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The establishment, reproduction, dispersal, and distribution of alien plants are affected by various factors during the transition from being newly introduced in a habitat to being invasive. In the agro-pastoral ecotone of northern China, comprising farmlands and natural grasslands, the biological characteristics of alien plant species were the key intrinsic factors (propagation characteristics and competitive ability), followed by such extrinsic factors as human interference and environmental heterogeneity. Among biological characteristics, the life form may be an important and useful indicator of the invasive ability of a species, and the risk of invasion is greater from alien species that are poisonous, inedible, and have traits that facilitate wide dispersal. Farmlands may serve as initial shelters for alien species, from which they spread into neighbouring habitats, whereas natural grassland may act as a barrier to plant invasions. Management practices detrimental to grasslands, including overgrazing, reclamation, and road construction, often facilitate the invasions; therefore, counter measures such as reseeding and a ban on grazing need special attention. Environmental factors including precipitation, nutrients, prevailing winds, fires, and topography may be other factors that promote or block the process of invasion. In studying ways of preventing or controlling such invasions, alien plants with short life cycle, prolific seed production, and strong competitiveness, deserve particular attention and so do human activities that may damage the environment and fragile habitats.

Using the published literature and records, this study investigated the historical introduction, geographical distribution, and biological characteristics of 404 alien plants in 32 provinces (including municipalities) in China. The results showed that three fifths of the alien plants was introduced for intentional purposes, and the introduction of alien plants increased with time from 139 BC to the current time, especially during historical events that played an important part in the process of introduction. The geographical distribution of alien plant species tended to decrease from the south and the east to the north and the west. Annual average precipitation (Y = 7.51X + 7.05, R2 = 0.67) and temperature (Y = 0.07X + 41.54, R2 = 0.67) had a linear relationship with alien plant introduction throughout China. Furthermore, population density and economic conditions also affected and promoted plant invasions in China. The life forms were well adapted to regional precipitation and temperature, but different life forms of alien plants were not consistent with the distribution tendency based on the quantity of alien plants. There was a higher percentage of annual and biennial plants in the northern provinces (e.g. 66.7 and 15.7% in Inner Mongolia), whereas there were more perennial and woody plant species in the southern provinces (e.g. 37.0 and 21.2% in Hainan). Family characteristics could not accurately predict plant invasions; however, predictions based on genera were acceptable. In addition, the origin of alien plants can also predict the distribution and potential risk of invasions. Thus, our study investigated the factors affecting plant invasions in order to provide information on the prevention and control of alien plants.

Objective To investigate the effect and safety of bilirubin serum adsorption (BSA) in the treatment of patients with chronic severe hepatitis B. MethodsA prospective study was performed for 40 patients with chronic severe hepatitis B［prothrombin activity (PTA)＞25%］ who were hospitalized in The Second Xiangya Hospital of Central South University from January 1, 2014 to December 31, 2015, and all the patients were given BSA. The results of routine blood test ［white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin (Hb), and platelet (PLT) count］, coagulation function ［prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen (Fib)］, liver function ［total bilirubin (TBil), direct bilirubin (DBil), total bile acid (TBA), albumin (Alb), and globulin (Glb)］, and electrolytes (K+, Na+, Cl-, and Ca2+) were collected before treatment and at 1 week after treatment. Blood pressure, breath, heart rate, and oxygen saturation were observed and recorded before, during, and after treatment, and the presence or absence of symptoms such as fear of cold, pyrexia, dizziness, chest distress, and abdominal pain was observed. The t-test was used for comparison of continuous data between groups. ResultsAll the patients had good tolerance of the treatment, and clinical symptoms were improved after treatment. TBil, DBil, and TBA showed significant reductions, Alb, Glb, and Fib showed slight reductions, and PT and APTT were significantly prolonged (t=21.254, 22.395, 7.821, 6.986, 7.580, 9.852, 10.705, and 5.528, all P＜0.001). After treatment, Ca2+ level was significantly reduced and WBC count increased significantly (t=6.924 and 9.852, both P＜0.001). At the 1-week follow-up, Alb, Glb, Fib, PT, APTT, Ca2+ level, and WBC count almost returned to the same levels before treatment, and TBil, DBil, and TBA showed varying degrees of increases compared with the values after treatment, but remained lower than the values before treatment. Of all the 40 patients, 12(30%) experienced adverse events, among whom 3(7.5%) experienced fear of cold (or chills), 3(7.5%) experienced reduced blood pressure, 2(5.0%) experienced reduced heart rate, 1(2.5%) experienced nausea and vomit, 1(2.5%) experienced abdominal pain, and 1(2.5%) experienced cold sweat. ConclusionBSA therapy is safe and effective in the treatment of patients with chronic severe hepatitis B and PTA＞25% and has transient effects on patients′ coagulation function, serum calcium, and WBC count.

ObjectiveTo explore the methods for prevention and treatment of endotoxemia and multiple organ failure in patients with severe hepatitis. MethodsA total of 61 patients with severe hepatitis and toxic enteroparalysis were randomly assigned to three groups. The first group was treated with plasmapheresis, the second group with plasmapheresis and colon dialysis, and the third group with plasmapheresis, colon dialysis, and oral probiotics. Analyses were performed on the clinical symptoms and physical signs, hepatic function, endotoxin level, and clinical outcome in each group. Comparison of continuous data between groups was performed by analysis of variance, and further pairwise comparison by SNK test; comparison of categorical data between two groups was performed by chi-square test. ResultsThe liver function improved in all groups after treatment. The endotoxin level was significantly lower in the third group than in the other two groups (P＜005). The symptom improvement rates in the three groups were 35.3%, 64.7%, and 81.5%, respectively; the recurrence rates were 833%, 727%, and 364%, respectively; the clinical remission rates were 5.9%, 17.6%, and 48.1%, respectively, and the third group had a significantly higher rate than the first group (χ2=8.59, P＜0.05). ConclusionA combination of plasmapheresis, colon dialysis, and oral probiotics can effectively improve the prognosis of patients with severe hepatitis and toxic enteroparalysis, and can help prevent and treat multiple organ failure in such patients.

Austenite grain size plays an important role for quenched and tempered A517 GrQ rack steel. In order to investigate the austenite grain growth behavior, in-situ austenizing experiments were conducted at different temperatures with varied holding time. Austenite grain growth, and subsequent bainite and martensite transformation were observed by a confocal laser scanning microscope (CLSM). The average austenite grain size increased rapidly from 32.7 μm to 137.9 μm with increasing temperature from 1100 °C to 1250 °C, and abnormal grain growth occurred at 1250 °C for 15 min. While holding from 5 min to 20 min at 1200 °C, the grain size grew gradually from 70.2 μm to 84.8 μm. The grain size distributions under different conditions all obey lognormal function. After austenizing, the rate of subsequent cooling has an significant impact on transformation process. The transformation duration time decreased from over 142 s to 11 s with increasing cooling rate at 1 °C/s and 5 °C/s, which could be corresponding to bainite and martensite transformation respectively.