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1.
ABSTRACT. The growing fetus and infant are at risk of becoming deficient of zinc, an adequate supply of which is essential for normal growth and development. Mild maternal zinc depletion was strongly associated with intrauterine growth retardation. Low levels of zinc in maternal plasma and poor placental perfusion reduced the materno-fetal transfer of zinc. Mean maternal dietary intake of zinc was 60% recommended daily allowance and mothers of small-for-gestational-age (SGA) babies consumed significantly less zinc than mothers of appropriate-for-gestational-age babies. In addition, iron/folate supplements, which are often routinely prescribed during pregnancy, despite dietary intakes of iron and folate being adequate, significantly decreased the oral bio-availability of zinc in pregnant women. Zinc supplementation may be beneficial to women at risk of delivering SGA babies. Zinc requirements and interactions are also important to consider when designing mineral supplements for preterm babies, infant formulae and food fortification in developing countries.  相似文献   

2.
The relation between maternal and cord blood folate activity was investigated in a group of 110 primigravidae and their infants. Approximately half of these mothers had received folic acid supplements during their pregnancy, and the effects of this on infant blood folate levels at birth and at 6 weeks were also studied.In unsupplemented pregnancies there was a significant relation between infant and maternal blood folate levels at delivery.The results of folic acid supplementation during pregnancy were reflected by higher cord blood values, but 6 weeks after delivery infant plasma folate levels were essentially the same in both groups and independent of maternal supplies before delivery.  相似文献   

3.
Conotruncal cardiac defects are partially prevented by maternal folic acid supplementation. However, the biochemical mechanism is unknown. Maternal autoantibodies to folate receptors, previously associated with increased risk for neural tube defects, also may account for this effect. This study aimed to examine the titers of folate receptor-blocking autoantibodies in mothers of children with conotruncal congenital heart defects and to compare them with those in the general population. Serum samples were obtained from 22 women whose pregnancies were complicated by conotruncal congenital heart malformations. Groups of samples were analyzed for autoantibodies against [3H] folic acid-labeled folate receptors, quantitative amounts of immunoglobulin G (IgG) and IgM autoantibodies to the folate receptor, and for ability to block-bind folic acid to receptors. No elevated levels of antibodies binding to [3H] folic acid-labeled folate receptors were found. No difference was found in antifolate receptor alpha-IgG or IgM median levels between cases (261 vs. 240 μg/mL) and control subjects (773 vs. 924 μg/mL). There was no increased blocking of folic acid binding between cases [0.69 ng/mL; 95 % confidence interval (CI), 0.006–0.01] and control subjects (0.69 ng/mL; 95 % CI, 0.003–0.013). Although epidemiologic evidence suggests that periconceptual folic acid may prevent many conotruncal congenital heart defects, the current study suggests that this effect is unlikely to be explained by the presence of maternal autoantibodies to folate receptor. These data suggest that a strategy of screening women for such autoantibodies will not identify a high-risk group of women to target for supplemental folic acid to prevent congenital heart defects.  相似文献   

4.
Our earlier studies both in animals and in humans have indicated that micronutrients (folic acid, vitamin B12) and long‐chain polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), are interlinked in the one‐carbon cycle, which plays an important role in fetal ‘programming’ of adult diseases. The present study examines the levels of maternal and cord plasma fatty acids, maternal folate, vitamin B12 and homocysteine in healthy mothers at various time points during pregnancy and also examine an association between them. A longitudinal study of 106 normal pregnant women was carried out, and maternal blood was collected at three time points, viz., T1 = 16–20th week, T2 = 26–30th week and T3 = at delivery. Cord blood was collected at delivery. Fatty acids were estimated using a gas chromatograph. Levels of folate, vitamin B12 and homocysteine were estimated by the chemiluminescent microparticle immunoassay (CMIA) technology. Maternal plasma folate (P < 0.05), vitamin B12 (P < 0.01) and DHA (P < 0.05) levels were lowest, while maternal homocysteine levels were highest (P < 0.01) at T3. There was a negative association between maternal DHA and homocysteine at T2 (P < 0.05) and T3 (P < 0.01). There was a positive association between plasma DHA in maternal blood at T3 and cord blood. Furthermore, there was a positive association between maternal folate and vitamin B12 at T3 and baby weight, whereas maternal homocysteine at T1 were inversely associated with baby weight at delivery. Our study provides evidence for the associations of folic acid, vitamin B12, homocysteine with DHA and baby weight, suggesting that a balanced dietary supplementation of folate–vitamin B12–DHA during pregnancy may be beneficial.  相似文献   

5.
The prevalence of neural tube defect (NTD)‐affected pregnancies ranges between 0.4 and 2/1000 pregnancies in EU. NTDs result in severe malformations and sometimes miscarriages. Children born with NTD suffer for the rest of their life of disability and chronic healthcare issues, and many women therefore choose termination of pregnancy if NTD is diagnosed prenatally. Women planning for pregnancy are recommended to eat 400 μg folic acid/d, whereas average figures across Europe indicate intakes of ~250 μg/d for women of fertile age, a gap that could be bridged by implementation of folic acid fortification. The results of mandatory folic acid fortifications introduced in USA and Canada are a decrease between 25 and 45% of NTD pregnancies. Conclusion: Evidence‐based NTD prophylaxis is now practised in more than 60 countries worldwide. EU countries worry over possible cancer risks, but ignore a wealth of studies reporting decreasing cancer risks with folate intakes at recommended levels. Currently, there are indications of a U‐shaped relationship, that is, higher cancer risks at low folate intakes (<150 μg/day) and highly elevated folate intakes (>1 mg/day), respectively. However neither the global World Cancer Research review nor EU’s European Food Safety Authority report present data on increased cancer risk at physiological folate intake levels. Therefore, EU should act to implement folic acid fortification as NTD prophylaxis as soon as possible.  相似文献   

6.
Periconceptional folic acid significantly reduces the risk of neural tube defects. It is difficult to achieve optimal levels of folate by diet alone, even with fortification of flour, especially because flour consumption in Canada is slightly decreasing. Intermittent concerns have been raised concerning possible deleterious effects of folate supplementation, including the masking of symptoms of vitamin B12 deficiency and an association with cancer, especially colorectal cancer. Both concerns have been disproved. The Canadian Paediatric Society endorses the following steps to enhance folate intake in women of child-bearing age: encouraging the consumption of folate-rich foods such as leafy vegetables, increasing the level of folate food fortification, taking a supplement containing folate and B12, and providing free folate supplementation to disadvantaged women of child-bearing age. These recommendations are consistent with those of the Society of Obstetricians and Gynaecologists of Canada.  相似文献   

7.
Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy. Modern treatment protocols allow achievement of long-term event-free survival rates in up to 85% of cases, although the treatment response varies among different patient groups. It is hypothesized that treatment response is influenced by the IL15 gene variations, although research results are conflicting. To analyze IL15 gene variations influence treatment response, clinical course and the risk of developing ALL we performed a case–control and family-based study. The study included 81 patients with childhood ALL. DNA samples of both or one biological parent were available for 62 of ALL patients and 130 age and gender adjusted healthy samples were used as a control group. Analyzed IL15 gene variations: rs10519612, rs10519613 and rs17007695 were genotyped using PCR-RFLP assay. Our results shows that IL15 gene variations haplotypes are associated with the risk of developing childhood ALL (p < 0.05), although there is no such association for the variations separately. The variations rs10519612 and rs1059613 in a recessive pattern of inheritance were associated with hyperdiploidy (p = 0.048). Analyzed genetic variations had no impact on other clinical features and treatment response (assessed by the minimal residual disease) in our study.  相似文献   

8.
Between 1981 and 1996, several interventional studies proved the efficacy of periconceptional folic acid supplementation in the prevention of neural tube closure defects (NTCD), first in women at risk (with a previous case of NTCD) and also in women of the general population in age to become pregnant. The poor observance of this supplementation led several countries (USA, Canada, Chile...) to decide mandatory folic acid fortification of cereals, which permitted a 30% (USA) to 46% (Canada) reduction in the incidence of NTCD. Moreover, this benefit was accompanied by a diminished incidence of several other malformations and of stroke and coronary accidents in elderly people. However, several papers drew attention to an increased risk of colorectal and breast cancer in relation with high blood folate levels and the use of folic acid supplements. A controlled interventional study showed a higher rate of recurrence of colic adenomas and a higher percentage of advanced adenomas in subjects receiving 1mg/day of folic acid. A recent study demonstrated an abrupt reversal of the downward trend in colorectal cancer 1 year after the beginning of cereal folic acid fortification in the USA and Canada. Two studies also reported impaired cognitive functions in elder persons with defective vitamin B(12) status. Taken in aggregate, these studies question the wisdom of a nationwide, mandatory, folic acid fortification of cereals. As of today, despite their limited preventive efficacy, a safe approach is to keep our current French recommendations and to increase the awareness of all caregivers, so as to improve the observance of these recommendations.  相似文献   

9.
We analyzed the role of maternal C677T mutation in methylenetetrahydrofolate reductase (MTHFR) gene on spina bifida development in newborns. A total of 115 mothers who had given birth to a spina bifida child (SB mothers) gave 10 mL of blood together with written informed consent. The genotype distribution of C677T mutation was assessed and compared with that of the 4517 control individuals. The prevalence of the homozygous genotype (TT) among SB mothers was not significantly different from that among the controls (odds ratio [OR] = 0.65; 95% confidence interval [CI] = 0.31–1.25; P = 0.182), suggesting that MTHFR 677TT genotype in Japan is not associated with spina bifida development in newborns. The T allele frequency was not increased in SB mothers (34.8%) as compared to that of the control individuals (38.2%). Further, the internationally reported association between the two groups was found to be similar in all 15 countries studied except the Netherlands, where the TT genotype was found to be a genetic risk factor for spina bifida. For the prevention of affected pregnancy every woman planning to conceive has to take folic acid supplements 400 μg a day and the government is asked to take action in implementing food fortification with folic acid in the near future. In conclusion, it is not necessary for Japanese women to undergo genetic screening C677T mutation of the MTHFR gene as a predictive marker for spina bifida prior to pregnancy, because the TT genotype is not a risk factor for having an affected infant.  相似文献   

10.
Folate insufficiency during the periconceptional period increases the risk of neural tube defects (NTDs) in offspring, and folic acid supplementation substantially reduces the risk. Widespread large‐scale folic acid supplementation (0.4‐mg folic acid tablet) has been adopted as a main strategy to prevent NTDs in China since 2009. We examined folate concentrations in plasma and red blood cells (RBCs) of pregnant women and the factors associated with blood folate concentrations in a population with a high prevalence of NTDs in northern China. A cross‐sectional survey was conducted in 2014, and 1,107 pregnant women were recruited from 11 county or city maternal and child health centres across Shanxi province. Microbiological assays were used to determine folate concentrations. Factors associated with blood folate insufficiency were identified. The median (25th and 75th percentiles) folate concentrations were 28.4 (17.6, 45.2) nmol L?1 and 1,001.2 (658.7, 1,402.5) nmol L?1 in plasma and RBCs, respectively. According to the proposed RBC (906 nmol L?1) concentrations for optimal NTD prevention, 42.4% participants had RBC folate insufficiency. Rural women had a higher proportion of folate insufficiency than urban women. Folic acid supplementation was the only factor associated with RBC folate insufficiency. A large proportion of women had RBC folate concentrations that are not optimal for the prevention of NTDs despite free access to folic acid supplements. Actions that aim to improve folic acid supplementation compliance are needed to reach the full potential of the nationwide folic acid supplementation programme in terms of NTD prevention.  相似文献   

11.
Published literatures report controversial results about the association of folic acid–containing multivitamins with gestational hypertension and pre‐eclampsia. A comprehensive search was performed to identify related prospective studies to assess the effect of folic acid fortification on gestational hypertension and pre‐eclampsia. The Q test and I2 statistic were used to examine between‐study heterogeneity. Fixed or random effects models were selected based on study heterogeneity. A funnel plot and modified Egger linear regression test were used to estimate publication bias. Eleven studies conformed to the criteria. Pooled results indicated that folic acid fortification alone was not associated with the occurrence of gestational hypertension [relative risk (RR) = 1.03, 95% confidence interval (CI): 0.98–1.09, P = 0.267] and pre‐eclampsia (RR = 0.99, 95% CI: 0.90–1.08, P = 0.738). However, supplementation of multivitamins containing folic acid could prevent gestational hypertension (RR = 0.57, 95% CI: 0.43–0.76, P < 0.001) and pre‐eclampsia (RR = 0.64, 95% CI: 0.48–0.84, P = 0.001). The difference between folic acid fortification alone and multivitamins containing folic acid was significant. This meta‐analysis suggests that periconceptional multivitamin supplementation with appropriate dose, not folic acid alone, is an appropriate recommendation for pregnant women. The effect should be further confirmed by conducting large‐scale randomised controlled trials.  相似文献   

12.
Methotrexate (MTX) is an antifolate that inhibits cell division by reducing intracellular amounts of reduced tetrahydrofolates. Of 53 children with acute lymphoblastic leukemia (ALL) in maintenance treatment with MTX and 6-mercaptopurine (6-MP), 25 had received daily folic acid supplements in vitamin tablets containing 75-200 micrograms folic acid for at least the preceding 3-month period. Experimental data have shown that increased folate concentrations intracellularly inhibit MTX metabolism and toxicity. Therefore we found it relevant to investigate the extent to which folic acid supplements affect hematological tolerance to MTX and 6-MP in children during maintenance therapy for ALL. The erythrocyte folate (ery-folate) concentration was significantly higher in children who received extra folic acid than in those who did not (p less than 0.001). The ery-folate in MTX-treated children was only marginally reduced compared with the controls. The erythrocyte methotrexate (ery-MTX) concentration correlated with the weekly dose of MTX but not with any of the investigated hematological parameters. Children who received vitamin tablets containing folic acid had higher thrombocyte counts (p = 0.0056), higher leukocyte counts (p = 0.06), higher neutrophil counts (p = 0.05), and lower erythrocyte mean cell volumes (p = 0.05) than children who received no folic acid. We conclude that folic acid supplements of 75-200 micrograms/day affect the proliferative capacity of the bone marrow. Since none of the children was folate deficient as judged by the ery-folate, we recommend that vitamins given to children in maintenance treatment with MTX and 6-MP for ALL should not contain folic acid.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

13.
目的 探讨母亲还原叶酸载体(reduced folate carrier,RFC)基因多态性与子代先天性心脏病(congenital heart disease,CHD)的关系.方法 采用基于医院的病例对照研究,以2017年11月至2020年3月于湖南省儿童医院心胸外科就诊的683例CHD婴儿的母亲为病例组,以同期在该...  相似文献   

14.
Neural tube defects : Prevention by folic acid and other vitamins   总被引:3,自引:0,他引:3  
Folic acid has been demonstrated in clinical trials to reduce significantly the recurrence (and probably occurrence) of neural tube defects (NTD). In the U.K., there has been no decline in prevalence of NTD since the publication of the findings with folic acid. This article examines a series of questions relating to the action of folic acid, with emphasis on the use of mouse models as a source of experimental information which cannot easily be obtained by direct study of humans. Several mouse genetic NTD models exhibit sensitivity to prevention by folic acid, whereas other mice which develop morphologically similar NTD are resistant. Folic acid normalises neurulation in the sensitive mouse strains, providing evidence for a direct effect on the developing embryo, not on the pregnant female. Mouse studies do not support the proposed action of folic acid in encouraging thein utero demise of affected fetuses (i.e. terathanasia). Polymorphic variants of several folate-related enzymes have been shown to influence risk of NTD in humans and an inherited abnormality of folate metabolism has been demonstrated in one mouse NTD model. However, the biochemical basis of the action of folic acid in preventing NTD remains to be determined in detail. NTD in one folate-resistant mouse strain can be prevented by myoinositol, bothin utero andin vitro, raising the possibility of a therapeutic role also in humans. Gene-gene interactions seem likely to underlie the majority of NTD, suggesting that poly-therapy involving folic acid and other agents, such as myo-inositol, may prove more effective in preventing NTD than folic acid treatment alone.  相似文献   

15.
Background: Congenital heart defects (CHD) are present in most, but not all, cases of Down syndrome (DS). The presence of methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms has been reported as a risk factor for CHD in DS. The aims of the present study were to assess (i) the frequency of MTHFR C677T and A1298C polymorphisms in DS individuals in the Croatian population; (ii) the relationship between the two maternal MTHFR polymorphisms and CHD‐affected DS children; and (iii) the transmission frequencies of the variant alleles of the two MTHFR polymorphisms in CHD‐affected DS. Methods: The study population included 112 DS subjects and 221 controls. CHD were present in 48% of the DS subjects (54/112). The mothers of 107 DS individuals were available for the study; none was a periconceptional folic acid user. Allele transmission was analyzed in 34 complete parent–offspring triads. Results: The frequencies of the allele, individual, and combined genotypes of MTHFR C677T and A1298C in DS subjects were not statistically different compared to the normal healthy Croatian controls. The maternal MTHFR polymorphisms were not found to be a risk factor for DS‐related CHD. The allele transmission of the two MTHFR polymorphisms showed no deviations from random segregation. Conclusions: Because the fetus is lost in a great proportion of trisomy 21 pregnancies, both maternal and fetal, not only live‐born MTHFR C677T and A1298C, as well as maternal nutrition and lifestyle during pregnancy, should be analyzed to asses the impact on CHD in DS.  相似文献   

16.
Neural tube defects (NTDs) are the second most common group of serious birth defects. Although folic acid has been shown to reduce effectively the risk of NTDs and measures have been taken to increase the awareness, knowledge, and consumption of folic acid, the full potential of folic acid to reduce the risk of NTDs has not been realized in most countries. To understand the economic burden of NTDs and the economic impact of preventing NTDs with folic acid, a systematic review was performed on relevant studies. A total of 14 cost of illness studies and 10 economic evaluations on prevention of NTDs with folic acid were identified. Consistent findings were reported across all of the cost of illness studies. The lifetime direct medical cost for patients with NTDs is significant, with the majority of cost being for inpatient care, for treatment at initial diagnosis in childhood, and for comorbidities in adult life. The lifetime indirect cost for patients with spina bifida is even greater due to increased morbidity and premature mortality. Caregiver time costs are also significant. The results from the economic evaluations demonstrate that folic acid fortification in food and preconception folic acid consumption are cost-effective ways to reduce the incidence and prevalence of NTDs. This review highlights the significant cost burden that NTDs pose to healthcare systems, various healthcare payers, and society and concludes that the benefits of prevention of NTDs with folic acid far outweigh the cost. Further intervention with folic acid is justified in countries where the full potential of folic acid to reduce the risk of NTDs has not been realized.  相似文献   

17.
Good clinical practice recommends folic acid supplementation 1 month prior to pregnancy and during the first trimester to prevent congenital malformations. However, high rates of fetal growth and development in later pregnancy may increase the demand for folate. Folate and vitamins B12 and B6 are required for DNA synthesis and cell growth, and are involved in homocysteine metabolism. The primary aim of this study was to determine if maternal folate, vitamin B12, vitamin B6 and homocysteine concentrations at 18–20 weeks gestation are associated with subsequent adverse pregnancy outcomes, including pre‐eclampsia and intrauterine growth restriction (IUGR). The secondary aim was to investigate maternal B vitamin concentrations with DNA damage markers in maternal lymphocytes. A prospective observational study was conducted at the Women's and Children's Hospital, Adelaide, South Australia. One hundred and thirty‐seven subjects were identified prior to 20 weeks gestation as at high or low risk for subsequent adverse pregnancy outcome by senior obstetricians. Clinical status, dietary information, circulating micronutrients and genome damage biomarkers were assessed at 18–20 weeks gestation. Women who developed IUGR had reduced red blood cell (RBC) folate (P < 0.001) and increased plasma homocysteine concentrations (P < 0.001) compared with controls. Maternal DNA damage, represented by micronucleus frequency and nucleoplasmic bridges in lymphocytes, was positively correlated with homocysteine (r = 0.179, P = 0.038 and r = 0.171, P = 0.047, respectively). Multivariate regression analysis revealed RBC folate was a strong predictor of IUGR (P = 0.006). This study suggests that low maternal RBC folate and high homocysteine values in mid pregnancy are associated with subsequent reduced fetal growth.  相似文献   

18.
Background: Maternal nutrition during pregnancy has been linked with fetal brain development and psychopathology in the offspring. We examined for associations of maternal folate status and dietary intake during pregnancy with brain growth and childhood behavioural difficulties in the offspring. Methods: In a prospective cohort study, maternal red blood cell folate (RCF) was measured at 14 weeks of pregnancy and total folate intake (TFI) from food and supplements was assessed in early and late pregnancy. The offspring’s head circumference and body weight were measured at birth and in infancy, and 100 mothers reported on children’s behavioural difficulties at a mean age of 8.75 years using the Strengths and Difficulties Questionnaire. Results: Lower maternal RCF and TFI in early pregnancy were associated with higher childhood hyperactivity (RCF: beta = ?.24; p = .013; TFI: beta = ?.24; p = .022) and peer problems scores (RCF: beta = ?.28; p = .004; TFI: beta = ?.28; p = .009) in the offspring. Maternal gestational RCF was positively associated with head circumference at birth (adjusted for gestational age), and mediation analyses showed significant inverse indirect associations of RCF with hyperactivity/inattention and peer problems via fetal brain growth. Adjustment for mother’s smoking and drinking alcohol during pregnancy did not change the results. Conclusions: Although the associations are small and residual confounding is possible, our data provide preliminary support for the hypothesis that lower folate status in early pregnancy might impair fetal brain development and affect hyperactivity/inattention and peer problems in childhood.  相似文献   

19.
Low vitamin B12 and folate levels in expectant mothers may lead to low stores in babies. The aim of this study was to determine the frequencies of vitamin B12 and folate deficiencies in pregnant women and neonates, and to assess the effect of maternal vitamin status on babies’ vitamin levels in the Aegean region of Turkey, where the Mediterranean diet (mainly fresh fruits and vegetables) is adopted. We studied 72 pregnant women and their singleton-term babies. Venous blood samples of expectant mothers were collected 1 h before delivery and cord blood of babies were obtained at birth. The mean vitamin B12 in maternal and cord blood serum was 163.1 ± 72.0 pg/mL and 146.2 ± 102.5 pg/mL, and the mean folate, 9.8 ± 4.8 ng/mL and 15.8 ± 3.8 ng/mL, respectively. There were statistically significant correlation between maternal and cord blood serum vitamin B12 (r = 0.61, P = .04) and folate levels (r = 0.65, P < .001). 70.8% of the mothers and 83.9% of the babies were vitamin B12 deficient (<200 pg/mL). Neither group showed folate deficiency. The mean level of vitamin B12 in mothers significantly varied by the type of diet (241.6 (72.1) pg/mL versus 155.9 (68.2) pg/mL; P = .012). Vitamin B12 deficiency in pregnant women and neonates may be a public health problem in our community. The Mediterranean diet in these vulnerable groups may be an aggravating factor for vitamin B12 deficiency. Prenatal screening of all expectant mothers, prenatal supplementation of vitamin B12, and an increase in animal-source food intake may improve expectant mother's vitamin B12 level.  相似文献   

20.
Neural tube defects(NTDs) are a group of congenital malformations of the central nervous system that are caused by the closure failure of the embryonic neural tube by the 28 th day of conception. Anencephaly and spina bifida are the two major subtypes. Fetuses with anencephaly are often stillborn or electively aborted due to prenatal diagnosis, or they die shortly after birth. Most infants with spina bifida are live-born and, with proper surgical treatment, can survive into adulthood. However, these children often have life-long physical disabilities. China has one of the highest prevalence of NTDs in the world. Inadequate dietary folate intake is believed to be the main cause of the cluster. Unlike many other countries that use staple fortification with folic acid as the public health strategy to prevent NTDs, the Chinese government provides all women who have a rural household registration and who plan to become pregnant with folic acid supplements, free of charge, through a nation-wide program started in 2009. Two to three years after the initiation of the program, the folic acid supplementation rate increased to 85% in the areas of the highest NTD prevalence. The mean plasma folate level of women during early and mid-pregnancy doubled the level before the program was introduced. However, most women began taking folic acid supplements when they knew that they were pregnant. This is too late for the protection of the embryonic neural tube. In a postprogram survey of the women who reported folic acid supplementation, less than a quarter of the women began taking supplements prior to pregnancy, indicating that the remaining three quarters of the fetuses remained unprotected during the time of neural tube formation. Therefore, staple food fortification with folic acid should be considered as a priority in the prevention of NTDs.  相似文献   

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