Zeolitic Imidazole Framework (ZIF)-Sponge Composite for Highly Efficient U(VI) Elimination.

Herein, a zeolitic imidazole framework (ZIF-67) composite was prepared by a rapid, simple and inexpensive situ hybridization technique applying polyurethane sponge (PU) as support, which was designated as ZIF-67-PU. The ZIF-67 nanoparticle was successfully supported on the surface of sponge skeletons mainly through electrostatic attraction as well as probable π-π stacking interactions with PAM modification of the sponge. The resultant ZIF-67-PU exhibited a remarkably enhanced U(VI) elimination capacity of 150.86 mg∙g-1 on the basis of the Langmuir isotherm model, in comparison to pristine sponge. Additionally, the mechanism for U(VI) elimination was mainly achieved through the complex reaction between C-N(H)/-OH groups in ZIF-67 and U(VI), based on XPS investigations. ZIF-67-PU represents a simple, feasible and low-cost disposal option for preparing ZIF-coated sponges of any shape that can enhance the U(VI) elimination capacity. Furthermore, this approach can be widely applied to the preparation of various kinds of MOF-sponges through this situ hybridization technique.

One-Dimensional Shaving-like BiVO4 Nanobelts: Synthesis, Characterization and Photocatalytic Activity with Methylene Blue.

One-dimensional shaving-like BiVO4 nanobelts were successfully synthesized via the oxide hydrothermal method (OHS), using V2O5 and Bi2O3 as raw materials and PEG 10000 (polyethylene glycol 10000) as a template. Multiple techniques, including XRD, SEM, TEM, HRTEM, UV-Vis, XPS, and photoelectrochemical measurements, were applied to characterize the obtained materials. The thickness of the BiVO4 nanobelt was approximately 10 nm, while the width was approximately 500 nm. EIS results showed that visible-light illumination caused the photogenerated charge of the BiVO4 nanobelts to have a faster transfer and a higher separation efficiency. Photocatalytic experiments indicated that with BiVO4 nanobelts as a catalyst, the degradation rate of MB (methylene blue) was close to 92.4%, and it disintegrated after two hours. Moreover, the pseudo-first-order kinetic model can be used to describe the photodecomposition reaction of MB catalysed by BiVO4 nanobelts. And this excellent photocatalytic activity of the shaving-like BiVO4 nanobelts may be related to their special morphology, narrow band gap (~2.19 eV), faster transfer and the separation efficiency of the photogenerated charge, leading to strong absorption in the visible region and improving the separation of the photogenerated electron-hole pairs. These novel monoclinic BiVO4 nanobelts exhibited great photocatalytic activity and are thus a promising candidate for application in visible-light-responsive photocatalysts.

The effect of selenium on antioxidant system in aquaculture animals.

There will be generated some adverse conditions in the process of acquculture farming with the continuous improvement of the intensive degree of modern aquaculture, such as crowding stress, hypoxia, and malnutrition, which will easily lead to oxidative stress. Se is an effective antioxidant, participating and playing an important role in the antioxidant defense system of fish. This paper reviews the physiological functions of selenoproteins in resisting oxidative stress in aquatic animals, the mechanisms of different forms of Se in anti-oxidative stress in aquatic animals and the harmful effects of lower and higher levels of Se in aquaculture. To summarize the application and research progress of Se in oxidative stress in aquatic animals and provide scientific references for its application in anti-oxidative stress in aquaculture.

Spatial-temporal changes in the degradation of marshes over the past 67 years.

Agricultural reclamation is widely regarded as a primary cause of marshes degradation. However, the process of marshes degradation on different geomorphology has rarely explored, which fail to explain the marshes degradation driven by natural restrictions in detail. The information deficiency unable propounded the targeted suggestions for the sustainable management of marshes. According to the development of China, we quantified the degradation rate of marshes on different geomorphic types from 1954 to 2020 in a typical transect in the Sanjiang Plain. The results indicated that (1) A total of 1633.92 km2 of marshes reduced from 1954 to 2020. And 97% (1582.35 km2) of marshes were converted to crop cultivation. The process of marshes degradation had obvious historical stages characteristics. The marshes degradation rate showed a trend of increasing first and then decreasing. The most serious period was 1995-2005 (6.29%) which was approximately 35 times of the period of before the reform and opening up (1954-1976) a minimal shrunk period. (2) The background of geological tectonic decided the whole trends in marshes degradation process. The degradation occurred first and worst in the meco-scale recent slow ascent region, and then extended to substantially recent slow subsidence region and the small-amplitude recent slow ascent region. (3) Significant location characteristics of marshes degradation reflected in this research. The spatial location of marshes degradation on the sub-regions sequentially consisted of alluvial plain, lower terrace, high floodplain, micro-knoll, low floodplain, and depressions. (4) Most of the existing marshes of the sub-Sanjiang Plain distribution in the national reserves. This study provides important scientific information for restoration and conservation of marshes.

[Identification of released population of Japanese flounder based on stable isotopes analysis]. / åŸºäºŽç¨³å®šåŒä½ç´ æŠ€æœ¯çš„å¢žæ®–æ”¾æµç‰™é²†ç¾¤ä½“é‰´åˆ«.

Japanese flounder (Paralichthys olivaceus) is an important releasing fish in the Yellow and Bohai Seas of China. The identification of wild and releasing population is the premise to evaluate the enhancement effects. In order to study the application of stable isotope in the identification of released P. olivaceus population, captured juveniles in the offshore releasing area of Qinhuangdao were distinguished into wild and released population using previous method (combination of morphology and molecular). Then, the contents of carbon and nitrogen stable isotope in muscle and otoliths (including the whole and the core region) were measured. The cultured population was set as control. The results showed that δ13C values (wild population: -17.19‰±0.73‰; released population: -17.10‰±0.61‰; cultured population: -20.75‰±0.07‰) and δ15N values (wild population: 11.81‰±0.38‰; released population: 11.62‰±0.48‰; cultured population: 8.64‰±0.60‰) of muscle and δ13C value (wild popu-lation: -4.47‰±0.35‰; released population: -4.63‰±0.29‰; cultured population: -6.59‰±0.58‰) of the whole otolith could be used to identify the cultured population, but could not be used to distinguish the wild from the released population. The δ13C value (wild population: -4.66‰±0.30‰; released population: -5.41‰±0.21‰; cultured population: -5.37‰±0.19‰) of the core region of otolith could be used to identify the wild popu-lation. The δ18O values of the whole and the core region of otolith from these three groups were overlapped and could not be used to distinguish different populations. Our results indicated that the δ13C value of the core area of otolith could be used to identify wild and released population, with application prospect in the identification of broodstocks participating in spawning migration. This study provided basic data and technical methods for evaluating early resources replenishment and the effects of Japanese flounder enhancement.

Discovery of Selective Inhibitors for In Vitro and In Vivo Interrogation of Skeletal Myosin II.

Myosin IIs, actin-based motors that utilize the chemical energy of adenosine 5'-triphosphate (ATP) to generate force, have potential as therapeutic targets. Their heavy chains differentiate the family into muscle (skeletal [SkMII], cardiac, smooth) and nonmuscle myosin IIs. Despite the therapeutic potential for muscle disorders, SkMII-specific inhibitors have not been reported and characterized. Here, we present the discovery, synthesis, and characterization of "skeletostatins," novel derivatives of the pan-myosin II inhibitor blebbistatin, with selectivity 40- to 170-fold for SkMII over all other myosin II family members. In addition, the skeletostatins bear improved potency, solubility, and photostability, without cytotoxicity. Based on its optimal in vitro profile, MT-134's in vivo tolerability, efficacy, and pharmacokinetics were determined. MT-134 was well-tolerated in mice, impaired motor performance, and had excellent exposure in muscles. Skeletostatins are useful probes for basic research and a strong starting point for drug development.

Role of GABAAR in the Transition From Acute to Chronic Pain and the Analgesic Effect of Electroacupuncture on Hyperalgesic Priming Model Rats.

Chronic pain is a costly health problem that impairs health-related quality of life when not effectively treated. Regulating the transition from acute to chronic pain is a new therapeutic strategy for chronic pain that presents a major clinical challenge. The underlying mechanisms of pain transition are not entirely understood, and strategies for preventing this transition are lacking. Here, a hyperalgesic priming model was used to study the potential mechanism by which γ-aminobutyric acid receptor type A (GABAAR) in the dorsal root ganglion (DRG) contributes to pain transition. Furthermore, electroacupuncture (EA), a modern method of acupuncture, was administered to regulate pain transition, and the mechanism underlying EA's regulatory effect was investigated. Hyperalgesic priming was induced by intraplanar injection of carrageenan (Car)/prostaglandin E2 (PGE2). The decrease in mechanical withdrawal threshold (MWT) induced by PGE2 returned to baseline 4 h after injection in NS + PGE2 group, and still persisted 24 h after injection in Car + PGE2 group. Lower expression of GABAAR in the lumbar DRG was observed in the model rats. Furthermore, activating or blocking GABAAR could reversed the long-lasting hyperalgesia induced by Car/PGE2 injection or produced a persistent hyperalgesia. In addition, GABAAR may be involved in Protein Kinase C epsilon (PKCε) activation in the DRG, a mark molecular of pain transition. EA considerably increased the mechanical pain thresholds of hyperalgesic priming model mammals in both the acute and chronic phases. Furthermore, EA upregulated the expression of GABAAR and inhibited the activation of PKCε in the DRG. In addition, peripheral administration of picrotoxin blocked the analgesic effect of EA on the model rats and abolished the regulatory effect of EA on PKCε activation. These findings suggested that GABAAR plays a key role in both the transition from acute to chronic pain and the analgesic effect of EA on hyperalgesic priming.

Enhancing GaN LED Efficiency through Nano-Gratings and Standing Wave Analysis.

Based on our recent work, this paper reviews our theoretical study on gallium nitride (GaN) light-emitting-diode (LED). The focus of the paper is to improve LED light extraction efficiency through various nano-grating designs. The gratings can be designed at different locations, such as at the top, the middle, and the bottom, on the LED. They also can be made of different materials. In this study, we first present a GaN LED error-grating simulation model. Second, nano Indium Tin Oxide (ITO) top gratings are studied and compared with conventional LED (CLED) using standing wave analysis. Third, we present results related to a patterned sapphire substrate (PSS), SiO2 Nanorod array (NR), and Ag bottom reflection layer. Finally, we investigate the nano-top ITO grating performance over different wavelengths to validate our design simulation, which focusing on a single wavelength of 460 nm.

Evaluation of riparian condition of Songhua River by integration of remote sensing and field measurements.

Riparian zone is crucial to the health of streams and their surrounding environment. Evaluation of riparian condition is essential to achieve and maintain good stream health, as well as to sustain ecological functions that riparian areas provide. This manuscript is aimed to evaluate riparian conditions of Songhua River, the fifth longest river in China, using physical structural integrality (PSI) values derived from remote sensing and validated by field measurements. The variation and clusters of PSI values were discriminated by the spatial statistics to quantify variation of riparian condition in each measurement section. Evaluation results derived from 13 measurement sections indicated that over 60% of the riparian zones have been disturbed by human activities. Analysis of land use patterns of riparian zone in the cold and hot spots found that land-use patterns had an important effect on riparian condition. The build-up and farmland areas had been the main human disturbances to the riparian condition, which were increased from 1976 to 2013. The low-low clusters (low PSI values with low neighbors) of PSI values can be implemented to identify the vulnerability of the riparian zone.

Microstructure, corrosion and tribological and antibacterial properties of Ti-Cu coated stainless steel.

A Ti-Cu coated layer on 316L stainless steel (SS) was obtained by using the Closed Field Unbalanced Magnetron Sputtering (CFUBMS) system to improve antibacterial activity, corrosion and tribological properties. The microstructure and phase constituents of Ti-Cu coated layer were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and glow discharge optical emission spectrometry (GDOES). The corrosion and tribological properties of a stainless steel substrate, SS316L, when coated with Ti-Cu were investigated in a simulated body fluid (SBF) environment. The viability of bacteria attached to the antibacterial surface was tested using the spread plate method. The results indicate that the Ti-Cu coated SS316L could achieve a higher corrosion polarization resistance and a more stable corrosion potential in an SBF environment than the uncoated SS316L substrate. The desirable corrosion protection performance of Ti-Cu may be attributable to the formation of a Ti-O passive layer on the coating surface, protecting the coating from further corrosion. The Ti-Cu coated SS316L also exhibited excellent wear resistance and chemical stability during the sliding tests against Si3N4 balls in SBF environment. Moreover, the Ti-Cu coatings exhibited excellent antibacterial abilities, where an effective reduction of 99.9% of Escherichia coli (E.coli) within 12h was achieved by contact with the modified surface, which was attributed to the release of copper ions when the Ti-Cu coatings are in contact with bacterial solution.

[Effects of echinacoside on extracellular acetylcholine and choline levels of hippocampus and striatum of cerebral ischemia rats].

The aim of this study is to investigate the effect of echinacoside (ECH) on cholinergic neurotransmitter extracellular of hippocampus and striatum and its possible mechanisms of neuro-protective effect against vascular dementia rats. In this study brain microdialysis technique combined with HPLC-IMER-ECD (high-performance liquid chromatography-immobilized enzyme reactor-electrochemical detector) was used. The bilateral common carotid arteries occluded in two times operation at 72 h interval for vascular dementia model rats were used and the successful vascular dementia model rats were examined by Morris water maze. The content of acetylcholine (ACh) and choline (Ch) of microdialysate extracellular of hippocampus and striatum was determined by HPLC-IMER-ECD and the AChE activity in the hippocampus was measured. The results showed that the success rate of vascular dementia model was 83.08% after six weeks; the results also showed that echinacoside and galantamine could increase the content of ACh and reduce the content of Ch extracellular of hippocampus and striatum significantly and the AChE activity increased significantly compared with that of the model group. The results suggested that echinacoside could promote the recovery of cholinergic neurotransmitter levels in vascular dementia rats' brain, which may be one of the mechanisms of neuro-protection.

Asymmetric synthesis and absolute configuration of streptophenazine G.

The asymmetric synthesis of the antibacterial natural product, streptophenazine G, has been achieved by employing asymmetric alkylation and asymmetric aldol reactions using chiral oxazolidinones as the key steps. The originally proposed structure for streptophenazine G has been revised, and its absolute configuration has been determined to be 1'S,2'R,6'S. The asymmetric total synthesis of 6'-epi-streptophenazine G is also described.

The revised structure, total synthesis, and absolute configuration of streptophenazine A.

A total synthesis of both diastereomers of the originally proposed structure for streptophenazine A (1) has been achieved. However, both synthetic compounds are different from the natural product. Re-examination of NMR data reported for streptophenazine A and a concise total synthesis of both diastereomers of 17 (17a and 17b) led to the structural revision of streptophenazine A to 17b. Asymmetric synthesis of (-)-streptophenazine A was also conducted, and its absolute configuration was determined to be 1'S,2'R.

A concise synthesis of enantiopure circumdatins E, H and J.

A concise total synthesis of enantiopure circumdatins E, H and J has been developed using a reductive cyclization of chiral N-prolinoyl-2-nitrobenzamides to construct the core quinazolinone ring.

Binding of matrix metalloproteinase inhibitors to extracellular matrix: 3D-QSAR analysis.

Binding to the extracellular matrix, one of the most abundant human protein complexes, significantly affects drug disposition. Specifically, the interactions with extracellular matrix determine the free concentrations of small molecules acting in tissues, including signaling peptides, inhibitors of tissue remodeling enzymes such as matrix metalloproteinases, and other drug candidates. The nature of extracellular matrix binding was elucidated for 63 matrix metalloproteinase inhibitors, for which the association constants to an extracellular matrix mimic were reported here. The data did not correlate with lipophilicity as a common determinant of structure-nonspecific, orientation-averaged binding. A hypothetical structure of the binding site of the solidified extracellular matrix surrogate was analyzed using the Comparative Molecular Field Analysis, which needed to be applied in our multi-mode variant. This fact indicates that the compounds bind to extracellular matrix in multiple modes, which cannot be considered as completely orientation-averaged and exhibit structural dependence. The novel comparative molecular field analysis models, exhibiting satisfactory descriptive and predictive abilities, are suitable for prediction of the extracellular matrix binding for the untested chemicals, which are within applicability domains. The results contribute to a better prediction of the pharmacokinetic parameters such as the distribution volume and the tissue-blood partition coefficients, in addition to a more imminent benefit for the development of more effective matrix metalloproteinase inhibitors.

Synthesis and evaluation of novel heterocyclic MMP inhibitors.

A variety of novel heterocyclic compounds were synthesized and evaluated for MMP inhibition. Broad spectrum inhibition of MMPs 1, 2, 9, and 12 was found with pyridinone-based compounds while N-heterocyclic triazoles and tetrazoles were largely ineffective. A highly selective tetrazole inhibitor for MMP-2 was discovered.

Study on tandem repeat sequence variation in sheep mtDNA D-loop region.

The 75-nt-long tandem repeat sequence in the control region of mtDNA of 77 individuals, of which 69 were from different indigenous sheep breeds in China and 8 were from imported breeds, was sequenced and analyzed to investigate the origin and differentiation of Chinese indigenous sheep breeds and also the genetic diversities and relationships among them. A total of 28 variable sites were detected within 309 repeated sequences, among which 7 sites were singleton variable sites with two variants, 1 site was a singleton variable site with three variants, and 20 sites were parsimony informative sites with two variants. A total of 63 haplotypes were sorted from 28 polymorphic sites, among which two main and basic haplotypes, namely, Hap 1 and Hap 3 were present at a much higher proportion, at 12.94% and 30.42%, respectively. It could be inferred that Chinese indigenous sheep breeds originated from two maternal ancestors because of the maternal inheritance characteristics of the mtDNA. Altay sheep and Kazakstan sheep are closely related and do not differentiate significantly. Mongolian sheep and Ujumuqin sheep also share a close relationship. Tibetan sheep, Mongolian sheep, and Ujumuqin sheep have lower genetic diversity than Altay sheep and Kazakstan sheep.