N = 110). Week-104 outcomes included the proportion of patients achieving SALT score ≤20 (≤20% scalp hair loss). Data were censored after treatment discontinuation. RESULTS: Among baricitinib 4-mg-treated and baricitinib 2-mg-treated Week-52 responders, 90.7% and 89.2%, respectively, maintained SALT score ≤20 at Week 104. Among Week-52 mixed responders, 39.1% reached SALT score ≤20 by Week 104. Continued improvement in eyebrow and eyelash regrowth was observed across groups. The most frequent treatment-emergent adverse events were COVID-19, upper respiratory tract infection, headache, nasopharyngitis, acne, urinary tract infection and creatine phosphokinase increase. CONCLUSIONS: Baricitinib demonstrated a high level of maintenance of efficacy over 104 weeks in patients with severe AA. Efficacy increased in Week-52 mixed responders, illustrating that long-term treatment is necessary to observe maximum benefit in some patients. No new safety signals were observed.

[Transmission characteristics and risk factors of household COVID-19 clusters caused by 2019-nCoV Omicron variant in Tianjin].

Objective: To understand the transmission characteristics and risk factors of household COVID-19 clusters caused by 2019-nCoV Omicron variant in Tianjin and provide evidence for COVID-19 prevention and control. Methods: Field epidemiological method was used to investigate the epidemiological characteristics of COVID-19 cases, and descriptive analysis was used to describe the epidemiological information. Results: A total of 430 cases were reported in this epidemic in Tianjin, in which 409 cases were included in this study. Among these cases, 70.90% (290/409) occurred in families. The family secondary attack rate was 33.64% The family secondary attack rate in age group 12-17 years (13.79%) was significantly lower than that in age group 18-49 years (36.48%), the OR was 0.378 (95%CI: 0.170-0.840). The logistic regression analysis showed that compared with centralized quarantine, the OR of the index cases found in closed-off/controlled areas and in home quarantine were 2.951 (95%CI:1.322-6.586) and 2.287 (95%CI:1.164-4.495), respectively, compared with the cases without sore throat, the OR of the index cases with sore throat was 3.003 (95%CI: 1.576-5.720), and compared with cases in families without completed COVID-19 vaccinations in all members, the OR of the cases in families with completed COVID-19 vaccinations in all members was 0.268 (95%CI: 0.132-0.552). Conclusions: The risk of household transmission of infection with Omicron variant was high. Detecting the index case in closed-off/controlled areas or in home quarantine and sore throat in index cases were the risk factors of the household transmission, completed COVID-19 vaccination was the protective factor.

[Clinical features and treatment efficacy of infantile renal tumors: a multicenter retrospective study].

Objective: To further understand the clinical features, treatment efficacy and risk factors for poor prognosis in infantile-onset renal tumors. Methods: Clinical data of 45 cases of infantile-onset renal tumors from June 2011 to November 2019 in Peking University First Hospital, Beijing Children's Hospital, Beijing Tongren Hospital and Beijing Shijitan Hospital were analyzed retrospectively. The clinical features were summarized and the prognoses were evaluated. Multi-disciplinary diagnosis and treatment was used, including surgery, chemotherapy and radiotherapy. Kaplan-Meier analysis was used to calculate the overall survival rate and the event-free survival rate, while the chi-square test was used to analyze the risk factors for poor prognosis. Results: Among 45 patients, 24 were males and 21 females. The age of onset was 7 (ranged 3-11) months, and the length of tumor at initial diagnosis was 9.7 (ranged 4.9-25.0)cm. The International Society of Pediatric Oncology (SIOP) staging: 5 cases (11%) were in stage Ⅰ, 22 cases in stage Ⅱ (49%), 8 cases in stage Ⅲ (18%), 6 cases in stage Ⅳ (13%), and 4 cases in stage Ⅴ (9%). Risk groups included 5 cases (11%) in the low-risk group, 22 cases (49%) in the intermediate-risk group, and 18 cases (40%) in the high-risk group. Forty-four cases (98%) did not receive preoperative biopsy, 26 cases (58%) received preoperative chemotherapy, 39 cases (87%) received postoperative chemotherapy, and 2 cases (4%) received three-dimensional conformal radiotherapy. The 5-year overall survival rate was (83±7)%, and the 5-year event-free survival rate was (76±8)%. Hematuria as the first symptom (3/8 vs. 83% (30/36), χ²=7.005, P=0.024), tumor long diameter≤8 cm (5/11 vs. 85% (28/33), χ²=5.606, P=0.027) and high-risk pathological group (7/18 vs.100% (26/26), χ²=21.928, P<0.01) were risk factors for poor prognosis of children with renal tumors in this group. Conclusion: The prognosis of children with infantile-onset renal tumors is fairly well, nevertheless the prognosis is poor in patients with hematuria as the first symptom and in high-risk pathological group.

Carcinogenesis of Male Oral Submucous Fibrosis Alters Salivary Microbiomes.

Most oral squamous cell carcinoma (OSCC) tumors arise from oral premalignant lesions. Oral submucous fibrosis (OSF), usually occurring in male chewers of betel quid, is a premalignant stromal disease characterized by a high malignant transformation rate and high prevalence. Although a relationship between the inhabited microbiome and carcinogenesis has been proposed, no detailed information regarding the oral microbiome of patients with OSF exists; the changes of the salivary microbiome during cancer formation remain unclear. This study compared the salivary microbiomes of male patients with OSCC and a predisposing OSF background (OSCC-OSF group) and those with OSF only (OSF group). The results of high-throughput sequencing of the bacterial 16S rRNA gene indicated that OSF-related carcinogenesis and smoking status significantly contributed to phylogenetic composition variations in the salivary microbiome, leading to considerable reductions in species richness and phylogenetic diversity. The microbiome profile of OSF-related malignancy was associated with increased microbial stochastic fluctuation, which dominated the salivary microbiome assembly and caused species co-occurrence network collapse. Artificial intelligence selection algorithms consistently identified 5 key species in the OSCC-OSF group: Porphyromonas catoniae, Prevotella multisaccharivorax, Prevotella sp. HMT-300, Mitsuokella sp. HMT-131, and Treponema sp. HMT-927. Robust accuracy in predicting oral carcinogenesis was obtained with our exploratory and validation data sets. In functional analysis, the microbiome of the OSCC-OSF group had greater potential for S-adenosyl-l-methionine and norspermidine synthesis but lower potential for l-ornithine and pyrimidine deoxyribonucleotide synthesis and formaldehyde metabolism. These findings indicated that the salivary microbiome plays important roles in modulating microbial metabolites during oral carcinogenesis. In conclusion, our results provided new insights into salivary microbiome alterations during the malignant transformation of OSF.

[Seroepidemiological survey and influencing factors of hepatitis E virus infection among key occupational population in Tianjin].

Objective: To evaluate the infection rate and influencing factors of hepatitis E virus (HEV) among key occupational population in Tianjin, so as to help occupational population to carry out HEV prevention and control. Methods: A combination of stratified random sampling and convenience sampling was carried out for the study in Tianjin in June 2019. The livestock and poultry-related farming workers, slaughtering workers, selling workers, doctors, farmers, seafood sellers, sewage pipeline workers as the key occupational population groups (1036 person) , and non key occupational population as the control group (200 person) , cross-sectional surveys were conducted in the groups. Enzyme-linked immunosorbent assay (ELISA) was used to detect the serum IgG and IgM antibodies to HEV, and logistic regression model was used to analyze the influencing factors of HEV infection. Results: The positive rate of anti-HEV IgG in key occupational group was 26.45% (274/1036) , which was higher than that in control group of 14.50% (29/200) (χ(2)=13.41, P<0.01) . The occupations with the highest positive rate of anti-HEV IgG were livestock (swine) , breeding and slaughtering workers, all of which reached 33.96% (18/53) . The difference in infection rates between different occupations was statistically significant (χ(2)=22.57, P<0.01) . Multivariate logistic regression analysis showed that the longer working years, high frequency of eating out (3-5, ≥6 times/week) , drinking raw water, eating under-cooked pork or pig liver, and low frequency of washing hands were risk factors for HEV infection in occupational population (P<0.05) . But the high education is a protective factor for HEV infection (P<0.05) . Conclusion: There is a high positive rate of anti-HEV IgG in key occupational population in Tianjin. It is necessary to strengthen the monitoring, publicity and education of the high-risk population, pay attention to personal and dietary hygiene.

[Investigation and analysis on characteristics of a cluster of COVID-19 associated with exposure in a department store in Tianjin].

Objective: To describe the epidemiological characteristics of a cluster of COVID-19 cases reported in Baodi district of Tianjin as of 18 February, 2020, which might be associated with the exposure in a local department store, and provide suggestions for prevention and control strategy development. Methods: The basic characteristics, time and area distributions, clinical manifestations, epidemiological history and transmission mode of the COVID-19 cases associated with the department store exposure were analyzed. Results: A total of 40 COVID-19 cases were associated with the department store exposure, accounting for 75.47% of the total confirmed cases (53 cases) reported in Baodi district. The cases were mainly at the age of 60 years or older (35.00%) and farmers (40.00%). The main clinical manifestations included fever (95.00%), cough (35.00%), and diarrhea (15.00%). The proportion of confirmed severe cases was 32.50%. The incidence curve showed that the incidence peak occurred on 31 January, 2020. Among the 40 cases, 6(15.00%) were department store employees, 19 (47.50%) were customers and 15 (37.50%) were close contacts (secondary cases). The first case occurred on 21 January, 2020, this case was a department store employee who had a purchasing history at whole sale markets in other provinces and cities before the onset, and 3 employees were still on duty after symptom onsets. The median of the incubation period of customer cases was 6 days, and the median of the interval between onset and medical treatment of customer cases was 7 days. Conclusion: This was a cluster epidemic of COVID-19, which might be associated with the exposure in the department store. By now, the current prevention and control measures have achieved satisfied effects.

Femtosecond laser-induced size reduction and emission quantum yield enhancement of colloidal silicon nanocrystals: effect of laser ablation time.

Colloidal silicon (Si) nanocrystals (NCs) with different sizes were successfully prepared by femtosecond laser ablation under different laser ablation time (LAT). The mean size decreases from 4.23 to 1.42 nm by increasing the LAT from 30 to 120 min. In combination with structural characterization, temperature-dependent photoluminescence (PL), time-resolved PL and PL excitation spectra, we attribute room-temperature blue emissions peaked at 405 and 430 nm to the radiative recombination of electron-hole pairs via the oxygen-deficient centers related to Si-C-H2 and Si-O-Si bonds of colloidal Si NCs prepared in 1-octene, respectively. In particular, the measured PL quantum yield of colloidal Si NCs has been enhanced significantly from 23.6% to 55.8% by prolonging the LAT from 30 to 120 min.

Genotype and allele frequencies of TYMS rs2790 A > G polymorphism in a Chinese paediatric population with acute lymphoblastic leukaemia.

WHAT IS KNOWN AND OBJECTIVE: Thymidylate synthase (TYMS) is an important target for methotrexate (MTX). Genetic variations in the TYMS gene contribute to the differences in treatment responses to MTX. The aim of this study was to investigate the distribution of a microRNA (miRNA) binding site polymorphism (rs2790 A > G) in the 3'-untranslated region (3'-UTR) of TYMS and its association with MTX concentration and haematological toxicity in Chinese paediatric patients with acute lymphoblastic leukaemia (ALL). METHODS: The Sequenom MassARRAY system was used for TYMS rs2790 A > G genotyping in 118 children with ALL. Serum MTX concentrations were measured by a fluorescence polarization immunoassay. Clinical data were extracted from the electronic medical records. RESULTS AND DISCUSSION: The minor allele frequency noted in this study (39.8%) was significantly higher than those in the CEU (Utah residents with northern and western Europe ancestry; 16.2%) and YRI (Yoruba in Ibadan, Nigeria; 25.0%) samples reported in the 1000 Genomes Project (P < .01). The frequency of MTX level >40 µmol/L at 24 hours in patients with the AA genotype (36.6%) was significantly higher than that in GG genotype carriers (5.9%, P < .05). However, the incidence rates of haematological toxicity were similar in the three genotype groups. Whereas there was evidence of higher blood levels in the A homozygotes, the evidence for this translating to higher toxicity was lacking. A larger study would be required to answer this. WHAT IS NEW AND CONCLUSION: The results of this study confirmed the significant ethnic differences in the distributions of the TYMS rs2790 A > G polymorphism. Whereas there was evidence of differences in MTX blood levels according to genotype, our study was not powered to show whether this would lead to more haematological toxicity.

Correlation between luminescence and structural evolution of colloidal silicon nanocrystals synthesized under different laser fluences.

We present a detailed investigation of the structural evolution and photoluminescence (PL) properties of colloidal silicon (Si) nanocrystals (NCs) synthesized through femtosecond laser ablation at different laser fluences. It is shown that the mean size of colloidal Si NCs increases from ∼0.97-2.37 nm when increasing laser fluence from 1.0-2.5 mJ cm-2. On the basis of structural characterization, temperature-dependent PL, time-resolved PL, and PL excitation spectra, we identify that the size-dependent spectral shift of violet emission is attributed to the quantum confinement effect. The localized excitons' radiative recombination via the oxygen-related surface states on the surface of the colloidal Si NCs is employed to explain the origin of the blue emission.

A novel slug-containing negative-feedback loop regulates SCF/c-Kit-mediated hematopoietic stem cell self-renewal.

The stem cell factor (SCF)/c-Kit pathway has crucial roles in controlling hematopoietic stem cell (HSC) renewal. However, little is known about the intracellular regulation of the SCF/c-Kit pathway in HSCs. We report here that Slug, a zinc-finger transcription repressor, functions as a direct transcriptional repressor of c-Kit in HSCs. Conversely, SCF/c-Kit signaling positively regulates Slug through downstream c-Myc and FoxM1 transcription factors. Intriguingly, c-Kit expression is induced by SCF/c-Kit signaling in Slug-deficient HSCs. The balance between Slug and c-Kit is critical for maintaining HSC repopulating potential in vivo. Together, our studies demonstrate that Slug functions in a novel negative-feedback regulatory loop in the SCF/c-Kit signaling pathway in HSCs.

[Prevalence of hepatitis C in Tianjin, China and related risk factors].

Objective: To investigate the prevalence of hepatitis C in Tianjin, China and major risk factors, and to provide a theoretical basis for the development of scientific prevention and control strategies for hepatitis C. Methods: The monitoring system of notifiable infectious diseases was used to establish the database of hepatitis C cases reported from 2004 to 2014 in Tianjin. With reference to the results of serological surveillance and special case-control investigation, a statistical analysis was performed to investigate the epidemiological characteristics and prevalence of hepatitis C in Tianjin, as well as related risk factors. Results: The report rate of hepatitis C in Tianjin showed a decreasing trend from 2004 to 2014(χ 2 = 150.018, P < 0.01). The group aged 60 years had the highest report rate(9.09/100000), and there were significant differences between this group and other groups(χ 2 = 2540.887, P < 0.01). The six urban districts in Tianjin had the highest report rate(6.54/100000), and there were significant differences between this area and other areas. The multivariate logistic regression analysis showed that a history of surgery(χ 2 = 12.57, P < 0.01), blood transfusion and blood products(χ 2 = 36.67, P < 0.01), hemodialysis(χ 2 = 4.62, P < 0.01), and intravenous drug use(χ 2 = 12.92, P < 0.01)were major risk factors for hepatitis C. Conclusion: The epidemic situation of hepatitis C in Tianjin tends to decrease in recent years. Although there is no effective vaccine for hepatitis C, it still can be prevented and treated. The most effective interventions for hepatitis C include strengthening health education and raising the awareness rate of hepatitis C in the whole population, as well as early detection, diagnosis, and treatment.

[Investigation of renal corticomedullary differentiation with age-related change on non-contrast-enhanced MRI].

OBJECTIVE: To evaluate the relationship between renal corticomedullary differentiation, renal cortical thickness and age-related changes with non-contrast-enhanced steady-state free precession(SSFP) magnetic resonance imaging (MRI) and spatially selective inversion recovery(IR) pulse technology as well as its applied value . METHODS: A total of 76 healthy volunteers had been recruited from August 2014 to June 2015 in First Hospital of China Medical University.All volunteers were divided into three groups: 2-40 years old, 41-60 years old, 61-80 years old. All 76 volunteers underwent non-contrast-enhanced steady-state free precession(SSFP) 3.0 T MRI scan using variable inversion times (TIs)(TI=1 000, 1 100, 1 200, 1 300, 1 400, 1 500, 1 600, 1 700 ms). The renal corticomedullary differentiation was observed and the signal intensity of renal cortex and medulla were measured respectively as well in order to calculate renal corticomedullary contrast ratio. Besides, renal cortical thickness and renal size were measured. RESULTS: All 76 volunteers were successfully performed all the sequences of MRI scan, including 152 useful imaging of kidney in total. The renal corticomedullary differentiation was clearly shown in all subjects. There was negative correlation between the optimal inversion time(TI) and age(r=-0.65, P<0.01). Similarly, negative correlation was observed between renal corticomedullary contrast ratio and age(r=-0.35, P<0.01). The mean renal cortical thickness of all subjects was (5.33±0.71)mm and there were statistically significant difference among those different groups, which was negative-related with age(r=-0.79, P<0.01). There was no statistically significant difference between sexuality and renal cortical thickness.Additionally, renal cortical thickness had no statistically significant difference in both sides of kidneys. CONCLUSION: The renal corticomedullary differentiation is depicted clearly by means of non-contrast-enhanced steady-state free precession MRI with spatially selective inversion recovery pulse technology. The optimal inversion time decreases along with the increase of age. In the meanwhile, the renal cortical thickness could be measured truthfully and accurately.

Origin of blue photoluminescence from colloidal silicon nanocrystals fabricated by femtosecond laser ablation in solution.

We present a detailed investigation into the origin of blue emission from colloidal silicon (Si) nanocrystals (NCs) fabricated by femtosecond laser ablation of Si powder in 1-hexene. High resolution transmission electron microscopy and Raman spectroscopy observations confirm that Si NCs with average size 2.7 nm are produced and well dispersed in 1-hexene. Fourier transform infrared spectrum and x-ray photoelectron spectra have been employed to reveal the passivation of Si NCs surfaces with organic molecules. On the basis of the structural characterization, UV-visible absorption, temperature-dependent photoluminescence (PL), time-resolved PL, and PL excitation spectra investigations, we deduce that room-temperature blue luminescence from colloidal Si NCs originates from the following two processes: (i) under illumination, excitons first form within colloidal Si NCs by direct transition at the X or Γ (Γ25 → Γ'2) point; (ii) and then some trapped excitons migrate to the surfaces of colloidal Si NCs and further recombine via the surface states associated with the Si-C or Si-C-H2 bonds.

Comparative adsorption of Eu(III) and Am(III) on TPD.

Comparative adsorption behaviors of Eu(III) and Am(III) on thorium phosphate diphosphate (TPD), i.e., Th4(PO4)4P2O7, have been studied using a batch approach and surface complexation model (SCM) in this study. The results showed that Eu(III) and Am(III) adsorption increased to a large extent with the increase in TPD dose. Strong pH-dependence was observed in both Eu(III) and Am(III) adsorption processes, suggesting that inner-sphere complexes (ISCs) were possibly responsible for the adsorption of Eu(III) and Am(III). Meanwhile, the adsorption of Eu(III) and Am(III) decreased to a different extent with the increase in ion strength, which was possibly related to outer-sphere complexes and/or ion exchange. In the presence of fulvic acid (FA), the adsorption of Eu(III) and Am(III) showed high enhancement mainly due to the ternary surface complexes of TPD-FA-Eu(3+) and TPD-FA-Am(3+). The SCM showed that one ion exchange (≡S3Am/Eu) and two ISCs (≡(XO)2Am/EuNO3 and ≡(YO)2Am/EuNO3) seemed more reasonable to quantitatively describe the adsorption edges of both Eu(III) and Am(III). Our findings obviously showed that Eu(III) could be a good analogue to study actinide behaviors in practical terms. However, it should be kept in mind that there are still obvious differences between the characteristics of Eu(III) and Am(III) in some special cases, for instance, the complex ability with organic matter and adsorption affinity to a solid surface.

The adsorption behavior of U(VI) on granite.

The effects of pH, counter ions and temperature on the adsorption of U(VI) on Beishan granite (BsG) were investigated in the presence and absence of fulvic acid (FA) and humic acid (HA). The adsorption edge of U(VI) on BsG suggested that U(VI) adsorption was mainly controlled by ion exchange and outer-sphere complexation at low pH, whereas inner-sphere complex was the dominant adsorption species in the pH range of 4.0-9.0. Above pH 9.0, Na2U2O7 might play an important role in the rise of U(VI) adsorption again. Counter ions such as Cl(-), SO4(2-) and PO4(3-) can provoke U(VI) adsorption on BsG to some extent, which was directly correlated to the complexing ability of U(VI)-ligand. More noticeably, the large enhancement of U(VI) adsorption in the presence of phosphate can be attributed to the ternary complex formation (BsG-PO4-UO2), precipitation ((UO2)3(PO4)2(s)) and secondary phase (Na-autunite). Both FA and HA can slightly increase U(VI) adsorption at low pH, whereas they strongly inhibited U(VI) adsorption at high pH range. Artificial synthesized granite (AsG) prepared in the laboratory is impossible to use as an analogue of natural granite because of the large difference in the adsorption and surface properties.

Investigation of Cs(I) uptake on Beishan soil combined batch and EDS techniques.

The uptake of Cs(I) on Beishan soil (BS) was strongly dependent on ionic strength and hardly dependent on pH over the observed pH range (6-13). The foreign cations competed with Cs(I) in the following order: K(+)>Mg(2+)>Ca(2+)≈Na(+)>Li(+). The uptake of Cs(I) was a pseudo-second-order process and the activation energy, E(a), was about 2.16kJ/mol. EDS analysis suggested that the most of Cs(I) was converged on the basal plane, and a small fraction bound on the frayed sorption site. All the results suggested that ion exchange was the main approach for Cs(I) uptake on BS.

The characteristics of placental transfer and tissue concentrations of nickel in late gestational rats and fetuses.

The dynamics of nickel (Ni) uptake, transfer, retention and clearance in fetuses and late gestational rats were investigated by assessing its distributions in placenta, maternal and fetal organs and tissues during the 24 h period after a single dose of (63)Ni intraperitoneal injection on gestational day 20. Peak (63)Ni radioactivity was detected at 0.5 h in maternal blood, at 3 h in placenta, fetal membranes, fetal blood, fetal heart, maternal kidney, lung, stomach, liver and brain, at 9 h in fetal kidney, stomach, liver and brain, and lastly at 24 h in fetal lung and amniotic fluid. The maximal (63)Ni radioactivity among all samples was detected consistently in the fetal membranes and placenta. The (63)Ni radioactivity in fetal blood was higher than that in maternal blood from 3 to 24 h. The fetal liver, heart, stomach and brain exhibited higher (63)Ni radioactivity than the corresponding maternal organs from 6 to 24 h. However, maternal kidney consistently exhibited significantly higher (63)Ni radioactivity than the fetal kidney. The (63)Ni in fetal lung and amniotic fluid increased throughout the period of experimental observation. These observations corroborated previous finding that nickel is actively transferred across the blood-placenta-barrier into fetus, but hardly from fetus to mother. Moreover, these results suggest that the placenta has a high affinity for nickel and its barrier does not protect the fetus from nickel exposure. The fact that nickel concentrations are higher in most fetal organs and tissues than in corresponding maternal organs and tissues in late gestation indicates that, unlike the dam, fetuses lack effective means for getting rid of excessive nickel due to its confined environment and relatively weak kidney functions. The situation is exacerbated by mother-to-fetus unidirectional transfer. Consequently, the fetuses are particularly vulnerable to the damaging effects of nickel.

Effect of MWCNTs on Gastric Emptying in Mice.

After making model of gastric functional disorder (FD), part of model mice were injected intravenously (i.v.) with oxide multi-walled carbon nanotubes (oMWCNTs) to investigate effect of carbon nanotubes on gastric emptying. The results showed that NO content in stomach, compared with model group, was decreased significantly and close to normal level post-injection with oMWCNTs (500 and 800 µg/mouse). In contrast to FD or normal groups, the content of acetylcholine (Ach) in stomach was increased obviously in injection group with 500 or 800 µg/mouse of oMWCNTs. The kinetic curve of emptying was fitted to calculate gastric motility factor k; the results showed that the k of injection group was much higher than FD and normal. In other words, the gastric motility of FD mice was enhanced via injection with oMWCNTs. In certain dosage, oMWCNTs could improve gastric emptying and motility.