[Clinical analysis of adverse reactions in patients with multidrug-resistant and rifampicin-resistant pulmonary tuberculosis treated with delamanid-containing regimen].

Objective: To explore the characteristics of adverse drug reactions during the 24-week therapy with delamanid-containing regimen for patients with multidrug-resistant and rifampicin-resistant pulmonary tuberculosis (MDR/RR-PTB). Methods: The prospective multicenter study was conducted from June 2020 to June 2023. A total of 608 eligible patients with MDR/RR-PTB were enrolled in 26 tuberculosis medical institutions in China including 364 males and 79 females, aged 39.6(19.0-68.0) years. Patients were treated with chemotherapy regimens containing delamanid. Patients were closely supervised during treatment of medication, and all adverse reactions occurring during treatment were monitored and recorded. The clinical characteristics of adverse reactions were evaluated by descriptive analysis. Chi-square test and multivariate logistic regression were used to analyze the related factors of QTcF interval prolongation (QT corrected with Fridericia's formula). Results: Of the 608 patients enrolled in this study, 325 patients (53.5%) reported 710 adverse events within 24 weeks of treatment. The top 6 most common complications were hematological abnormalities (143 patients, 23.5%), QT prolongation (114 patients, 18.8%), liver toxicity (85 patients, 14.0%), gastrointestinal reaction (41 patients, 6.7%), peripheral neuropathy (25 patients, 4.1%) and mental disorders (21 patients, 3.5%). The prolongation of QT interval mostly occurred in the 12th week after the first dose of medication. Serious adverse reactions occurred in 21 patients (3.5%). There were 7 patients (1.2%) with mental disorders, including 2 patients (0.3%) with severe mental disorders. Conclusions: The safety of dalamanid-based regimen in the staged treatment of MDR/RR-PTB patients was generally good, and the incidence of adverse reactions was similar to that reported in foreign studies. This study found that the incidence of QT interval prolongation in Chinese patients was higher than that reported overseas, suggesting that the monitoring of electrocardiogram should be strengthened when using drugs containing delamanid that may cause QT interval prolongation.

[Novel frameshift mutations in SALL4 in two Chinese families with Okihiro syndrome].

In the present study, clinical manifestations of two Chinese Okihiro syndrome families were analyzed, and genetic detections were performed on the two probands by exome sequencing and verified by Sanger sequencing for family members to determine the biological pathogenesis. Prenatal diagnoses were provided for three high-risk fetuses. The affected members exhibited a wildly spectrum of phenotypes, including ultrasound abnormalities of skeletal system (radius deformity and abnormal posture), and cardiac system (persistent common arterial trunk and ventricular septal defect) in the prenatal period of family 1, the severe phenotypes (grossly shortened and deformed forearm, Duane's anomaly and hearing loss), and the mild ones (usually only thenar dysplasia, or short radius styloid process). Two SALL4 variants, c.844delC p.(Q282Kfs*8) and c.2210delG p.(G737Vfs*23), have been identified respectively in two probands, and c.2210delG of SALL4 gene was unreported previously. The two variants were verified in all affected individuals, not in normal family members. Genotyping results of three fetuses indicated that one fetus was normal, and the two fetuses with heterozygous variation were affected. The two variants of SALL4 gene, c.844delC p.(Q282Kfs*8) and c.2210delG p.(G737Vfs*23), were the molecular pathological cause of Okihiro syndrome in the present study and enriched the spectrum of SALL4 variants. Our study provides accurate prenatal genetic diagnosis for the two families to avoid the birth of affected children.

[Imaging study on determining the rationality of atlantoaxial fixation angle based on the ratio of line segments between anatomical markers on lateral X-ray films].

Objective: To propose a method to determine the unreasonableness of the fixed angle in posterior atlantoaxial fusion surgery based on the ratio of line segments between anatomical landmarks of the atlantoaxial joint. Methods: A cross-sectional study was conducted. According to the inclusion criteria, a screening was performed on the database of asymptomatic volunteers who had full-spine lateral X-ray films taken at the Second Affiliated Hospital of Wenzhou Medical University from May 2016 to May 2021. A total of 207 volunteers were included, comprising 98 males with an age of (40.68±13.87) years and 109 females with an age of (42.64±14.45) years. On the lateral X-ray film, a line (L) parallel to the posterior margin of the odontoid process was drawn at the posterior edge of the lower articular surface of the axis (a), intersecting the atlas at points b, c, and d. The line segments ab, bd, bc, and the C1-C2 angle were measured, and the ratios of bd/ab and bc/ab were calculated. The ability of bd/ab and bc/ab to predict the unreasonable fixed angle of the atlantoaxial joint (≥22°) was analyzed by receiver operating characteristic (ROC) curve analysis in both male and female. The areas under the ROC curves (AUC) were calculated, and the performance of the two prediction methods was compared using the Delong's test. The cutoff value for distinguishing the unreasonableness of the C1-C2 angle and the sensitivity and specificity were calculated. Results: The ROC curve analysis in the male group showed that the AUC of bc/ab for predicting the unreasonable C1-C2 angle was 0.791 (95%CI: 0.696-0.867, P<0.001), with a cutoff value of 0.449, sensitivity of 97.3%, and specificity of 70.0%. The performance was significantly better than that of bd/ab (cutoff value 1.100, AUC=0.532, 95%CI: 0.428-0.634, sensitivity 26.3%, specificity 83.3%, P<0.001). The ROC curve analysis in the female group showed that the AUC of bc/ab for predicting the unreasonable C1-C2 angle was 0.804 (95%CI: 0.745-0.852, P<0.001), with a cutoff value of 0.488, sensitivity of 90.5%, and specificity of 58.6%. The performance was significantly better than that of bd/ab (cutoff value 0.960, AUC=0.687, 95%CI: 0.624-0.748, sensitivity 90.5%, specificity 44.8%, P=0.041). Conclusions: The bc/ab value can be used as an effective indicator to predict the unreasonable C1-C2 angle in posterior atlantoaxial fusion surgery with high diagnostic accuracy. The cutoff value for males is<0.449, and for females is<0.488.

[Analysis of genetic variation in patients with Waardenburg syndrome type â ¡ by next generation sequencing].

Objective: To detect gene mutation sassociated with deafness in four Waardenburg syndrome (WS) type Ⅱ patients, and to explore the possible mechanism of molecular genetics. Methods: All patients with WS were identified at the genetic and prenatal diagnosis center of the First Affiliated Hospital of Zhengzhou University from August 2015 to December 2018.Clinical materials and peripheral blood were collected from patients and family members. The genes associated with deafness of the patients were tested by next generation sequencing(NGS). And suspected mutations were verified by Sanger sequencing. Results: All patients carried heterozygous mutations in SOX10, they were c.355_356insTCAGGCAGCGC, c.1106_1107insTGGGGCCCCCCACACTA, c.511T>C (p.Y171H), c.91_100del. According to the guidelines for genetic variation of the Amercian College of Medical Genetics and Genomics (ACMG), three frameshift mutations were pathogenic mutations, one missense mutation was likely pathogenic mutation. Conclusion: Application of next generation sequencing technologies make gene diagnosis of Waardenburg syndrome efficiently and accurately.

[Efficacy and safety of non-vitamin K antagonist versus vitamin K antagonist oral anticoagulants in the prevention and treatment of thrombotic disease in active cancer patients: a systematic review and meta-analysis of randomized controlled trials].

Object We aimed to compare the efficacy and safety of non-vitamin K antagonist oral anticoagulants (NOAC) and vitamin K antagonist (VKA) in the prevention and treatment of thrombotic diseases in patients with active cancer. Methods: To find randomized controlled trials (RCT) in which NOACs were compared VKAs in active cancer, we searched the electronic databases (PubMed, Web of Science and Clinical Trials) up to May 2019 and and languages restricted to Chinese and English. According to the screening strategy, two researchers independently screened and extracted literature, evaluated the quality of literature, the suitability of collected cross study data for analysis, and tested the heterogeneity. The relative risk (RR) and 95% confidence interval (95%CI) of major bleeding, clinically related non-major bleeding, VTE, stroke and all-cause mortality in active cancer patients with VTE, active cancer patients with non-valvular atrial fibrillation (NVAF) was calculated and the results were compared between NOAC with VKA. Results: A total of 9 RCTs were included, including 5 cancers with VTE (5/9) and 4 cancers with NVAF (4/9). A total of 5 867 patients were included. After excluding 1 818 (30.99%) patients with cancer history, 4 049 (68.86%) patients with active cancer were statistically analyzed. Among them, 2 278 (56.26%) received NOAC treatment, 1 771 patients (43.74%) received VKA treatment. The quality of the included documents was high (all scores were>5 points), and the data of each included document could be summarized and analyzed (P>0.05). The heterogeneity of main outcome events was very low (I2 = 0). In VTE patients with active cancer, NOACs were more effective in reducing recurrence of VTE （RR=0.55, 95%CI 0.36 -0.84; P = 0.005) and clinically related non-major bleeding (RR=0.77, 95%CI 0.60 -0.98; P = 0.03) than VKAs. In NVAF patients with active cancer, efficacy of NOACs and VKAs was similar in terms of reducing VTE, stroke, clinically related non-major bleeding, major bleeding and all-cause mortality events (P>0.05). Conclusions: For patients with active cancer accompanied by VTE, NOAC may has more advantages in efficacy and safety compared to VKA in the prevention and treatment of thrombotic diseases.

Growth and laser properties of Nd3+-doped Bi4Ge3O12 single-crystal fiber.

The Nd3+-doped Bi4Ge3O12 (BGO) single-crystal fiber (SCF) was successfully grown by the micro-pulling-down method with the resistance heating system. The fluorescence spectrum and transmission spectrum of the Nd:BGO SCF were measured. Excited by a continuous-wave 808-nm laser diode, a fluorescence peak around 1064 nm was observed. At an absorbed pump power of 15.25 W, the Nd:BGO SCF laser delivered a power of 3.37 W with a slope efficiency of 31.2%.

Double ventricular response in dual AV nodal pathways mimicking interpolated premature beat.

Double ventricular response in dual atrioventricular (AV) nodal pathways can result in nonreentrant supraventricular tachycardia. Since this condition was first described in 1979, around 20 cases have been reported. Here, we present the case of a patient with a confirmed diagnosis of double ventricular response in dual AV nodal pathways resembling an interpolated premature beat who underwent successful radiofrequency ablation of the slow pathway.

[Relationship between FGF23/FGFR4 expression in atrial tissue and atrial fibrosis in patients with atrial fibrillation].

Objective: To observe the expression of fibroblast growth factor 23 (FGF23) and FGFR4 in patients with atrial fibrillation (AF) and its relationship with atrial fibrosis. Methods: Fifty-one patients with rheumatic heart disease undergoing cardiac surgery at the Second Affiliated Hospital of Nanchang University from October 2016 to April 2017 were divided into two groups according to whether they were complicated with atrial fibrillation: 39 patients with persistent AF(AF group), and 12 patients with sinus rhythm (SR group). The right atrial appendage was cut out during cardiac surgery. The expression of FGF23 and FGFR4 mRNA was detected by quantitative real-time PCR. The expression of FGFR4 protein was detected by Western blot. Atrial structure was evaluated by echocardiography. Masson staining was used to evaluate the degree of atrial fibrosis. The expression of FGF23 and FGFR4 was compared between the two groups.Additionally, the relationship between FGF23 and FGFR4 expression and atrial fibrosis was evaluated. Results: AF group had significantly higher right and left atrial diameter than SR group((40.1±1.6 )mm vs (34.1±1.5)mm, (52.4±2.9)mm vs (41.3±2.4)mm, all P<0.05) . There were no statistically significant differences in age, gender, ejection fraction between the two groups. The expression of FGF23 and FGFR4 mRNA in AF group were significantly higher than those in SR group (1.93±0.32 vs 0.93±0.14, 1.89±0.17 vs 0.91±0.11, both P<0.05). Compared with the SR group, the protein expression of FGFR4 in the AF group was significantly higher(1.76±0.21 vs 0.84±0.12). In AF group, there was no correlation between FGF23 mRNA and atrial diameter (r=0.274 (left atrial), r=0.238 (right atrium), both P>0.05). Meanwhile, FGFR4 mRNA and protein expression had no correlation with atrial diameter either. There was positive correlation between FGF23 mRNA and atrial collagen volume fraction in AF group (r=0.42, P<0.05). The expression of FGFR4 mRNA and protein were positively correlated with the atrial collagen volume fraction (r=0.573, r=0.478, all P<0.05). Conclusion: The expression of FGF23 and FGFR4 in atrial fibrillation patients is increased, which is positively correlated with atrial fibrosis, suggesting that FGF23/FGFR4 pathway may play an important role in atrial fibrillation by promoting atrial fibrosis.

[Prevalence and influential factors of stroke in Jiangxi Province in 2014].

Objective: To discuss the prevalence and influential factors of stroke among population in Jiangxi Province. Methods: Four cities in urban areas and four counties in rural areas were selected firstly, in which two districts or townships were selected; and then three communities or villages were chosen from each district and township, respectively, using the simple random sampling (SRS) method. Finally 15 269 subjects aging 15 years old or above, living in Jiangxi Province ≥6 months were randomly selected to participate in this survey from November 2013 to August 2014. Information of population characteristics, life behavior way, individual disease history were collected through questionnaire survey, and height, weight, waist circumference, blood pressure, body fat rate, visceral fat index and so on were measured by instruments. Risk factors of stroke prevalence were analyzed by the unconditioned logistic regression analysis. Results: A total of 15 269 participants (6 267 males) from 15 364 eligible participants were included in the statistical analysis. Out of which, 7 793 participants came from urban areas, and their average age was (53.04±17.91) years old. In this study, 226 stroke patients (117 males) were found among15 269 participants, including 122 urban participants and 104 rural participants, whose average age was (67.76±9.74) years old. The prevalence of stroke was 1 480.12/100 000 in 2014, which was separately 1 866.92/100 000 and 1 210.84/100 000 among males and females. The prevalence of people aging (45-49) years old was 413.79/100 000 (6/1 450) , while which among people aging 75 years old and above was 3 311.62/100 000 (61/1 842) . The prevalence of stroke among residents in Jiangxi presented an uprising tendency with age increasing (linear-by-linear association χ(2)=62.23, P<0.01). The research showed that when other influencing factors including gender, BMI, waist circumference, pulse-pressure difference, VAI, and sleeping time in non-working days were controlled, hypertensive patients had a higher risk of stroke than people without hypertension (OR=6.88, 95%CI: 4.90-9.67), drinkers had a higher risk of stroke than non-drinkers (OR=1.56, 95%CI: 1.17-2.08), compared with people <65 years old, people aged 65-74 years old and ≥75 years old had a higher risk of stroke, the value of OR (95%CI) were 1.88 (1.36-2.59) and 1.97 (1.39-2.80), respectively, compared with people with normal body fat percentage, people whose body fat percentage on high side and people who with high body fat percentage had a higher risk of stroke, the value of OR (95%CI) were 1.71 (1.18-2.48) and 1.74 (1.18-2.56), respectively, people with sleep time >8 h had a higher risk of stroke than those with sleep time of 6-8 h. Conclusion: There was a high stroke prevalence among residents in Jiangxi province. Hypertension, drinking, age, BFP and sleep duration were associated with stroke prevalence. Corresponding measures for high-risk population and risk factors should be strengthened to prevent and control the stroke.

[PTPS gene analysis and prenatal diagnosis in patients with 6-pyruvoyl-tetra hydropterin synthase deficiency].

Objective: To analyze the variations of PTPS gene in patients with suspected 6-pyruvoyl-tetra hydropterin synthase deficiency (PTPSD) and to make prenatal diagnosis in high-risk families. Methods: Chemiluminescence was used for phenylalanine detection in blood or dried blood spots.Patients with phenylalanine concentration over 120 µmol/L were detected by urine pterin analysis, and the activity of dihydropteridine reductase (DHPR) was detected. tetrahydrobiopterin loading tests were performed in suspected patients with abnormal urinary pterin profiles. PTPS gene variation analysis was performed by direct Sanger sequencing based on PCR amplification. Prenatal diagnosis in 7 high-risk families was performed by chorionic villus sampling when the genotype was identified. Results: In 656 patients with hyperphenylalanine, 22 cases were diagnosed as PTPSD clinically. 16 variations were detected in the 22 PTPSD cases. The 5 variations, p.Lys77Arg, p.Ile84Phe, c.315-2A>G, c.244-2A>T, c.187-1G>T, were identified as novel variations. Two fetuses carried the same mutation with the proband and therefore were thought to be PTPSD fetuses. Three fetuses carried only one mutant allele and thus were thought to be PTPSD carriers. The other 2 fetuses carried no mutations and were presumed normal. Conclusions: PTPS gene variation analysis is necessary to confirm the diagnosis. Prenatal diagnosis could help avoiding the defect birth in PTPSD families.

[Genetic characterization of varicella zoster virus in Jilin province in 2014, China].

OBJECTIVE: To clarify the genotype of wild-type strains of varicella zoster virus (VZV) in Jilin province in 2014, and to discriminate between v-Oka vaccine strains and wild-type strains. METHODS: Vesicle fluid and throat swab samples were collected from 13 individuals with suspected VZV in Jilin province from January to December 2014. Viral DNA was extracted, the fragments of 15 open reading fragments (ORFs) were amplified by polymerase chain reaction (PCR), and viral genotypes were determined by single nucleotide polymorphisms (SNP). PCR restriction fragment length polymorphism (RFLP) was used to distinguish between wild-type strains and v-Oka vaccine strains. The results were analyzed with MEGA5 software, using the VZV reference strain sequences from GenBank. RESULTS: The 13 suspected samples included 5 males and 8 females, aged 11-27 years (mean: (16.69±5.48) years). Sampling was performed on days 0 to 3 of suspected infection. VZV strains were detected in 8 samples, all belonging to Clade 2. There was a synonymous mutation (T>C) in SNP18082 compared with the v-Oka vaccine strain. Analysis of PCR-RFLPs showed that all 8 positive samples were wild-type strains (PstⅠ(+)BglⅠ(+)SmaⅠ(-)). CONCLUSIONS: The study revealed that the VZV strains circulating in Jilin province in 2014 were wild-type strains belonging to Clade 2.

Prenatal diagnosis of Chinese families with phenylketonuria.

The aim of this study is to investigate the ability to prenatally diagnose phenylketonuria (PKU) by using phenylalanine hydroxylase (PAH) gene mutation analysis combined with short tandem repeat (STR) linkage analysis in 118 fetuses from 112 Chinese families. Genomic DNA was extracted from the peripheral blood from members of 112 families and the exons and exon-intron boundaries of the PAH gene were amplified by PCR. PCR products were analyzed by bi-directional Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA). The three variable number of tandem repeat (VNTR) markers PAH-1, PAH-26, PAH-32 were used in the prenatal diagnosis for the PKU families. We identified a spectrum of 63 different mutations, including 61 point mutations and indels, two large exon deletion mutations, and five novel mutations. A substantial proportion of mutant alleles were accounted for by p.R243Q (15.62%), EX6-96AG (9.82%), p.V399V (7.59%), p.Y356X (6.70%), and p.R413P (5.36%). The same mutations were identified in 31 prenatally genotyped fetuses. We identified 58 fetuses that carried only one mutant allele and 29 fetuses that carried no mutations of PAH and were presumed normal. PAH gene mutation analysis combined with STR linkage analysis can provide rapid and accurate prenatal diagnosis for PKU families.

Prenatal diagnosis based on HPRT1 gene mutation in a Lesch-Nyhan family.

We explored the feasibility of applying gene diagnosis in prenatal diagnosis by analysis of hypoxanthine-guanine phosphoribosyltransferase-1 (HPRT1) gene mutation in a Chinese Lesch-Nyhan family. A homozygous mutation of p.R170X (c.508C＞T) in HPRT1 gene was detected in the proband, and a heterozygous mutation of p.R170X was detected in his mother. This mutation failed to be found in the 50 unrelated healthy individuals. Prenatal diagnosis indicated that the foetus was male and also carried p.R170X (c.508C＞T) mutation, same as the proband. Parents of the foetus decided termination of pregnancy, and the result of gene analysis for the aborted tissue was consistent with that of prenatal diagnosis. We can see that Lesch-Nyhan syndrome (LNS) is caused by non-sense mutation p.R170X（c.508C＞T）in HPRT1 gene in this family. Prenatal gene diagnosis is a valid strategy to prevent LNS because it can avoid the birth of LNS foetuses.

Spin-filtering, giant magnetoresistance, rectifying and negative differential resistance effects in planar four-coordinate Fe complex with graphene nanoribbon electrodes.

By using the nonequilibrium Green's function formalism combined with the density functional theory, we have investigated the spin-polarized transport properties of a planar four-coordinate Fe complex sandwiched between two zigzag-edge graphene nanoribbon (ZGNR) electrodes, where the ZGNRs are modulated by external magnetic field. The results show that the system can exhibit perfect dual spin-filtering and spin-rectifying effects at a wide bias range, giant magnetoresistance effect with large magnetoresistance ratio at small bias, and obvious negative differential resistance behavior. The mechanisms are proposed for these phenomena.

Mutation analysis and prenatal diagnosis for three families affected by isolated methylmalonic aciduria.

Isolated methylmalonic acidemia (MMA) is a genetically heterogeneous disorder caused mainly by deficiency of methylmalonyl-CoA mutase. In the present study, we analyzed MUT gene mutations in 3 Chinese couples with a birth history of isolated MMA. We also provided prenatal diagnoses for the detected mutation. Exons and exon-intron boundaries of the MUT gene were analyzed by polymerase chain reaction and direct sequencing. Prenatal genetic diagnoses were performed by chorionic villus sampling after the genotypes of parents were determined. Six heterozygous mutations in the MUT gene were identified in the 3 families, including c.1880A>G (p.H627R) and IVS9-1G>A for family 1, c.1741C>T (p.R581X) and c.729insTT (p.D244fX39) for family 2, and c.616C>T (p.Q206X) and c.1280G>A (p.G427D) for family 3. Among these, c.616C>T (p.Q206X), c.1280G>A (p.G427D), IVS9-1G>A, and c.1741C>T (p.R581X) were novel mutations. These mutations were not detected in 100 normal controls. The fetus in pedigree 3 was free of the mutations carried by the parents, while the fetuses in pedigrees 1 and 2 were heterozygous mutation carriers. All 3 families decided to continue with their pregnancies and the neonates did not show any symptoms of MMA after birth. Our results indicated that mutations in the MUT gene are the primary cause of isolated MMA, and that most mutations were novel. For families with early-onset isolated MMA, direct sequencing of the MUT gene is crucial for genetic counseling, prenatal diagnosis, and identification of carriers.

[A survey on the current situation of serum vitamin A and vitamin D levels among children aged 2-<7 years of 20 cities in China].

Objective: To investigate serum vitamin A and vitamin D status in children aged 2-<7 years in 20 cities in China. Methods: A cross-sectional study was conducted. A total of 2 924 healthy children aged 2-<7 years were recruited from September 2018 to September 2019 from 20 cities in China, categorized by age groups of 2-<3 years, 3-<5 years, and 5-<7 years. The demographic and economic characteristics and health-related information of the enrolled children were investigated. Body weight and height were measured by professional staff members. The serum vitamin A and vitamin D levels were detected by high-performance liquid chromatography-tandem mass spectrometry. Chi-square test and Logistic regression were applied to analyze the association between vitamin A and vitamin D deficiency and insufficiency as well as their underlying impact factors. Results: The age of the 2 924 enrolled children was 4.33 (3.42, 5.17) years. There were 1 726 males (59.03%) and 1 198 females (40.97%). The prevalences of vitamin A and vitamin D deficiency in enrolled children were 2.19% (64/2 924) and 3.52% (103/2 924), respectively, and the insufficiency rates were 29.27% (856/2 924) and 22.20% (649/2 924), respectively. Children with both vitamin A and vitamin D deficiencies or insufficiencies were found in 10.50% (307/2 924) of cases. Both vitamin A (χ2=7.91 and 8.06, both P=0.005) and vitamin D (χ2=71.35 and 115.10, both P<0.001) insufficiency rates were higher in children aged 3-<5 and 5-<7 years than those in children aged 2-<3 years. Vitamin A and vitamin D supplementation in the last 3 months was a protective factor for vitamin A and D deficiency and insufficiency, respectively (OR=0.68 and 0.22, 95%CI 0.49-0.95 and 0.13-0.40, both P<0.05). The rates of vitamin A and D insufficiency was higher in children with annual household incomes <60 000 RMB than in those with annual household incomes ≥60 000 RMB (χ2=34.11 and 10.43, both P<0.01). Northwest and Southwest had the highest rates of vitamin A and vitamin D insufficiency in children aged 2-<7 yeas, respectively (χ2=93.22 and 202.54, both P<0.001). Conclusions: Among 20 cities in China, children aged 2-<7 years experience high rates of vitamin A and vitamin D insufficiency, which are affected by age, family economic level, vitamin A and vitamin D supplementation, and regional economic level. The current results suggest that high level of attention should be paid to vitamin A and vitamin D nutritional status of preschool children.

Inhibitory effects of tea extract on aflatoxin production by Aspergillus flavus.

UNLABELLED: Aflatoxins, one of the most carcinogenic substances, have been implicated as a potential threat to the safety of tea beverages. In this study, we studied the inhibitory effects of the aqueous extracts from several Chinese traditional teas, such as green tea, black tea, flower tea, raw Puer tea (naturally fermented Puer tea) and Puer tea (inoculated Puer tea), on the growth and aflatoxin production of Aspergillus flavus. All the tested extracts inhibited the production of aflatoxin B1, whereas they did not inhibit mycelial growth of A. flavus. Considering the highest inhibitory effect of Puer tea extract on aflatoxin production, a semi-quantitative RT-PCR was designed to detect its impacts on the expression of genes responsible for the regulation of aflatoxin synthesis. The results showed that the transcriptions of both aflS and aflR were down-regulated to undetectable levels by the addition of Puer tea extract. This study indicated that most tea contained molecules inhibitory to aflatoxin production, which were very important factors for the risk assessment of tea exposed to aflatoxin. Some tea extracts could be developed as antiaflatoxin agents in food preservation. SIGNIFICANCE AND IMPACT OF THE STUDY: Recently, safety concerns of the popular Puer tea have arisen because of aflatoxin contamination. In this study, we analysed the inhibitory effect of 30 tea aqueous extracts on the growth and aflatoxin production of Aspergillus flavus. Our results indicated that most tea inhibited aflatoxin production by down-regulating the transcription of aflR and aflS. The findings could contribute to the safety assessment of tea exposed to aflatoxin and provide some useful data concerning a new approach for controlling aflatoxin contamination.

Surface transfer doping of hydrogen-terminated diamond by C60F48: energy level scheme and doping efficiency.

Surface sensitive C1s core level photoelectron spectroscopy was used to examine the electronic properties of C(60)F(48) molecules on the C(100):H surface. An upward band bending of 0.74 eV in response to surface transfer doping by fluorofullerene molecules is measured. Two distinct molecular charge states of C(60)F(48) are identified and their relative concentration determined as a function of coverage. One corresponds to ionized molecules that participate in surface charge transfer and the other to neutral molecules that do not. The position of the lowest unoccupied molecular orbital of neutral C(60)F(48) which is the relevant acceptor level for transfer doping lies initially 0.6 eV below the valence band maximum and shifts upwards in the course of transfer doping by up to 0.43 eV due to a doping induced surface dipole. This upward shift in conjunction with the band bending determines the occupation of the acceptor level and limits the ultimately achievable hole concentration with C(60)F(48) as a surface acceptor to values close to 10(13) cm(-2) as reported in the literature.

[Effect of behavioral intervention based on social media to promote HIV/syphilis testing in young men who have sex with men].

Objective: To evaluate the effect of social media based behavioral intervention on promoting joint testing of HIV and syphilis in young men who have sex with men (MSM). Methods: After the recruitment, the participants who met the inclusion criteria were randomly divided (1∶1) into two groups, i.e. social media intervention group and control group. The control group was given routine voluntary counseling and testing (VCT) services. The intervention group was also given VCT services, besides; the comprehensive strategies through social media, including regular health education message and testing information sending, were given to them to strengthen the behavioral intervention. Follow up was conducted for the participants for 12 months after the intervention. The number and the proportion of young MSM receiving HIV and syphilis testing, and the reported proportion of the young MSM with sexually transmitted diseases (STD) symptoms between the intervention group and the control group were compared to evaluate the effect of the intervention. Results: A total of 315 young MSM were recruited (158 in the intervention group and 157 in the control group), in whom 248 young MSM completed the follow up. The follow-up rate was 78.7%. There was no significant difference in baseline characteristics between the intervention group and the control group (all P>0.05). The proportion of young MSM receiving more than one joint testing in the intervention group was slightly higher than that in the control group (53.2% vs. 48.4%, rate difference (RD): 4.8%, 95%CI: -7.5%-17.0%, P=0.448) without significant difference. However, in the young MSM who used condoms in the last anal sex, the proportion of those receiving more than one joint testing in the intervention group was higher than that in the control group (63.8% vs. 46.1%, RD: 17.7%, 95%CI: 1.5%-32.6%, P=0.035). In addition, the reported proportion of young MSM with STD symptoms in the intervention group was significantly lower than that in the control group (6.3% vs. 18.0%,RD: -11.7%, 95%CI: -20.6%- -3.0%, P=0.005). Conclusion: Compared with routine VCT, social media based behavioral intervention might promote joint HIV and syphilis testing in the young MSM who used condom in the study. It could significantly reduce the reporting proportion of STD symptoms, suggesting that this method can promote the AIDS and STD prevention related behaviors in young MSM.