Genetic Diversity and Linkage Disequilibrium in Chinese Bread Wheat (Triticum aestivum L.) Revealed by SSR Markers

Two hundred and fifty bread wheat lines, mainly Chinese mini core accessions, were assayed for polymorphism and linkage disequilibrium (LD) based on 512 whole-genome microsatellite loci representing a mean marker density of 5.1 cM. A total of 6,724 alleles ranging from 1 to 49 per locus were identified in all collections. The mean PIC value was 0.650, ranging from 0 to 0.965. Population structure and principal coordinate analysis revealed that landraces and modern varieties were two relatively independent genetic sub-groups. Landraces had a higher allelic diversity than modern varieties with respect to both genomes and chromosomes in terms of total number of alleles and allelic richness. 3,833 (57.0%) and 2,788 (41.5%) rare alleles with frequencies of <5% were found in the landrace and modern variety gene pools, respectively, indicating greater numbers of rare variants, or likely new alleles, in landraces. Analysis of molecular variance (AMOVA) showed that A genome had the largest genetic differentiation and D genome the lowest. In contrast to genetic diversity, modern varieties displayed a wider average LD decay across the whole genome for locus pairs with r2>0.05 (P<0.001) than the landraces. Mean LD decay distance for the landraces at the whole genome level was <5 cM, while a higher LD decay distance of 5–10 cM in modern varieties. LD decay distances were also somewhat different for each of the 21 chromosomes, being higher for most of the chromosomes in modern varieties (<5∼25 cM) compared to landraces (<5∼15 cM), presumably indicating the influences of domestication and breeding. This study facilitates predicting the marker density required to effectively associate genotypes with traits in Chinese wheat genetic resources

Mycobacterium vaccae as Adjuvant Therapy to Anti-Tuberculosis Chemotherapy in Never-Treated Tuberculosis Patients: A Meta-Analysis

OBJECTIVE: To evaluate the effectiveness and safety of heat-killed M. vaccae added to chemotherapy of never-treated tuberculosis (TB) patients. METHODS: The databases of Medline, Embase, Biosis, Cochrane Central Register of Controlled Trials, SCI, CBM, VIP and CNKI were searched. Randomized controlled trials (RCT) and Controlled clinical trials (CCT) comparing M. vaccae with or without a placebo-control injection as adjuvant therapy in the chemotherapy of never-treated TB patients were included. Two reviewers independently performed data extraction and quality assessment. Data were analyzed using RevMan 5.0 software by The Cochrane Collaboration. RESULTS: Fifty four studies were included. At the end of the follow-up period, Pooled RR (Risk Ratio) and its 95% CI of sputum smear conversion rate were 1.07 (1.04, 1.10) in TB patients without complications, 1.17 (0.92, 1.49) in TB patients with diabetes mellitus, 1.02 (0.94, 1.10) in TB patients with hepatitis B, and 1.46 (0.21, 10.06) in TB patients with pneumosilicosis. In elderly TB patients the RR was 1.22 (1.13, 1.32). Analysis of each time point during the follow-up period showed that M. vaccae could help to improve the removal of acid-fast bacilli from the sputum, and promote improvement of radiological focal lesions and cavity closure. Compared with the control group, the differences in levels of immunological indicators of Th1 such as IL-2 and TNF-α were not statistical significant (P = 0.65 and 0.31 respectively), and neither was that of IL-6 produced by Th2 (P = 0.52). An effect of M. vaccae of prevention of liver damage was found in TB patients with hepatitis B (RR 0.20 and 95% CI (0.12, 0.33). No systemic adverse events were reported. CONCLUSION: Added to chemotherapy, M. vaccae is helpful in the treatment of never-treated TB patients in terms of improving both sputum conversion and X-ray appearances

Experimental study on flow boiling of refrigerant R1233zd(E) in microchannels: Heat transfer

The paper reports accurate experimental data for flow boiling heat transfer of a new environmentally friendly refrigerant R1233zd(E) in parallel horizontal microchannels. The aluminium test section consists of two blocks and has 10 parallel channels with 1.0 mm in width, 1.5 mm in height and 440 mm in length. Five small thermocouple holes with diameter 0.6 mm and depth 20 mm were drilled at 10 locations along the channel on the two aluminium blocks, respectively. The local heat flux and channel surface temperature along the channel were obtained by using the inverse heat conduction method based on the temperatures in the test blocks accurately measured by 100 thermocouples. The local saturation temperatures were obtained by assuming the linear distribution of pressure in the two-phase flow region along the channel. Experiments were conducted in a wide range of working conditions. The refrigerant mass flow rate varied from 100 kg/m2 s to 450 kg/m2 s. The heating water mass flow rate varied from 600 ml/min to 1200 ml/min. The saturation pressure of refrigerant R1233zd(E) varied from 200 kPa to 350 kPa. The refrigerant liquid was maintained subcooled with 4.0 K at the inlet before entering the microchannels. The heat balance between the refrigerant and heating water sides agree well within 7.3%. The inverse results show effects of gravity, saturation pressure and heat flux on flow boiling heat transfer in microchannels. The work is of important value for understanding the fundamentals of flow boiling heat transfer in microchannels and development of accurate prediction method

Conjugation with 20kDa dextran decreases the autoxidation rate of bovine hemoglobin

Haemoglobin-based oxygen carrier (HBOC) is highly susceptible to autoxidation that renders a series of tissue and cellular toxicities. HBOC is prepared by chemical modification of haemoglobin (Hb), which typically increases the autoxidation rate of Hb. Thus, it is necessary to decrease the autoxidation of HBOC. In the present study, two dextran-bHb conjugates (dex20-bHb and dex40-bHb) were prepared by conjugation with 20kDa or 40kDa dextrans, where the thiol group of Cys-93() was reversibly protected. The autoxidation rate of bHb was decreased by conjugation with 20kDa dextran and maintained by conjugation with 40kDa dextran. In order to understand the low autoxidation rate of dex20-bHb, the effects of aldehyde modification and dextran on the autoxidation rate of dex20-bHb were investigated. The high oxygen affinity, high tetramer stability and dextran itself were found to decrease the autoxidation rate of dex20-bHb. The conjugated dextran had a predominant effect on decreasing the autoxidation rate of bHb, which was particularly promising for the potential development of safe HBOCs. Conjugation with dextran is of general significance to decrease the oxidation process of the heme-containing proteins, such as Hb and myoglobin