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Background Styrax , a vital raw material for shipbuilding, construction, perfumes, and drugs, represents the largest and most diverse genus in the Styracaceae. However, there is a relative scarcity of research on Styrax , particularly in evolution and genetics. Therefore, this study conducted comparative and evolutionary analyses of the chloroplast genomes of five rare Styrax species ( S. argentifolius , S. buchananii , S. chrysocarpus , S. finlaysonianus , and S. rhytidocarpus ). Results The results indicated that, despite high levels of conservation in chloroplast genome structure among these species, specific mutation hotspot regions exist, particularly involving the expansion and contraction of the IR region. Additionally, evidence of positive selection was detected in eight genes ( atpB , ccsA , ndhD , petA , rbcL , rpoC1 , ycf1 , and ycf2 ), which may be associated with adaptive evolution in response to environmental changes. Phylogenetic analysis revealed conflicts between trees constructed based on coding sequences and complete chloroplast genomes for several species, which were similar to previous phylogenetic studies. Conclusion This study underscores the importance of increasing sample sizes to enhance the accuracy of phylogenetic analyses and provides a new perspective on understanding the adaptive evolution of Styrax species. These findings are not only important for the conservation and sustainable use of Styrax , but also provide valuable insights for research in plant evolution and ecology within the genus.

Styrax japonicus is a medicinal and ornamental shrub belonging to the Styracaceae family. To explore the diversity and characteristics of the chloroplast genome of S. japonicus, we conducted sequencing and comparison of the chloroplast genomes of four naturally distributed S. japonicus. The results demonstrated that the four chloroplast genomes (157,914–157,962 bp) exhibited a typical quadripartite structure consisting of a large single copy (LSC) region, a small single copy (SSC) region, and a pair of reverse repeats (IRa and IRb), and the structure was highly conserved. DNA polymorphism analysis revealed that three coding genes (infA, psbK, and rpl33) and five intergene regions (petA-psbJ, trnC-petN, trnD-trnY, trnE-trnT, and trnY-trnE) were identified as mutation hotspots. These genetic fragments have the potential to be utilized as DNA barcodes for future identification purposes. When comparing the boundary genes, a small contraction was observed in the IR region of four S. japonicus. Selection pressure analysis indicated positive selection for ycf1 and ndhD. These findings collectively suggest the adaptive evolution of S. japonicus. The phylogenetic structure revealed conflicting relationships among several S. japonicus, indicating divergent evolutionary paths within this species. Our study concludes by uncovering the genetic traits of the chloroplast genome in the differentiation of S. japonicus variety, offering fresh perspectives on the evolutionary lineage of this species.

By using the geometric constraints on the control polygon of a Pythagorean hodograph (PH) quartic curve, we propose a sufficient condition for this curve to have monotone curvature and provide the detailed proof. Based on the results, we discuss the construction of spiral PH quartic curves between two given points and formulate the transition curve of a G2 contact between two circles with one circle inside another circle. In particular, we deduce an attainable range of the distance between the centers of the two circles and summarize the algorithm for implementation. Compared with the construction of a PH quintic curve, the complexity of the solution of the equation for obtaining the transition curves is reduced.

After analyzing the communication requirements of emergency rescue management-decisional support system in Whole-Treatment-Chain (WTC) and characteristics of wireless communication technologies, an integrated wireless communication platform based on 3G and satellites is proposed, with the dynamic switching method for different application scenarios. The implementation of this platform is presented afterwards followed by several experiments. Results analysis shows that this platform could maintain relatively stable commutation for both shelter hospital and ambulance but does not perform extremely well on medical train due to signal blocking. In a word, it enhances the application of management-decisional support system during emergency medical rescue.

This paper introduces a satellite /3G+ multi-link communication terminal based on medical rescue information system, which provides 3G wireless network and satellite communication services and integrates cellular phone, maritime satellite terminal, BeiDou user device and Iridium phone [1]. The new terminal could improve the communication adaptability and transmission efficiency for the emergency medical rescue information system even in hostile environmental conditions [2] (such as earthquake, flood, and war). Tests showed that: this terminal has the advantages of simple access, rapid switch, efficient transmission, it can also guarantee timely and effective interaction of all kinds of information, so as to ensure the time-effect treatment for emergency medical rescue system [3].

In this paper pre-cracked rock is used to study the strength affect by the coal rock internal fissures, through uniaxial compression tests to observe the different perspectives cracks on rock strength by using the precast specimens. The experimental results show that: the strength of specimens with crack angle increases, decreases and then increases, till reaches a maximum at 90°. Based on the force divided, destruction of different angles of prefabricated crack growth path can be divided into: shear failure, tensile failure and tensile shear composite damage.

Background： Dendritic cells are professional antigen-presenting cells found in an immature state in epithelia and interstitial space, where they capture antigens such as pathogens or damaged tissue. Matrix metallopeptidase 13 （MMP- 13）, a member of the collagenase subfamily, is involved in many different cellular processes and is expressed in murine bone marrow-derived dendritic cells （DCs）. The function of MMP-13 in DCs is not well understood. Here, we investigated the effect of MMP-13 on DC maturation, apoptosis, and phagocytosis. Methods： Bone marrow-derived dendritic cells were obtained fiom C57BL/6 mice. One short-interfering RNA specific for MMP- 13 was used to transfect DCs. MMP-13-silenced DCs and control DCs were prepared, and apoptosis was measured using real-time polymerase chain reaction and Western blotting. MMP-13-silenced DCs and control DCs were analyzed for surface expression of CD80 and CD86 and phagocytosis capability using flow cytometry. Results： Compared to the control DCs, MMP- 13-silenced DCs increased expression of anti-apoptosis-related genes, BAGl （control group vs. MMP-13-silenced group： 4.08 ± 0.60 vs. 6.11 ± 0.87, P = 0.008）, BCL-2 （control group vs. MMP-13-silenced group： 7.54 ± 0.76 vs. 9.54 ± 1.29, P = 0.036）, and TP73 （control group vs. MMP- 13-silenced group： 4.33 ± 0.29 vs. 5.60 ±0.32, P = 0.001 ） and decreased apoptosis-related genes, CASPI （control group vs. MMP- 13-silenced group： 3.79±0.67 vs. 2.54±0.39, P - 0.019）, LTBR （control group vs. MMP- 13-silenced group： 9.23 ±1.25 vs. 6.24 ± 1.15, P = 0.012）, and CASP4 （control group vs. MMP-13-silenced group： 2.07 ± 0.56 vs. 0.35 ±0.35, P = 0.002）. Protein levels confirmed the same expression pattern. MMP- 13-silenced groups decreased expression of CD86 on DCs; however, there was no statistical difference in CD80 surface expression. Furthermore, MMP-13-silenced groups exhibited weaker phagocytosis capability. Conclusion： These results indicate that MMP-13 inhibition dampens DC maturation, apoptosis, and phagocytosis.

Cyclic polymers have attracted more and more attentions in recent years because of their unique topological structures and characteristic properties in both solution and bulk state. There are relatively few reports on cyclic polymers, partly because of the more demanding synthetic procedures. In recent years, “click” reaction, especially Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC), has been widely utilized in the synthesis of cyclic polymer materials because of its high efficiency and low susceptibility to side reactions. In this review, we will focus on three aspects: (1) Constructions of monocyclic polymer using CuAAC “click” chemistry; (2) Formation of complex cyclic polymer topologies through CuAAC reactions; (3) Using CuAAC “click” reaction in the precise synthesis of molecularly defined macrocycles. We believe that the CuAAC click reaction is playing an important role in the design and synthesis of functional cyclic polymers.

The morphology of manganese sulfide formed during thin slab continuous casting process in low-carbon steel produced by compact strip production （CSP） technique was investigated. Using transmission electron microscopy analysis, it was seen that a majority of manganese sulfides precipitated at austenite grain boundaries, the morphologies of which were spherical or close to the spherical shape and the size of MnS precipitates ranged from 30 nm to 100 nm. A mathematical model of the manganese sulfide precipitation in this process was developed based on classical nucleation theory. Under the given conditions, the starting and finishing precipitation temperatures of MnS in the continuous casting thin slab of the studied low-carbon steel are 1 189 ℃ and 1 171 ℃, respectively, and the average diameter of MnS precipitates is about 48 nm within this precipitation temperature range. The influences of chemical components and thermo-mechanical processing conditions on the precipitation behavior of MnS in the same process were also discussed.

Equatorial spread-F （ESF） backscatter plumes are often observed in radar range-time-intensity （RTI） maps at low latitude. Except case studies, few statistical investigations on the onset locations of scintillation-producing ESF plumes at given sites have been conducted. In this study, a statistical analysis is carried out on onset locations of ESF backscatter plumes observed at a low-latitude location Sanya （18.4°N, 109.6°E; dip lat 12.8°N） during equinoctial months of 2013. By employing a tracing method to locate backscatter plumes, we estimate the onset longitudes of periodic plumes obtained from the Sanya VHF radar five-beam steering measurements. The results show that the inter-plume distances （in longitude） are mostly confined within 200–600 km, and the ESF plumes producing ionospheric scintillations over Sanya are almost exclusively generated at the longitudes of 94°–110°E. The results indicate the necessity to monitor ESF plume initial generation in the longitude region of 94°–110°E to better understand the day-to-day variability in the occurrence of ionospheric scintillations over Sanya.