Ecological Investigation and Ecological Security Assessment of Xizhijiang River Basin in Huizhou City of Guangdong Province

In addition to such ecological problems as the pollution of the water system,the unreasonable structure of the upstream Basin and the insufficient water conservation forests,the Xizhi River Basin also faces human decision-making problems such as imperfect ecological compensation mechanism.In view of the above problems,using the DPSIR model(Drivers,Pressures,States,Impacts,Responses),this paper analyzed eucalyptus forest in Xizhi River Basin to assess the security of the Xizhi River ecological Basin,and finally concluded that the ecological status of Xizhi River Basin remains safe.

The Mitochondrial Genome of Raphanus sativus and Gene Evolution of Cruciferous Mitochondrial Types

To explore the mitochondrial genes of the Cruciferae family, the mitochondrial genome of Raphanus sativus （sat） was sequenced and annotated. The circular mitochondrial genome of sat is 239,723 bp and includes 33 protein-coding genes, three rRNA genes and 17 tRNA genes. The mitochondrial genome also contains a pair of large repeat sequences 5.9 kb in length, which may mediate genome reorga-nization into two sub-genomic circles, with predicted sizes of 124.8 kb and 115.0 kb, respectively. Furthermore, gene evolution of mitochondrial genomes within the Cruciferae family was analyzed using sat mitochondrial type （mitotype）, together with six other re-ported mitotypes. The cruciferous mitochondrial genomes have maintained almost the same set of functional genes. Compared with Cycas taitungensis （a representative gymnosperm）, the mitochondrial genomes of the Cruciferae have lost nine protein-coding genes and seven mitochondrial-like tRNA genes, but acquired six chloroplast-like tRNAs. Among the Cruciferae, to maintain the same set of genes that are necessary for mitochondrial function, the exons of the genes have changed at the lowest rates, as indicated by the numbers of single nucleotide polymorphisms. The open reading frames （ORFs） of unknown function in the cruciferous genomes are not conserved. Evolutionary events, such as mutations, genome reorganizations and sequence insertions or deletions （indets）, have resulted in the non- conserved ORFs in the cruciferous mitochondrial genomes, which is becoming significantly different among mitotypes. This work represents the first phylogenic explanation of the evolution of genes of known function in the Cruciferae family. It revealed significant variation in ORFs and the causes of such variation.

Self-generating nanogaps for highly effective surface-enhanced Raman spectroscopy

The fabrication of surface enhanced Raman spectroscopy(SERS)substrates with controlled high density hot spots still remains challenging.Herein,we report highly effective SERS substrates containing the self-generating(SG)nanogaps from polystyrene nanosphere monolayer through isotropic plasma etching.The emergence of multimode hot spots,i.e.,metal film over nanosphere(MFON)-like hot spots(closed gaps,0 nm),individual self-aligned hot spots(discrete gaps,>20 nm)and threedimensional(3D)hot spots(nanogaps,1-10 nm),makes the SG SERS substrates superior as compared to the traditional MFON or the well-ordered self-aligned SERS substrates in terms of enhancement,uniformity,and reproducibility.The SG SERS substrates can function as the excellent SERS platforms for trace molecule detection in the practical application fields.

A glutathione-triggered precision explosive system for improving tumor chemosensitivity

Stimuli-responsive delivery systems hold promise in cancer treatments.However,their application potential has been limited due to undesirable drug leaking during blood circulation and inefficient therapeutic efficacy in tumors,resulting in undesirable therapeutic outcomes.Herein,we have developed a novel redox-sensitive pegylated phospholipid,termed as DOPE-SS-PEG,which can form a glutathione(GSH)-triggered precision explosive system(GPS)for simultaneously improving circulation stability,tumor specificity,and chemosensitivity,leading to explosive anticancer effects.GPS is constructed of liposomal doxorubicin(DOX)functionalized with DOPE-SS-PEG and MnO_(2) nanoparticles,which can protect liposome structure in the presence of serum GSH(20μM),whereas converts to cationic liposome in response to intracellular GSH(10 mM),thereby enhancing circulation stability,tumor specificity,endosomal escape,and cytoplasmic delivery.Importantly,GPS can not only generate oxygen to relieve hypoxia and consequently enhance chemosensitivity,but quench GSH antioxidability to elevate the accruement of intracellular reactive oxygen species(ROS),leading to an explosion of oxidative stress induced cell injury.Particularly,in vivo studies show that GPS selectively accumulates in tumor tissues,effectively inhibits tumor growth,exhibits minimal systemic adverse effects,and consequently prolongs the survival time of tumor-bearing mice.Therefore,GPS is a unique stimuli-responsive treatment with programmed and on-demand drug delivery,as well as explosive therapeutic efficacy,and provides an intelligent anticancer treatment.

MoS_(x) nanowire networks derived from[Mo_(3)S_(13)]^(2−) clusters for efficient electrocatalytic hydrogen evolution

Precise design and synthesis of sub-nano scale catalysts with controllable electronic and geometric structures are pivotal for enhancing the hydrogen evolution reaction(HER)performance of molybdenum sulfide(MoS_(2))and unraveling its structure−activity relationship.By leveraging transition molybdenum polysulfide clusters as functional units for multi-level ordering,we successfully designed and synthesized MoS_(x)nanowire networks derived from[Mo_(3)S_(13)]^(2−) clusters via evaporationinduced self-assembly,which exhibit enhanced HER activity attributed to a high density of active sites and dynamic evolution behavior under cathodic potentials.MoS_(x) nanowire networks electrode yields a current density of 100 mA·cm^(−2) at 142 mV in 0.5 M H_(2)SO_(4).This work provides an attractive prospect for optimizing catalysts at the sub-nano scale and offers insights into a strategy for designing catalysts in various gas evolution reactions.