From “How to Teach” to “How to Learn”

Dialectics of Nature, a compulsory course for science and engineering postgraduate students, “service-oriented” teachers should how to teach, and students should how to learn, which are two bidirectional dialectical core units on Dialectics of Nature to achieve a fundamental teaching purpose

Molecular cloning and tissue expression of the fatty acid-binding protein (Es-FABP) gene in female Chinese mitten crab (Eriocheir sinensis)

<p>Abstract</p> <p>Background</p> <p>Fatty acid-binding proteins (FABPs), small cytosolic proteins that function in the uptake and utilization of fatty acids, have been extensively studied in higher vertebrates while invertebrates have received little attention despite similar nutritional requirements during periods of reproductive activity.</p> <p>Results</p> <p>Therefore, a cDNA encoding <it>Eriocheir sinensis </it>FABP (Es-FABP) was cloned based upon EST analysis of a hepatopancreas cDNA library. The full length cDNA was 750 bp and encoded a 131 aa polypeptide that was highly homologous to related genes reported in shrimp. The 9108 bp <it>Es-FABP </it>gene contained four exons that were interrupted by three introns, a genomic organization common among FABP multigene family members in vertebrates. Gene expression analysis, as determined by RT-PCR, revealed the presence of <it>Es-FABP </it>transcripts in hepatopancreas, hemocytes, ovary, gills, muscle, thoracic ganglia, heart, and intestine, but not stomach or eyestalk. Real-time quantitative RT-PCR analysis revealed that <it>Es-FABP </it>expression in ovary, hemocytes, and hepatopancreas was dependent on the status of ovarian development, with peak expression observed in January.</p> <p>Conclusions</p> <p>Evidence provided in the present report supports a role of Es-FABP in lipid transport during the period of rapid ovarian growth in <it>E. sinensis</it>, and indirectly confirms the participation of the hepatopancreas, ovary, and hemocytes in lipid nutrient absorption and utilization processes.</p

Association of basal serum testosterone levels with ovarian response and in vitro fertilization outcome

<p>Abstract</p> <p>Background</p> <p>To evaluate basal testosterone (T) levels during follicular phase of the menstrual cycle as a predictor for ovarian response and in vitro fertilization (IVF) outcome.</p> <p>Method</p> <p>We analyzed data retrospectively from hospital-based IVF center including one thousand two hundred and sixty Chinese Han women under their first IVF cycle reached the ovum pick-up stage, without polycystic ovary syndrome (PCOS) or endometriosis undergoing long IVF protocol. Patients were divided into 2 groups. Group 1: patients with diminished ovarian reserve (basal FSH >10 IU/L) (n = 187); Group 2: patients with normal ovarian reserve (basal FSH < = 10 IU/L) (n = 1073). We studied the association of basal T levels with ovarian response and IVF outcome in the two groups. Long luteal down-regulation protocol was used in all patients, that is, the gonadotropin releasing hormone agonist was administered in the midluteal phase of the previous cycle and use of recombinant FSH was started when satisfactory pituitary desensitization was achieved.</p> <p>Results</p> <p>Basal T levels were markly different between pregnant and non-pregnant women in Group 1; whereas not in Group 2. A testosterone level of 47.85 ng/dl was shown to predict pregnancy outcome with a sensitivity of 52.8% and specificity of 65.3%; and the basal T was correlated with the numbers of large follicles (> 14 mm) on HCG day in Group 1. Significantly negative correlations were observed between basal T, days of stimulation and total dose of gonadotropins after adjusting for confounding factors in both groups.</p> <p>Conclusion</p> <p>In women with diminished ovarian reserve, basal T level was a predictor for the number of large follicles on HCG day and pregnancy outcome; but could not in those with normal serum FSH. Basal T levels were associated with both days of stimulation and total dose of gonadotropins, indicating that lower level of T might relate with potential ovarian poor response.</p

Enhanced nitrogen photofixation over LaFeO3 via acid treatment

The N2 photofixation presents a green and eco-friendly ammonia synthesis approach. However, present strategies for light-induced N2 activation suffer from low efficiency and instability, largely hindering the development of this technology. Herein, we report the LaFeO3 co-optimization of N2 activation as well as subsequent photoinduced protonation with the further phosphate acid treatment. Efficient ammonia evolution rate reached 250 μmol g–1 h–1 over LaFeO3 under simulated sunlight with appropriate acid treatment. The enhancement of phosphate modified samples was mainly attributed to the “pull and push” effect. The hydrogen bonding centers and transition metals (Fe) served as two separation active sites, which improves the adsorption and activation of dinitrogen. In addition, the facilitation of H2O dissociation was also achieved after phosphate modification. These results suggested an alternative N2 photofixation strategy of traditional organic and precious metallic additives for efficient ammonia synthesis