首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   48篇
  免费   4篇
儿科学   1篇
妇产科学   25篇
基础医学   7篇
口腔科学   4篇
临床医学   1篇
内科学   7篇
神经病学   1篇
外科学   1篇
预防医学   2篇
药学   3篇
  2021年   1篇
  2019年   1篇
  2018年   5篇
  2017年   4篇
  2016年   8篇
  2015年   5篇
  2014年   3篇
  2013年   4篇
  2012年   3篇
  2011年   3篇
  2010年   1篇
  2009年   2篇
  2008年   2篇
  2007年   3篇
  2005年   1篇
  2003年   2篇
  2002年   1篇
  2000年   1篇
  1988年   1篇
  1969年   1篇
排序方式: 共有52条查询结果,搜索用时 15 毫秒
21.
Objective: To determine umbilical cord blood total antioxidant capacity (TAC), ferric reducing antioxidant power (FRAP), thiobarbituric acid-reacting substances (TBARS), advanced glycation end products (AGEs) and markers of oxidative stress in pregnancies complicated by preterm prelabor rupture of membranes (PPROM) and their associations with microbial invasion of the amniotic cavity (MIAC) and/or histological chorioamnionitis (HCA), funisitis and selected aspects of short-term neonatal morbidity.

Materials and methods: One hundred and sixty-five women with singleton pregnancies complicated by PPROM were included in this study. Blood samples were obtained by venipuncture from the umbilical cord vein after the delivery of the newborn. The umbilical cord blood concentrations of TAC, FRAP, TBARS and AGEs were measured.

Results: The presence of MIAC, HCA and funisitis did not show differences in the umbilical cord blood TAC, FRAP, TBARS and AGEs concentrations. Positive correlations were found between the gestational age at sampling and umbilical cord blood TAC and AGEs concentrations (TAC: rho?=?0.26; p?=?0.001; AGEs: rho?=?0.35; p?<?0.0001). There was no association between umbilical cord blood TAC, FRAP, TBARS and AGEs concentrations and selected aspects of short-term neonatal morbidity.

Conclusions: Oxidative stress is associated with PPROM, as indicated by the presence of markers tested in the umbilical cord blood; however, the evaluated oxidative stress markers are not influenced by the presence of MIAC and/or HCA, and funisitis or subsequent development of selected aspects of short-term neonatal morbidity.  相似文献   
22.
Recently, we described B-cell precursor acute lymphoblastic leukemia (BCP-ALL) subtype with an early switch to the monocytic lineage and the loss of the B-cell immunophenotype, including CD19 expression. Thus far, the genetic background has remained unknown. Among 726 children consecutively diagnosed with BCP-ALL, 8% patients experienced a switch detectable by flow cytometry (FC). Using exome and RNA sequencing, the switch was found to positively correlate with three different genetic subtypes: PAX5-P80R mutation (five cases with switch of five), rearranged (DUX4r) (30 cases of 41) and rearranged (ZNF384r) (four cases of ten). Expression profiles or phenotypic patterns correlated with genotypes, but within each genotype no cases who subsequently switched could be indentified. If switching was not taken into account, the B-cell-oriented FC assessment underestimated the minimal residual disease level. For patients with PAX5-P80R, a discordance between FC-determined and polymerase chain reactiondetermined minimal residual disease was found on day 15, resulting from a rapid loss of the B-cell phenotype. Discordance on day 33 was observed in all the DUX4r, PAX5-P80R and ZNF384r subtypes. Importantly, despite the substantial phenotypic changes, possibly even challenging the appropriateness of BCP-ALL therapy, the monocytic switch was not associated with a higher incidence of relapse and poorer prognosis in patients undergoing standard ALL treatment.  相似文献   
23.
Objective: To determine amniotic fluid total antioxidant capacity (TAC), ferric-reducing antioxidant power (FRAP) and thiobarbituric acid-reacting substances (TBARS), markers of oxidative stress, in pregnancies complicated by preterm prelabor rupture of membranes (pPROM) and their correlation to microbial invasion of the amniotic cavity (MIAC) and/or histological chorioamnionitis (HCA).

Methods: One-hundred thirty-eight women with singleton pregnancies complicated by pPROM were included in this study. Amniotic fluid was collected by transabdominal amniocentesis at the time of admission and amniotic fluid concentrations of TAC, FRAP and TBARS were measured.

Result: The presence of MIAC and/or HCA did not show any significant differences in the amniotic fluid TAC, FRAP and TBARS concentrations. Positive correlations between gestational age at sampling and amniotic fluid TAC and FRAP concentrations were found (TAC: rho?=?0.32; p?=?0.0002; FRAP: rho?=?0.36; p?<?0.0001). A negative correlation between gestation age at sampling and amniotic fluid TBARS concentrations was identified (rho?=?–0.25; p?=?0.004).

Conclusions: Oxidative stress is associated with pPROM as indicated by the presence of markers tested in the amniotic fluid; however, oxidative stress markers tested are not influenced by the presence of MIAC or HCA.  相似文献   

24.
25.
Recent evidence suggests that energy metabolism contributes to molecular mechanisms controlling stem cell identity. For example, human embryonic stem cells (hESCs) receive their metabolic energy mostly via glycolysis rather than mitochondrial oxidative phosphorylation. This suggests a connection of metabolic homeostasis to stemness. Nicotinamide adenine dinucleotide (NAD) is an important cellular redox carrier and a cofactor for various metabolic pathways, including glycolysis. Therefore, accurate determination of NAD cellular levels and dynamics is of growing importance for understanding the physiology of stem cells. Conventional analytic methods for the determination of metabolite levels rely on linear calibration curves. However, in actual practice many two-enzyme cycling assays, such as the assay systems used in this work, display prominently nonlinear behavior. Here we present a diaphorase/lactate dehydrogenase NAD cycling assay optimized for hESCs, together with a mechanism-based, nonlinear regression models for the determination of NAD+, NADH, and total NAD. We also present experimental data on metabolic homeostasis of hESC under various physiological conditions. We show that NAD+/NADH ratio varies considerably with time in culture after routine change of medium, while the total NAD content undergoes relatively minor changes. In addition, we show that the NAD+/NADH ratio, as well as the total NAD levels, vary between stem cells and their differentiated counterparts. Importantly, the NAD+/NADH ratio was found to be substantially higher in hESC-derived fibroblasts versus hESCs. Overall, our nonlinear mathematical model is applicable to other enzymatic amplification systems.  相似文献   
26.
27.

Purpose

To report a case of monozygotic monochorial diamniotic twins with discordant karyotypes.

Methods and results

The pregnancy was achieved following a treatment cycle with intracytoplasmic sperm injection (ICSI) and preimplantation genetic screening (PGS) for chromosomes X, Y, 13, 16, 18, 21, 22. One embryo euploid for studied chromosomes was transferred. Prenatal ultrasonography revealed monozygotic twins. One fetus had growth retardation, multiple organ abnormalities and polyhydramnion. The other twin had normal ultrasound appearance. Delivery on week 29 of gestation resulted in the birth of two females, a stillborn twin with karyotype 45,XX,-13[12]/46,XX,r(13)[3] and a healthy twin with normal karyotype.

Conclusions

The discordance in the twins’ karyotypes originated from a mosaic embryo. Structural chromosomal abnormality of the affected twin could not be revealed using standard PGS investigation. Embryo splitting occurred probably due to apoptotic process in an early stage of embryo development. Apoptosis represents one of the possible mechanisms which can explain the embryo twinning process globally.  相似文献   
28.
Objective: To determine if cervical fluid interleukin (IL)-6 concentrations in women with preterm prelabor rupture of membranes (PPROM) allows identification of microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation (IAI).

Methods: One hundred forty-four women with singleton pregnancies complicated by PPROM were included in this prospective cohort study. Cervical and amniotic fluids were collected at the time of admission and concentrations of IL-6 were measured using an ELISA and point-of-care test, respectively. Cervical fluid was obtained using a Dacron polyester swab and amniotic fluid was obtained by transabdominal amniocentesis. MIAC was diagnosed based on a positive PCR result for Ureaplasma species, M. hominis, and/or C. trachomatis and/or by positivity for the 16?S rRNA gene. IAI was defined as amniotic fluid point-of-care IL-6 concentrations ≥745?pg/mL. The women were assigned to four subgroups based on the presence of MIAC and/or IAI: microbial-associated IAI (both MIAC and IAI), sterile IAI (IAI alone), MIAC alone, and without either MIAC or IAI.

Results: (1) Women with microbial-associated IAI had higher cervical fluid IL-6 concentrations (median 560?pg/mL) than did women with sterile IAI (median 303?pg/mL; p?=?.001), women with MIAC alone (median 135?pg/mL; p?=?.0004), and women without MIAC and IAI (median 180?pg/mL; p?=?.0001). (2) No differences were found in cervical fluid IL-6 concentrations among women with sterile IAI, with MIAC alone, and without MIAC and IAI. (3) A positive correlation was observed between cervical fluid IL-6 concentrations and the amount of Ureaplasma species in amniotic fluid (copies DNA/mL; rho?=?0.57, p?p?Conclusions: The presence of microbial-associated IAI is associated with the highest cervical fluid IL-6 concentrations. Cervical IL-6 can be helpful in the identification of microbial-associated IAI.  相似文献   
29.
30.
Abstract: Newly developed acetylcholinesterase reactivators K117 [1,5‐bis(4‐hydroxyiminomethylpyridinium)‐3‐oxapentane dichloride] and K127 [(1‐(4‐hydroxyiminomethylpyridinium)‐5‐(4‐carbamoylpyridinium)‐3‐oxapentane dibromide)] were tested for their potency to reactivate tabun‐inhibited human brain cholinesterases. Pralidoxime and trimedoxime were chosen as standard reference reactivators. Human tissue was used, as that was closer on the real treatment of human beings. As a result, oxime K127 was found as the best tested reactivator according to the constant kr, characterizing the overall reactivation process. On the contrary, the maximal reactivation ability expressed as percentage of reactivation was the best for trimedoxime. This differences were caused as a result of using the enzyme from different species. Due to this, experiments on human tissue should be conducted after in vitro and in vivo tests on animals to eliminate such important failures of promising oximes.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号