Transition-metal difluorocarbene complexes.

Although transition metal carbenes have found widespread applications and difluorocarbene has served as a versatile intermediate, it is still quite challenging to make use of transition-metal difluorocarbenes in synthetic chemistry due to their unpredictable reactivities. In this Highlight, we review recent developments in the transition-metal-catalyzed or -mediated transfer of difluorocarbene and the reactivies and conversions of transition-metal difluorocarbene complexes. We start with the MCF2 bonding, then provide the progress in the transfer of difluorocarbene, and finally briefly discuss the conversions of MCF2 into other metal complexes. The understanding of the interesting reactivities of MCF2 may help design the catalytic transfer of difluorocarbene for various reactions.

Second Morning ACR Could Be the Alternative to First Morning ACR to Assess Albuminuria in Elderly Population.

BACKGROUND: Albumin/creatinine ratio (ACR) from a first morning urine is recommended as a early indicator for diabetic nephropathy. However, it is not always feasible to collect the first morning urine for outpatients. We aimed to explore whether ACR from a second morning urine had a good consistency with that from a first morning urine to predict albuminuria in Chinese elderly citizens. METHOD: One hundred and ninety-one elderly citizens (≧60 years old) from Junliangcheng community, Dongli district, Tianjin, China were included. A first and second morning urine was collected from each participants, successfully and detected the urinary albumin and creatinine of each urine sample. Albumin to creatinine ratio from a first morning urine (ACR1) was compared with that from a second morning urine (ACR2), and the ability of ACR1 and ACR2 to predict albuminuria was assessed. RESULT: ACR1 and ACR2 were highly correlated (r = 0.901), especially in male and hypertension group (r = 0.938 and 0.904). The slope and intercept were 0.93 and 0.11 after log-transformed. And there was no statistical difference between values of ACR1 and ACR2 (P = 0.271). Overall, 26.2% participants were detected with albuminuria when judged by ACR1 and 28.3% by ACR2. A good concordance of ACR category (normal or albuminuria) was found between ACR1 and ACR2 (Kappa value = 0.815 in overall; in male and hypertension group were 0.900 and 0.850). CONCLUSION: A second morning urine ACR could be the alternative to a first morning urine ACR for albuminuria detection in elderly population.

[Effects of biochar on the micro-ecology of tobacco-planting soil and physiology of flue-cured tobacco].

Biochar is one of the research hotspots in the field of the agroforestry waste utilization. A field experiment was carried out to investigate the effects of different amounts of tobacco stem biochar (0, 1, 10, 50 t · hm⁻²) on soil micro-ecology and physiological properties of flue-cured tobacco. The results showed that soil water content (SWC) increased at all tobacco growth stages as the amounts of biochar applications increased. There were significant differences of SWC between the treatment of 50 t · hm⁻² and other treatments at the period of tobacco vigorous growth. As the application of biochar increased, the total soil porosity and capillary porosity increased, while soil bacteria, actinomyces, fungi amount increased firstly and then decreased. The amount of soil bacteria, actinomyces, fungi reached the maximum at the treatment of 10 t · hm⁻². Soil respiration rate (SRR) at earlier stage increased with the increase of biochar application. Compared with the control, SSR under biochar treatments increased by 7.9%-36.9%, and there were significant differences of SRR between high biochar application treatments (50 t · hm⁻² and 10 t · hm⁻²) and the control. Biochar improved leaf water potential, carotenoid and chlorophyll contents. Meanwhile, the dry mass of root, shoot and total dry mass under biochar application were higher than that of the control. These results indicated that the biochar played active roles in improving tobacco-planting soil micro-ecology and regulating physiological properties of flue-cured tobacco.

Comparative transcriptome analysis of tobacco (Nicotiana tabacum) leaves to identify aroma compound-related genes expressed in different cultivated regions.

To identify genes that are differentially expressed in tobacco in response to environmental changes and to decipher the mechanisms by which aromatic carotenoids are formed in tobacco, an Agilent Tobacco Gene Expression microarray was adapted for transcriptome comparison of tobacco leaves derived from three cultivated regions of China, Kaiyang (KY), Weining (WN) and Tianzhu (TZ). A total of 1,005 genes were differentially expressed between leaves derived from KY and TZ, 733 between KY and WN, and 517 between TZ and WN. Genes that were upregulated in leaves from WN and TZ tended to be involved in secondary metabolism pathways, and included several carotenoid pathway genes, e.g., NtPYS, NtPDS, and NtLCYE, whereas those that were down-regulated tended to be involved in the response to temperature and light. The expression of 10 differentially expressed genes (DEGs) was evaluated by real-time quantitative polymerase chain reaction (qRT-PCR) and found to be consistent with the microarray data. Gene Ontology and MapMan analyses indicate that the genes that were differentially expressed among the three cultivated regions were associated with the light reaction of photosystem II, response to stimuli, and secondary metabolism. High-performance liquid chromatography (HPLC) analysis showed that leaves derived from KY had the lowest levels of lutein, ß-carotene, and neoxanthin, whereas the total carotenoid content in leaves from TZ was greatest, a finding that could well be explained by the expression patterns of DEGs in the carotenoid pathway. These results may help elucidate the molecular mechanisms underlying environmental adaptation and accumulation of aroma compounds in tobacco.

Methodological evaluation and comparison of five urinary albumin measurements.

BACKGROUND: Microalbuminuria is an indicator of kidney damage and a risk factor for the progression kidney disease, cardiovascular disease, and so on. Therefore, accurate and precise measurement of urinary albumin is critical. However, there are no reference measurement procedures and reference materials for urinary albumin. METHODS: Nephelometry, turbidimetry, colloidal gold method, radioimmunoassay, and chemiluminescence immunoassay were performed for methodological evaluation, based on imprecision test, recovery rate, linearity, haemoglobin interference rate, and verified reference interval. Then we tested 40 urine samples from diabetic patients by each method, and compared the result between assays. RESULTS: The results indicate that nephelometry is the method with best analytical performance among the five methods, with an average intraassay coefficient of variation (CV) of 2.6%, an average interassay CV of 1.7%, a mean recovery of 99.6%, a linearity of R=1.00 from 2 to 250 mg/l, and an interference rate of <10% at haemoglobin concentrations of <1.82 g/l. The correlation (r) between assays was from 0.701 to 0.982, and the Bland-Altman plots indicated each assay provided significantly different results from each other. CONCLUSION: Nephelometry is the clinical urinary albumin method with best analytical performance in our study.

[Surgical treatment of tarsometatarsal joints injury].

OBJECTIVE: To summmarize the clinical experience of open reduction and internal fixation for the treatment of tarsometatarsal joint injury ane evaluate the effects of operative treatment to tarsometatarsal joint injury. METHODS: From March to July in 2009,9 patients with tarsometatarsal joint injury were treated by open reduction and internal fixation included 7 males and 2 females with an average age of 33.5 years old ranging from 20 to 47 years. According to Quenu-Kuss classification, there were 5 cases of type A, 3 of type B, 1 of type C. All patients were treated by cannulated screws and Kirschner wires through 1 to 2 microtubule straight incision on dorsum of foot. The foot function were assessed by American Orthopaedic Foot and Ankle Society (AOFAS) midfoot score. RESULTS: All patients were followed up for 5 to 12 months with an average of 8 months. Complications concluded 1 case with infection, 1 case with post-traumatic arthritis. The failure of Kirschner wires was not discovered in 9 cases. According to AOFAS system,the total scores increased from preoperative (15.5 +/- 4.2) to postoperative (92.0 +/- 5.2) (t = -45.95, P < 0.01). The results were excellent in 7 cases, good in 1, and poor in 1. CONCLUSION: Open reduction and internal fixation for the reatment of tarsometatarsal joint injury should have satisfying results.