苎麻光合生理生态特性研究

以大田栽培的苎麻植株为材料,用TPS-2便携式光合作用测定系统测定自然条件下生长的苎麻叶片的光合气体交换参数,以及光响应曲线和CO2响应曲线,并通过回归和相关法分析探讨净光合速率与主要生理、生态因子间的关系.结果表明:(1)苎麻叶片的净光合速率(Pn)日变化曲线呈现双峰型,2个光合峰高度接近,其净光合速率具有典型的午休"现象;蒸腾速率(Tr)日变化曲线呈现单峰型,其走势与气孔导度(Gs)日变化一致.(2)苎麻叶片光合作用的光饱和点(LSP)为1 568.5μmol?m-2?s-1,光补偿点(LCP)为54.18μmol?m-2?s-1,表观量子效率(AQY)为0.025 8 mol?mol-1;而其CO2补偿点(CCP)、饱和点(CSP)和羧化效率(CE)分别为49.25、1 746.9μmol?mol-1和0.045;因此,苎麻属于喜光性阳生植物,且对强光有一定的耐受能力.(3)苎麻叶片Pn日变化的主要限制因子是胞间CO2浓度(Ci),主要决定生理因子是气孔导度(Gs).     

不同术式的经内镜下行乳头括约肌切开术（EST）对肠胆反流的影响

目的：目前认为,十二指肠胆道反流是引起胆道反复感染,进而导致胆道结石再发和胆道狭窄的原因之一。近年来应用以内镜下逆行胆胰管造影术（endoscopicretrogradecholangiopancreatography,ERCP）为基础的微创治疗胆总管结束的技术开展颇为广泛。它主要包括ERCP、Oddi括约肌切开术（endoscopicsphincterotomy,EST）、十二指肠乳头球囊扩张术（endoscopicpapillarybal—Iondilation,EPBD）、胆管结石碎石取石术、胆总管支架植入术和鼻胆管引流术六大技术。本文主要研究了采用不同术式的EST,即EST中切口和EST小切口＋EPBD术,在术后早期对患者十二指肠胆道反流的影响。方法：63例胆总管结石患者,男30例,女33例,予行经内镜下逆行的胆胰管造影（ERCP）后分别采用不同术式EST,术后安放胆总管引流管。术后l周留取胆汁采用口服核素和测定胆汁中的胃蛋白酶I、II的浓度,对十二指肠胆道反流进行定量和定性的测定。结果：EST中切口术组、EST小切口＋球囊扩张（EPBD）组分别与无EST组相比,年龄和性别无统计学意义（P=0．07,P=0．416）。行EST中切开和小切开＋球囊扩张患者胆汁中的锝计数明显高于无EST组,且这两组不同术式的患者锝计数存在显著的统计学差异（P〈0．05）。行EST中切口者、EST小切口＋球囊扩张术者胆汁中的PGII质量浓度明显低于无EST组（P〈0．05）,但是EST中切口者和EST小切口＋球囊扩张术后两组间胆汁中PGII的质量浓度无统计学差异。结论：行EST中切口取胆总管结石的患者在手术早期较易发生十二指肠胆道的反流。因此,建议对于胆总管结石患者尽量选择行EST小切口＋球裳扩张术（EPBD）的手术方式。     

玉米叶片生长部位渗透调节和生长的生物物理参数变化

玉米叶片生长部位随着水分胁迫加剧ψ_w降低、LER减慢。LER从最大到零,快速干旱处理的ψw从-0.55降至-0.85 MPa;缓慢干旱处理ψ_w从-0.88降至-1.13 MPa。在任何一种LER下,缓慢干旱处理的ψ_s比快速干旱处理更低,生长停止时,前者为-1.57 MPa,而后者为-1.30MPa。缓慢干旱叶片尽管在更低ψ_w下,仍能维持一定膨压,保持一定的生长速率。经历长时间水分胁迫会改变细胞延伸生长的生物物理参数,增大临界膨压(0.08～0.09 MPa)。这是水分胁迫植株,在一定ψ_p下生长速率减慢的原因。     

The co-distribution of Plasmodium falciparum and hookworm among African schoolchildren

Background

On the island of Bioko (Equatorial Guinea), insecticide-treated nets (ITNs) have been the main tool used to control malaria over the last 13 years. In 2004, started an indoor residual spraying (IRS) campaign to control malaria. The purpose of this study is to asses the impact of the two control strategies on the island of Bioko (Equatorial Guinea), with regards to Plasmodium infection and anaemia in the children under five years of age.

Methods

Two transversal studies, the first one prior to the start of the IRS campaign and the second one year later. Sampling was carried out by stratified clusters. Malaria infection was measured by means of thick and thin film, and the packed cell volume (PCV) percentage. Data related to ITN use and information regarding IRS were collected. The Pearson's chi-square and logistic regression statistical tests were used to calculate odds ratios (OR)

Results

In the first survey, 168 children were sampled and 433 children in the second one. The prevalence of infection was 40% in 2004, and significantly lower at 21.7% in 2005. PCV was 41% and 39%, respectively. 58% of the children surveyed in 2004 and 44.3% in 2005 had slept under an ITN. 78% of the dwellings studied in 2005 had been sprayed. In the 2005 survey, sleeping without a mosquito net meant a risk of infection 3 times greater than sleeping protected with a net hanged correctly and with no holes (p < 0.05).

Conclusion

IRS and ITNs have proven to be effective control strategies on the island of Bioko. The choice of one or other strategy is, above all, a question of operational feasibility and availability of local resources.     

Tomato yellow leaf curl viruses: ménage à trois between the virus complex,the plant and the whitefly vector

Tomato yellow leaf curl disease (TYLCD) is one of the most devastating viral diseases affecting tomato crops in tropical, subtropical and temperate regions of the world. Here, we focus on the interactions through recombination between the different begomovirus species causing TYLCD, provide an overview of the interactions with the cellular genes involved in viral replication, and highlight recent progress on the relationships between these viruses and their vector, the whitefly Bemisia tabaci. Taxonomy: The tomato yellow leaf curl virus‐like viruses (TYLCVs) are a complex of begomoviruses (family Geminiviridae, genus Begomovirus) including 10 accepted species: Tomato yellow leaf curl Axarquia virus (TYLCAxV), Tomato yellow leaf curl China virus (TYLCCNV), Tomato yellow leaf curl Guangdong virus (TYLCGuV), Tomato yellow leaf curl Indonesia virus (TYLCIDV), Tomato yellow leaf curl Kanchanaburi virus (TYLVKaV), Tomato yellow leaf curl Malaga virus (TYLCMalV), Tomato yellow leaf curl Mali virus (TYLCMLV), Tomato yellow leaf curl Sardinia virus (TYLCSV), Tomato yellow leaf curl Thailand virus (TYLCTHV), Tomato yellow leaf curl Vietnam virus (TYLCVNV) and Tomato yellow leaf curl virus(TYLCV). We follow the species demarcation criteria of the International Committee on Taxonomy of Viruses (ICTV), the most important of which is an 89% nucleotide identity threshold between full‐length DNA‐A component nucleotide sequences for begomovirus species. Strains of a species are defined by a 93% nucleotide identity threshold. Host range: The primary host of TYLCVs is tomato (Solanum lycopersicum), but they can also naturally infect other crops [common bean (Phaseolus vulgaris), sweet pepper (Capsicum annuum), chilli pepper (C. chinense) and tobacco (Nicotiana tabacum)], a number of ornamentals [petunia (Petunia×hybrida) and lisianthus (Eustoma grandiflora)], as well as common weeds (Solanum nigrum and Datura stramonium). TYLCVs also infect the experimental host Nicotiana benthamiana. Disease symptoms: Infected tomato plants are stunted or dwarfed, with leaflets rolled upwards and inwards; young leaves are slightly chlorotic; in recently infected plants, fruits might not be produced or, if produced, are small and unmarketable. In common bean, some TYLCVs produce the bean leaf crumple disease, with thickening, epinasty, crumpling, blade reduction and upward curling of leaves, as well as abnormal shoot proliferation and internode reduction; the very small leaves result in a bushy appearance.     

Circle of Willis variation in a complex stroke presentation: a case report

Background  

The impact of circle of Willis anatomical variation upon the presentation of stroke is probably underrecognised.     

利用重组自交系群体对黄瓜侧枝相关性状进行QTL定位分析

侧枝与黄瓜(Cucumis sativus)产量有密切关系. 本实验利用侧枝长势较弱、萌发较早的华北类型品系S94和侧枝长势较强、萌发较晚的欧洲类型品系S06构建的224个F6:7家系进行黄瓜侧枝相关性状的研究. 利用已构建的重组自交系群体遗传图谱, 使用软件WinQTLCart 2.5进行复合区间定位. 在2006年秋和2007年春两季, 共检测到4个侧枝相关性状(侧枝均长LBAL、侧枝总长LBTL、侧枝数目LBN和第一侧枝节位FLBN)的36个QTL, 单个QTL的贡献率在3.1%(lbtl2.1, 春季)~32.3%(lbn2.3, 春季)之间. 结果显示, 4个不同性状的11个QTL (lbal1.1, lbtl1.1, lbn1.2, flbn1.2等)在两季中都聚集在第1连锁群e23m18d~ME23EM6c之间(7.4 cM), 并且在第2连锁群的S94A1~ME4SA4a之间(13.9 cM)也检测到了4个不同性状的15个QTL (lbal2.1, lbtl2.1, lbn2.1和flbn2.1等). 两季共有21个QTL贡献率超过10%, 其中lbn2.3的贡献率(春季32.3%, LOD=18.4)为最大, lbtl1.3(秋季26.2%, LOD=17.4; 春季26.9%, LOD=17.9)在两季的位置和贡献率都稳定. 这些基因座为将来进行QTL精细定位提供了参考, 同时利用其紧密连锁(<10 cM)的特异标记(CMBR40, F, CS30, S94A1, CSWTA11B)可进行黄瓜侧枝性状的分子标记辅助育种.     

Genetic Diversity of Global Aromatic Rice Varieties

Genetic diversity of 434 rice accessions collected from 16 countries, including 345 fragrance rice varieties and 89 non fragrance rice varieties, have been analyzed. A total of 573 alleles were detected by using 77 simple sequence repeats (SSR) primer pairs covering all rice 12 chromosomes. The value of allelic polymorphism information content (PIC) ranged from 0090 to 0845, with an average of 0516 per locus; Gene diversity (GD) varied from 0091 to 0859, with an average of 0573; The mean value of major allele frequencies (MAF) was 0540, covering from 0251 to 0953. In addition, 434 rice accessions are divided into three sub populations by cluster and population structure analysis, and FST between sub populations showed a mean of -0116, ranging from -0623 to 0494; The score of genetic distance calculated by Nei′s method appeared from 0207 to 0355. Major allele frequencies within each sub population distributed from 0408 to 0746, and gene diversity level from 0354 to 0699, while PIC from 0320 to 0658. Sequencing 6 mitochondrion genes in 18 rice varieties exhibited no different in 5 genes, whereas Mit4 contains a 3 SNPs in the gene body, which acts as an important marker to understanding the relationship between Indica/Japonica differentiation and the evolution of fragrant gene. Finally, genetic diversity and mitochondrion gene sequencing would help to know about the origin of fragrant resource and benefit rice breeding.     

Toll‐like receptor 9 protects non‐immune cells from stress by modulating mitochondrial ATP synthesis through the inhibition of SERCA2

Toll‐like receptor 9 (TLR9) has a key role in the recognition of pathogen DNA in the context of infection and cellular DNA that is released from damaged cells. Pro‐inflammatory TLR9 signalling pathways in immune cells have been well investigated, but we have recently discovered an alternative pathway in which TLR9 temporarily reduces energy substrates to induce cellular protection from stress in cardiomyocytes and neurons. However, the mechanism by which TLR9 stimulation reduces energy substrates remained unknown. Here, we identify the calcium‐transporting ATPase, SERCA2 (also known as Atp2a2), as a key molecule for the alternative TLR9 signalling pathway. TLR9 stimulation reduces SERCA2 activity, modulating Ca²⁺ handling between the SR/ER and mitochondria, which leads to a decrease in mitochondrial ATP levels and the activation of cellular protective machinery. These findings reveal how distinct innate responses can be elicited in immune and non‐immune cells—including cardiomyocytes—using the same ligand‐receptor system.