Synergistic effect of 1-(2,5-dioxoimidazolidin-4-yl)urea and Tween-80 towards the corrosion mitigation of mild steel in HCl

The inhibition performance and synergistic inhibition effect of DMU with Tween-80 on the corrosion of mild steel in 1 M HCl was studied for the first time.

Towards high-energy, high-resolution computed tomography via a laser driven micro-spot gamma-ray source

Computed Tomography (CT) is a powerful method for non-destructive testing (NDT) and metrology awakes with expanding application fields. To improve the spatial resolution of high energy CT, a micro-spot gamma-ray source based on bremsstrahlung from a laser wakefield accelerator was developed. A high energy CT using the source was performed, which shows that the resolution of reconstruction can reach 100 μm at 10% contrast. Our proof-of-principle demonstration indicates that laser driven micro-spot gamma-ray sources provide a prospective way to increase the spatial resolution and toward to high energy micro CT. Due to the advantage in spatial resolution, laser based high energy CT represents a large potential for many NDT applications.

Limits on Light Weakly Interacting Massive Particles from the First 102.8 kg×day Data of the CDEX-10 Experiment

We report the first results of a light weakly interacting massive particles (WIMPs) search from the CDEX-10 experiment with a 10 kg germanium detector array immersed in liquid nitrogen at the China Jinping Underground Laboratory with a physics data size of 102.8 kg day. At an analysis threshold of 160 eVee, improved limits of 8×10^{-42} and 3×10^{-36}  cm^{2} at a 90% confidence level on spin-independent and spin-dependent WIMP-nucleon cross sections, respectively, at a WIMP mass (m_{χ}) of 5  GeV/c^{2} are achieved. The lower reach of m_{χ} is extended to 2  GeV/c^{2}.

Asymmetric total synthesis of talienbisflavan A

The first asymmetric total syntheses of talienbisflavan A and bis-8,8'-epicatechinylmethane as well as a facile synthesis of bis-8,8'-catechinylmethane has been accomplished from readily available starting materials by using a newly developed direct regioselective methylenation of catechin derivatives as one of the key steps.

Efficient Synthesis of Functionalized 4H-Chromenes via an Fe(OTf)3-Catalyzed Cyclization Reaction of Phenols and Ketones

The iron(III) triflate catalyzed cyclization reaction of phenols and ketones is described; the reaction provides a direct approach to 4H-chromene derivatives. 4H-Chromene is an important structural fragment of many pharmaceuticals, natural products, and functional materials. The 4H-chromene synthetic protocol possesses many advantages, such as using readily available and inexpensive starting materials and a non-toxic catalyst, high selectivity, and operational simplicity, which offer­ attractive industrial prospects from the point of view of green and sustainable chemistry.

Gravimetric, electrochemical and surface studies on the anticorrosive properties of 1-(2-pyridyl)-2-thiourea and 2-(imidazol-2-yl)-pyridine for mild steel in hydrochloric acid

1-(2-Pyridyl)-2-thiourea and 2-(imidazol-2-yl)-pyridine are described here for the first time as inhibitors of mild steel corrosion in acidic medium.

Regioselective 1,2-Diol Rearrangement by Controlling the Loading of BF3·Et2O and Its Application to the Synthesis of Related Nor-Sesquiterene- and Sesquiterene-Type Marine Natural Products

The regiocontrolled rearrangement of 1,2-diols has been achieved by controlling the loading of BF₃·Et₂O. Its applicability is showcased by the divergent synthesis of austrodoral, austrodoric acid, and 8-epi-11-nordriman-9-one, as well as a formal synthesis of siphonodictyal B and liphagal. A new light is shed on piancol-type rearrangements that will be useful in diversity-oriented synthesis of related natural products.

Large-charge quasimonoenergetic electron beams produced by off-axis colliding laser pulses in underdense plasma

Electrons can be efficiently injected into a plasma wave by colliding two counterpropagating laser pulses in a laser wakefield acceleration. However, the generation of a high-quality electron beam with a large charge is difficult in the traditional on-axis colliding scheme due to the growth of the electron beam duration coming from the increase of the beam charge. To solve this problem, we propose an off-axis colliding scheme, in which the collision point is away from the axis of the driver pulse. We show that the electrons injected from the off-axis region are highly concentered on the tail of the bubble even for a large trapped charge, thus feeling almost the same accelerating field. As a result, quasimonoenergetic electron beams with a large charge can be produced. The validity of this scheme is confirmed by both the particle-in-cell simulations and the Hamiltonian model. Furthermore, it is shown that a Laguerre-Gauss (LG) laser can be adopted as the injection pulse to realize the off-axis colliding injection in three dimensions symmetrically, which may be useful in simplifying the technical layout of the real experiment setup.

[Gα11 expression and effect of sildenafil in muscularization of non-muscular pulmonary arterioles in rat with pulmonary arterial hypertension]

OBJECTIVE

To investigate expression changes and role of Gα11 protein in the processes of muscularization of non-muscular pulmonary arterioles and effect of sildenafil intervention in rats with pulmonary arterial hypertension (PAH).

METHODS

Thirty SD rats were randomly divided into three groups, including normal control group, monocrotaline (MCT) group and sildenafil group; PAH model was prepared with 50 mg/kg MCT treatment for 4 weeks in the MCT group, and these rats were treated by 25 mg/kg sildenafil for 2 weeks after PAH formation in the sildenafil group, and the normal control group were treated with the equal amounts of physiological saline instead of monocrotaline; pulmonary artery pressure was measured with jugular vein catheterization; hematoxylin and eosin (HE) staining method was used to detect the pulmonary arteriolar morphology and vascular tissue parameters; expression of the target Gα11 protein, vascular smooth muscle marker osteopontin (OPN) and proliferation marker proliferating cell nuclear antigen (PCNA) was detected by Western blot.

RESULTS

Pulmonary artery mean pressure (mPAP), non-muscular pulmonary arterioles wall thickness index (TI) and area index (AI) of the MCT group were higher than those of the normal control group[(27.43±3.97) vs (11.93±1.52) mmHg (1 mmHg=0.133 kPa), 0.49±0.07 vs 0.31±0.09 and 0.74±0.05 vs 0.45±0.10](all P<0.05), and meanwhile the expression levels of Gα11 and the related proteins including OPN and PCNA were significantly enhanced. mPAP, TI and AI[(18.59±1.44) mmHg, 0.39±0.09 and 0.56±0.04]of the sildenafil group were all lower than those of the MCT group (all P<0.05), and furthermore, expressions of Gα11, OPN and PCNA also reduced in line with these changes.

CONCLUSION

Gα11 protein plays a role in the development of PAH and pulmonary non-muscular arteriole muscularization, and sildenafil effectively suppresses PAH and pulmonary vascular remodeling by inhibiting Gα11 expression.

Diversity and antimicrobial activity of endophytic fungi isolated from Cephalotaxus hainanensis Li, a well-known medicinal plant in China

About 1051 endophytic fungi were isolated from leaves, branches, barks and stems of Cephalotaxus hainanensis Li from four sites in Hainan, China. The fungi were identified as 21 genera by morphology and ITS sequences. One dominant species was Phomopsis quercella in Hainan Tropical Botanical Garden and Bawangling Nature Reserve, with relative frequency of 42·06 and 34·88% respectively. Another dominant species was Colletotrichum boninense in Wuzhishan and Jianfengling Nature Reserves, with relative frequency of 36·84 and 46·97% respectively. Among the selected 21 endophytic fungi, 17 strains (80·95%) had activity against at least one pathogenic bacteria, and 14 strains (66·67%) exhibited activity against at least one fungal pathogens. Neonectria macroconidialis showed strong inhibition against Staphylococcus aureus (inhibition zone being 20 mm), Bacillus subtilis (14 mm) and Streptococcus agalactiae (28 mm). Xylaria sp. showed strong inhibition against Escherichia coli (20 mm), Rhizoctonia solani (20 mm) and Sclerotinia sclerotiorum (17 mm). Verticillium bulbillosum showed great activity against Strep. agalactiae (32 mm) and Fusarium oxysporum (22 mm). These endophytic fungi showed potentials in medicine development.

SIGNIFICANCE AND IMPACT OF THE STUDY

Endophytic fungi from medicinal plants are an important source of novel and viable drugs. Cephalotaxus hainanensis Li is well known for leukaemia treatment and its endophytic fungi were isolated to investigate the diversity and antimicrobial activity. It was found that Ce. hainanensis Li had rich endophytic fungi, and some fungi showed strong antimicrobial activity against certain pathogens. These fungi can be used in medicine development.