[Bryophyte diversity and microhabitat characteristics of bryophyte-dominated biological soil crusts development in water-wind erosion crisscross region of the northern Loess Plateau, China]. / é»„åœŸé«˜åŽŸåŒ—éƒ¨æ°´èš€é£Žèš€äº¤é”™åŒºè‹”è—“å¤šæ ·æ€§åŠè‹”è—“ç»“çš®å‘è‚²çš„å¾®ç”Ÿå¢ƒç‰¹å¾.

Microhabitat factors play an important role in regulating bryophyte species distribution and the development of bryophyte-dominated biological soil crusts (hereafter bryophyte crusts). We investigated the distribution and development of bryophytes in eight microhabitats in the water-wind erosion crisscross region of the Loess Pla-teau. We used the line intercept transects to explore and quantify the influencing pathways of microhabitat factors on bryophyte diversity and analyzed the influencing pathways of plant cover, slope aspect, and slope gradient by using structural equation model to quantify influencing coefficients. Our results showed that: 1) The Patrick, Shannon, Pielou, and Simpson indcies of bryophytes under plant canopy were 63.4%, 66.6%, 91.0%, and 68.3% lower than that without plant canopy, respectively, while the thickness, biomass, and chlorophyll content of bryophyte crusts were 0.5, 0.2, and 1.3 times higher than that without plant canopy, respectively. 2) The Patrick, Shannon, Pielou, and Simpson indexes of bryophytes on the north slope were 0.6, 0.9, 5.6, and 0.9 times higher than those on the south slope, while the thickness, biomass, and chlorophyll content of bryophyte crusts were 0.3, 0.3, and 0.6 times higher than those on the south slope, respectively. 3) As the slope increasing from 14° to 34°, the Patrick, Shannon, Pielou, and Simpson indexes of bryophyte were decreased by 59.8%, 84.1%, 57.3% and 68.0%, and the thickness, biomass, and chlorophyll content of bryophyte crusts were decreased by 15.2%, 25.0%, and 16.5%, respectively. 4) The importance of the three microhabitat factors on bryophyte diversity and the development of bryophyte crusts followed an order of plant canopy cover > slope aspect > slope gradient. The primary influencing pathway varied among the microhabitat factors. In conclusion, plant cover, slope aspect, and slope gradient significantly affected the distribution of bryophytes species and developmental level of bryophyte crusts through direct and indirect pathways. Therefore, full consideration should be given to microhabitat conditions when using bryophyte crusts to control desertification.

[Research progress on the bioweathering and controlling of stone cultural relics]. / çŸ³è´¨æ–‡ç‰©çš„ç”Ÿç‰©é£ŽåŒ–åŠå ¶é˜²æ²»ç ”ç©¶è¿›å±•.

The bioweathering of stone cultural relics is a ubiquitous problem. Weathering prevention is an escalating challenge under the increasing global climate and environmental changes. Here, the mechanisms of lichen-microorganism mediated weathering of stone materials and their relationships with climatic and environmental factors were reviewed. The biological protection of lichens and the evaluation of the efficacy of biocides in lichen-control were discussed. The potential research directions in this field were proposed. Research on lichen-rock interfaces suggested that biological weathe-ring could be mainly attributed to physical and chemical weathering which represented by mycelium penetration and calcium oxalate formation. Bioweathering of outdoor stone cultural relics is closely related with the whole ecosystem encompassing factors, such as stone matrix, surrounding environment, and climate factors. Lichens have both biological weathering and protection effects on stone heritage. For the restoration of bioweathered stone cultural relics, environmental conditions for pre-servation of stone cultural relics should be improved step by step. The related industry regulations and national standards for evaluating biological weathering and control efficiency should be established to promote the efficient development of scientific protection.

Enhancing inactivation rather than reducing activation of Nav1.7 channels by a clinically effective analgesic CNV1014802.

The Nav1.7 channel represents a promising target for pain relief. In the recent decades, a number of Nav1.7 channel inhibitors have been developed. According to the effects on channel kinetics, these inhibitors could be divided into two major classes: reducing activation or enhancing inactivation. To date, however, only several inhibitors have moved forward into phase 2 clinical trials and most of them display a less than ideal analgesic efficacy, thus intensifying the controversy regarding if an ideal candidate should preferentially affect the activation or inactivation state. In the present study, we investigated the action mechanisms of a recently clinically confirmed inhibitor CNV1014802 using both electrophysiology and site-directed mutagenesis. We found that CNV1014802 inhibited Nav1.7 channels through stabilizing a nonconductive inactivated state. When the cells expressing Nav1.7 channels were hold at 70 mV or 120 mV, the half maximal inhibitory concentration (IC50) values (with 95% confidence limits) were 1.77 (1.20-2.33) and 71.66 (46.85-96.48) µmol/L, respectively. This drug caused dramatic hyperpolarizing shift of channel inactivation but did not affect activation. Moreover, CNV1014802 accelerated the onset of inactivation and delayed the recovery from inactivation. Notably, application of CNV1014802 (30 µmol/L) could rescue the Nav1.7 mutations expressed in CHO cells that cause paroxysmal extreme pain disorder (PEPD), thereby restoring the impaired inactivation to those of the wild-type channel. Our study demonstrates that CNV1014802 enhances the inactivation but does not reduce the activation of Nav1.7 channels, suggesting that identifying inhibitors that preferentially affect inactivation is a promising approach for developing drugs targeting Nav1.7.

The sand-deposition impact of artificial gravel beds on the protection of the Mogao Grottoes.

Gravel beds can prevent sand-dust emission and weaken sand-dust flux. We used wind-tunnel experiments and field observations on artificial gravel beds above the Mogao Grottoes to quantify their impact. In the report, we identified a significant correlation between gravel roughness and its ability to trap wind-transported sand. The optimal combinations of gravel diameter and coverage were determined. The greatest roughness is achieved when small gravel coverage is 75%, medium 40% and large 45%. We found that initial wind speed and gravel coverage are the key factors controlling the amount of sand trapped by the gravel beds.