Structural Optimization,Fungicidal Activities Evaluation,DFT Study and Structure-Activity Relationship of Dopamine Derivatives with Benzothiazole Fragment from Polyrhachis dives

In our previous work, two dopamine derivatives with benzothiazole fragment were isolated and identified from Polyrhachis dives (P. dives). Based on their characteristic structure, we used them as lead compound to carry out structural optimization and subsequent fungicidal evaluation. Here 20 dopamine derivatives with benzothiazole fragment were designed and synthesized by a facile method, and their structures were characterized by ¹H-NMR, ¹³CNMR and HMRS. In bioassays, most of the title compounds possess potential fungicidal activities against Altenaia alternala (A. alternala) and Botrytis cinerea (B. cinerea). Especially, (E)-N-(2-(benzo[d]thiazol-6-yl)ethyl)-3-(p-tolyl)acrylamide and (E)-N-(2-(benzo[d]thiazol-6-yl)ethyl)-3-(4-(trifluoromethyl)phenyl)acrylamide displayed 29.3 mg/L and 10.7 mg/L EC₅₀ value against A. alternala, respectively, which possessed equivalent fungicidal activities level to hymexazol.     

Terpenoids from Euphorbia helioscopia and Their Cytotoxic Activities against H1975 Cells

Three previously undescribed diterpenoids, helioscopnoids A–C, and eight known compounds were isolated from the whole plants of Euphorbia helioscopia. Their structures were established by extensive analysis of spectra and data comparison with previous literatures. Among them, compound 4 was identified as 24,24-dimethoxy-25,26,27-trinoreuphan-3β-ol with revised configurations of C-13, C-14, and C-17 (13R*, 14R*, 17R*). Cytotoxicity assays revealed that all compounds exhibited varying levels of cytotoxicity against H1975 cells, with compound 9 displaying the most potent activity, as indicated by cell viability rates of 18.13 % and 20.76 % at concentrations of 20 μM and 5 μM, respectively. This study expands the understanding of E. helioscopia terpenoids’ structural diversity and biological activities, contributing to the exploration of potential therapeutic applications.     

Land use induced changes of organic carbon storage in soils of China

Using the data compiled from China's second national soil survey and an improved method of soil carbon bulk density, we have estimated the changes of soil organic carbon due to land use, and compared the spatial distribution and storage of soil organic carbon (SOC) in cultivated soils and noncultivated soils in China. The results reveal that ～ 57% of the cultivated soil subgroups ( ～ 31% of the total soil surface) have experienced a significant carbon loss, ranging from 40% to 10% relative to their noncultivated counterparts. The most significant carbon loss is observed for the non‐irrigated soils (dry farmland) within a semiarid/semihumid belt from northeastern to southwestern China, with the maximum loss occurring in northeast China. On the contrary, SOC has increased in the paddy and irrigated soils in northwest China. No significant change is observed for forest soils in southern China, grassland and desert soils in northwest China, as well as irrigated soils in eastern China. The SOC storage and density under noncultivated conditions in China are estimated to ～ 77.4 Pg (10¹⁵ g) and ～ 8.8 kg C m^?2, respectively, compared to a SOC storage of ～ 70.3 Pg and an average SOC density of ～ 8.0 kg C m^?2 under the present‐day conditions. This suggests a loss of ～ 7.1 Pg SOC and a decrease of ～ 0.8 kg C m^?2 SOC density due to increasing human activities, in which the loss in organic horizons has contributed to ～ 77%. This total loss of SOC in China induced by land use represents ～ 9.5% of the world's SOC decrease. This amount is equivalent to ～ 3.5 ppmv of the atmospheric CO₂ increase. Since ～ 78% of the currently cultivated soils in China have been degraded to a low/medium productivities and are responsible for most of the SOC loss, an improved land management, such as the development of irrigated and paddy land uses, would have a considerable potential in restoring the SOC storage. Assuming a restoration of ～ 50% of the lost SOC during the next 20–50 years, the soils in China would absorb ～ 3.5 Pg of carbon from the atmosphere.     

Gathered fruits and cultivated plants at Bercy (Paris), a Neolithic village in a fluvial context

Recent rescue excavations at Bercy (Paris), a site on the alluvial plain of the Seine valley, yielded plant remains which are associated with the recent occupation phase dating from the middle Neolithic II (Chasséen), when a village was established on the former channel of the river Seine. Various contexts (the channel, the flat lower part of the bank, and several archaeological features) have been studied and 84 taxa have been identified. Cultivated plants are represented by Triticum aestivum/durum, T. dicoccum, T. monococcum and Hordeum vulgare. Among the wild plants with potentially edible fruits or seeds, only very few satisfy the various criteria for association with human activities: Corylus avellana, Vitis sylvestris, Cornus sanguinea, Quercus sp. and Prunus spinosa of which carbonized fruits were also present, were found in archaeological features and were very abundant. Though not found in archaeological features, we consider that Crataegus monogyna (carbonized and well represented) and Rubus spp. (especially abundant) were not deposited there naturally and had also been intentionally collected. Finally, it is suggested that the allochthonous (varied) origin of these taxa is the reason why there are no concentrations of their fruits in the channel. The exploitation of wild seeds and fruits appears to have been very selective. All other wild taxa can be attributed to natural deposition.     

Effect of dietary caffeine and zinc on the activity of antioxidant enzymes,zinc, and copper concentration of the heart and liver in fast-growing rats

The purpose of this study was to determine the relationship between concentrations of Zn and Cu and the activities of superoxide dismutase and glutathione peroxidase in the heart and liver of young rat pups whose dams were fed a diet supplemented with caffeine and/or Zn. Four groups of dams with their newborn pups were fed one of the following diets for 22 d: 20% protein basal diet; the basal diet supplemented with caffeine (2 mg/100 body wt); the basal diet supplemented with Zn (300 mg/kg diet); or the basal diet supplemented with caffeine plus Zn. The Cu levels in the livers of the pups were decreased by maternal intake of the caffeine and Zn diet. The maternal intake of the caffeine diet increased Mn-superoxide dismutase (MnSOD) activity and Cu, Zn-superoxide dismutase (CUZnSOD) in the heart of the pups. On the other hand, the activity of Cu,ZnSOD was significantly reduced in the liver of pups whose dams consumed a caffeine, Zn, or caffeine plus Zn diet. Cu, ZnSOD activity in the liver of the pups seems to be correlated with Cu levels in the tissue. Selenium-dependent glutathione peroxidase (GSH-Px) activities in the heart and liver showed no difference among the groups. The effect of dietary caffeine and/or Zn on the activity of antioxidant enzymes in the heart and liver were different in young rats. The activities of these enzymes in the heart were lower than in the liver of 22-d-old rats. Our experiments indicate that the heart has limited defenses against the toxic effects of peroxides when compared to the liver.     

Factors related to diversity of decomposer fungi in tropical forests

Recent studies suggest that host-preferences are common among certain groups of tropical fungal decomposers but rare in others, and sometimes occur where we least expect them. Host preferences among microfungi and ascomycetes that decompose leaf litter are common but usually involve differences in relative frequencies more than presence/absence, so their diversity may be loosely correlated with species richness of host trees. Strong host-specificity appears to be rare among wood decomposer fungi, whereas characteristics of their substrata and habitat are very important for this group. Anthropogenic disturbance predisposed a tropical forest to subsequent hurricane damage, and the resulting direct and indirect effects on host diversity and habitat heterogeneity were reflected in the decomposer fungal community more than sixty years after the original disturbance. While species richness of dictyostelid slime molds and functional diversity of their bacterial prey increased with disturbance, the more diverse microfungi and ascomycetes were apparently negatively affected by disturbance.     

革胡子鲇上颌须离体标本味觉反应的测定

本实验采用革胡子鲇离体上颌须－传入神经标本,记录传入神经电活动,测定了须部味蕾对动物组织浸提液、氨基酸、酸盐化合物等多种化学刺激的反应。发现某些物质有较强的刺激作用。另外,机械刺激也引起较强的反应。分析传入神经单纤维的记录结果,可将化学刺激引起的味觉反应分为３种单元类型：（１）对精氨酸特别敏感;（２）对柠檬酸和氯化胺有较强的反应;（３）对多种刺激都有一定的反应。实验表明,革胡子鲇的须部味蕾可能是一     

Prevalence and upper limit of cardiac hypertrophy in professional cyclists

The term athlete's heart refers to an increased left ventricular mass. Few studies have assessed the prevalence and normal upper limit of cardiac hypertrophy in highly trained cyclists and this was the aim of this study. A group of 40 professional road cyclists [mean age 26 (SD 3) years] who had participated in European competitions for 3–10 years, were evaluated at the beginning of the 1992–93 season. Evaluation included a clinical history and physical examination, one and two-dimensional echocardiography, 12-lead resting electrocardiogram and a graded exercise test. Determination of the left ventricular mass index (LVMI) was performed using Devereux's formula with correction for the body surface area. Systolic and diastolic blood pressure were measured at rest and at peak exercise. Of the group 23 cyclists (58%) presented a LVMI greater than 130 g · m^–2, 21 cyclists presented a diastolic ventricular thickness equal to or greater than 13 mm, with a superior limit of 19 mm; 3 cyclists presented asymmetrical septum hypertrophy; and the relationship between posterior wall and left ventricular diastolic radius was equal to or greater than 0.45 in 14 cases (35%). Electrocardiographic abnormalities of ST-T segment were seen in only 1 subject. No correlation was found between the degree of ventricular hypertrophy and arterial blood pressure. We concluded that these professional cyclists showed a high prevalence of cardiac hypertrophy (58%). The distribution of this hypertrophy was concentric in 20/33 and asymmetric in 3/23 of the subjects with left ventricular hypertrophy. The electrocardiograms were normal in 98% of the subjects.     

Feedback inhibition of sodium uptake in K+-depolarized toad urinary bladders

Ouabain-blocked toad urinary bladders were maintained in Na⁺-free mucosal solutions, and a depolarizing solution of high K⁺ activity containing only 5 mM Na⁺ on the serosal side. Exposure to mucosal sodium (20 mM activity) evoked a transient amiloride-blockable inward current, which decayed to near zero within one hour. The apical sodium conductance increased in the initial phase of the current decay and decreased in the second phase. The conductance decrease required Ca²⁺ to be present on the serosal side and was more rapid when the mucosal Na⁺ activity was higher. At 20 mM mucosal Na⁺ and 3 mM serosal Ca²⁺ the initial (maximal) rate of inhibition amounted to 20% in 10 min. The conductance decrease could be accelerated by raising the serosal Ca²⁺ activity to 10 mM. The inhibition reversed on lowering the serosal Ca²⁺ to 3 μM and, in addition, the mucosal Na⁺ to zero. Exposure of the mucosal surface to the ionophore nystatin abolished the Ca²⁺ sensitivity of the transcellular conductance, showing that the Ca²⁺-sensitive conductance resides in the apical membrane. The data imply that in the K⁺-depolarized epithelia, cellular Ca²⁺, taken up from the serosal medium by means of a Na⁺-Ca²⁺ antiport, cause feedback inhibition by blockage of apical Na⁺ channels. However, the rate of inhibition is small, such that this regulatory mechanism will have little effect at 1 mM serosal Ca²⁺ and less than 20 mM cellular Na⁺.     

Photosynthetic carbon assimilation in the blue-green alga Coccochloris peniocystis

Abstract. Cells of the blue-green alga Coccochloris peniocystis , grown at air levels of CO₂, were exposed to [^l4C]bicarbonate in the light for periods of 0.5 to 2.0 s followed by exposure to unlabelled bicarbonate for longer periods of time in the light. The kinetics of tracer movement during these pulse-chase experiments demonstrate that the principal mechanism of CO₂ fixation in this alga is the C₃-pathway although an appreciable amount of the C₄ acid aspartate is found as one of the initial products of photosynthesis. Degradation of the labelled aspartate revealed that after 20 s of illumination, over 95% of the radioactivity was located in the β-carboxyl of this C₄ acid. This alga possesses little, if any, capacity for either the enzymatic decarboxylation of C₄ acids or the regeneration of phosphoenolpyruvate (PEP) from pyruvate mediated by the enzyme pyruvate, P_i dikinase. These data further demonstrate the lack of a functional C₄-pathway in this alga.