Wood structure and properties of clonal plantlets and seedlings of Pinus radiata

The ontogeny of vascular cambium and the wood formation in the 8 month-old Pinus radiata have been examined. The results showed that the procambium develops from the subapical meristem parenchyma, which is converted to pro cambial cells by periclinal division about 0.5 mm from the shoot tip. The interfascicular cambium originates from the interfascicular parenchyma, which is also derived from the subapical meristem. Transverse sections show that the interfascicular parenchyma convert to interfascicular cambial cells requires activation by the fascicular cambium. The vascular cambium was established by the fascicular cambium connecting with the interfascicular cambium. Compression wood formation is related to the plantlet's response to stress. The magnitude and distribution of compression wood is related to whether the stem is free-growing, staked vertically, or tied to an inclined stake, the three situations generating 27%, 14% and 49% compression wood as assessed by image analysis of thin sections. Stiffness, density, tracheid length, cell numbers/mm2, and percent cell wall area were tested for plantlets of clones 8 and 31 grown under three treatments. Compared to the free grown plantlets, the angled plantlets were shorter, thinner, contained more compression wood with thicker cell walls and more cells/mm2, and had shorter denser tracheids to formed weaker wood. By contrast the tied plantlets were taller and thinner, having fewer cells/mm2 with each tracheid being longer and less dense (thinner cell walls), but of similar stiffness to the free grown ones. Compression wood was stiffer than opposite wood because of its higher density, and the angled plantlets were weaker than the free and tied plantlets due to their shorter tracheids. Stiffness is related to density in angled plantlets, and related to tracheid length in the free and tied plantlets. Tracheid length is negatively related to density, cells/mm2, and percent cell wall. Density is related to percent cell wall and cells/mm2, and the percent cell wall and cells/mm2 related each other. Stiffness, microfibril angle, density, and maximum crushing strength have been studied for 1 and 2 year-old seedlings from seedlots 10 and 28. The results indicated that stiffness increased and microfibril angle decreased from one year-old to two year-old material. A relationship between maximum crushing strength and density and a negative relationship between stiffness and microfibril angle existed in two years old plantlets. Stiffness and maximum crushing strength related each other in both one and two years old plantlets. Overall, this work proved to be a scoping trial. While the results could have been anticipated in general terms they do provide a useful description of very young wood. The extent of compression wood varied greatly between treatments, but even in the best case (tied) it takes up a significant proportion of the stem cross-section. However, the technical challenges, especially in the measurement of mechanical properties in such small samples remains a formidable challenge

Protein expression analysis of a high-demeclocycline producing strain of Streptomyces aureofaciens and the roles of CtcH and CtcJ in demeclocycline biosynthesis

Additional file 1: Online Resource 1. Primers used in this study

The role of the neutrophil Fcγ receptor I (CD64) index in diagnosing spontaneous bacterial peritonitis in cirrhotic patients

SummaryObjectiveTo investigate the role of the neutrophil Fcγ receptor I (CD64) index in the diagnosis of spontaneous bacterial peritonitis (SBP) in cirrhotic patients.MethodsA total of 123 cirrhotic patients with ascites who fulfilled the inclusion criteria were enrolled in this study. Ascites and blood samples were collected; the polymorphonuclear neutrophil (PMN) count, bacterial culture, and related laboratory tests were performed. The CD64 index was determined for each sample using flow cytometry.ResultsThe neutrophil CD64 index results were significantly higher in cirrhotic patients with SBP than in those without SBP (p<0.001). There was a positive correlation between the neutrophil CD64 index and the PMN count in ascites. In the receiver operating characteristic curve (ROC) analysis, the area under the curve (AUC) was 0.894 (95% confidence interval 0.823–0.964, p<0.001). The optimal cut-off value for the neutrophil CD64 index was 2.02. The sensitivity and specificity of the neutrophil CD64 index for cirrhotic patients with SBP were 80.49% and 93.90%, respectively. The elevated neutrophil CD64 index was down-regulated by antibiotic therapy (p=0.002).ConclusionsThe neutrophil CD64 index could be used as a sensitive and specific indicator for the diagnosis of SBP in cirrhotic patients with ascites and is also modulated by antibiotic therapy

Mutation Status and Immunohistochemical Correlation of KRAS, NRAS, and BRAF in 260 Chinese Colorectal and Gastric Cancers

KRAS, NRAS and BRAF are kinases involved in the RAS-RAF-MAPK signaling pathway and also potential tumor-driven genes. Patients with KRAS/NRAS/BRAF mutations are resistant to anti-EGFR monoclonal antibody therapy. The main purpose of this study is to investigate the mutation status and distribution of KRAS/NRAS/BRAF in Chinese colorectal and gastric cancers, and to explore the histopathological changes and related immunohistochemical marker changes caused by these mutations. The mutation status of KRAS (exons 2, codon 12/13), NRAS (exons 2/3/4, codon 12/13/59/61/117/146) and BRAF (exons 15, codon 600) were detected by amplification refractory mutation system polymerase chain reaction (ARMS-PCR) in 86 colon cancer, 140 rectal cancer and 34 gastric cancer tissues. Then, the frequencies and distribution of KRAS/NRAS/BRAF mutations were described in detail. Furthermore, the relationship between KRAS/NRAS/BRAF mutations and the features of histopathological and related immunohistochemical markers were analyzed. The results showed that KRAS/NRAS/BRAF mutation rates in colon cancer were 44.2, 1.2, and 3.5%; in rectal cancer were 37.1, 4.3, and 0.7%; in gastric cancer were none, none and 2.9%. The mutation rate of KRAS in female (48.8%) is significantly higher than that of male (27.8%), and the mutation rate increased with the higher degree of differentiation. Additionally, the mutation rate of BRAF detected by ARMS-PCR (1.77%) was significantly lower than that by immunohistochemistry (4.11%). It also showed that the KRAS/NRAS/BRAF mutation status had a certain relationship with the expression of some immunohistochemical markers. This study provides more data support for clinical research on KRAS/NRAS/BRAF mutation in CRCs or gastric cancers

Driving risk assessment and prevention strategies for autonomous vehicle in open-pits

Driving risk assessment and protection is the critical technology of unmanned transportation systems in open-pits. In order to warrant the safe operation of unmanned vehicles in open-pits, the Driving Security Model (DSM) based on the vehicle-road-cloud transportation system is established. Based on the multi-source information from the vehicle, roadside, and cloud platform, the DSM can assess the driving risk level of driverless vehicles and provide corresponding driving risk prevention strategies. The DSM comprises driving state awareness, driving risk assessment, and driving risk protection. In terms of driving risk assessment, the threshold of pre-collision time is corrected through the road slope ahead of the vehicle, and the minimum braking safety distance is modified by the information of road slope and vehicle load state. In the meantime, a comprehensive driving risk assessment strategy is proposed, which can quantify the real-time collision risk of autonomous vehicles in open-pits. Then, a collision risk protection system that considers different driving risks is then designed based on a finite state machine. A smooth braking control strategy is developed to meet the minimum safety distance. Finally, a digital twin simulation system that corresponds to the autonomous vehicle in an open-pit is built based on the PreScan and Matlab co-simulation technology and some simulation tests in the horizontal, uphill-downhill road and full load scenes are carried out. The simulation results show that the DSM’s comprehensive risk assessment strategy can evaluate suitable risk levels in advance and timely brake, which indicates that the introduction of road slope information can improve the driving safety of the vehicle up and downhill scenes. By introducing vehicle load information, the designed minimum safe braking distance index can detect potential collision risk in time. The DSM’s emergency braking control strategy can smoothly stop the vehicle before 10 m safe distance, which improves the stability of heavy-duty vehicles during emergency braking

Clinical presentation of hemophagocytic lymphohistiocytosis in adults is less typical than in children

OBJECTIVE: Hemophagocytic lymphohistiocytosis in adults is largely underdiagnosed. To improve the rate and accuracy of diagnosis in adults, the clinical and laboratory characteristics of hemophagocytic lymphohistiocytosis were analyzed in and compared between adults and children in a Chinese cohort. METHOD: Data from 50 hemophagocytic lymphohistiocytosis patients, including 34 adults and 16 children who fulfilled the 2004 hemophagocytic lymphohistiocytosis diagnostic criteria, were collected and analyzed. RESULTS: 1. Etiological factors: The proportion of Epstein-Barr virus infection was lower in adults compared with children, whereas fungal infection and natural killer/T cell lymphoma were more frequent in adults (