Calcium carbonate: controlled synthesis, surface functionalization, and nanostructured materials.

Calcium carbonate (CaCO3) is an important inorganic mineral in biological and geological systems. Traditionally, it is widely used in plastics, papermaking, ink, building materials, textiles, cosmetics, and food. Over the last decade, there has been rapid development in the controlled synthesis and surface modification of CaCO3, the stabilization of amorphous CaCO3 (ACC), and CaCO3-based nanostructured materials. In this review, the controlled synthesis of CaCO3 is first examined, including Ca2+-CO32- systems, solid-liquid-gas carbonation, water-in-oil reverse emulsions, and biomineralization. Advancing insights into the nucleation and crystallization of CaCO3 have led to the development of efficient routes towards the controlled synthesis of CaCO3 with specific sizes, morphologies, and polymorphs. Recently-developed surface modification methods of CaCO3 include organic and inorganic modifications, as well as intensified surface reactions. The resultant CaCO3 can then be further engineered via template-induced biomineralization and layer-by-layer assembly into porous, hollow, or core-shell organic-inorganic nanocomposites. The introduction of CaCO3 into nanostructured materials has led to a significant improvement in the mechanical, optical, magnetic, and catalytic properties of such materials, with the resultant CaCO3-based nanostructured materials showing great potential for use in biomaterials and biomedicine, environmental remediation, and energy production and storage. The influences that the preparation conditions and additives have on ACC preparation and stabilization are also discussed. Studies indicate that ACC can be used to construct environmentally-friendly hybrid films, supramolecular hydrogels, and drug vehicles. Finally, the existing challenges and future directions of the controlled synthesis and functionalization of CaCO3 and its expanding applications are highlighted.

Endoscopic cadaveric analysis of the origin of the ophthalmic artery.

PURPOSE: The ophthalmic artery is often involved in suprasellar and parasellar surgeries, but the anatomical structure where the ophthalmic artery originates has not been fully clarified from the perspective of an endoscopic endonasal approach (EEA). METHODS: A total of 10 fresh cadaveric heads (20 sides) were dissected through an EEA, and the origin of the bilateral ophthalmic arteries and their adjacent structures were observed from a ventral view. The origin of the ophthalmic artery in 50 healthy people was retrospectively studied on computed tomography angiography imaging. RESULTS: The ophthalmic artery originated from the intradural segment (75%), paraclinoid segment (15%), or parasellar segment (10%) of the internal carotid artery. The cross-sectional view of the internal carotid artery through the EEA showed that the ophthalmic artery originated from the middle 1/3 (75%) or medial 1/3 (25%) of the upper surface of the internal carotid artery. On computed tomography angiography, the ophthalmic artery originated from the middle 1/3 (77%) and medial 1/3 (22%) of the upper surface of the internal carotid artery. All ophthalmic arteries were near the level of the distal dural ring (DDR) of the internal carotid artery, that is, within 3 mm above or below the DDR. CONCLUSIONS: The ophthalmic artery usually originates in the middle 1/3 of the upper surface of the intradural segment of the internal carotid artery within 3 mm of the DDR. The ophthalmic artery can be protected to the utmost extent after its origin is identified through an EEA.

Evolution of Chemical Bonding and Crystalline Swelling-Shrinkage of Montmorillonite upon Temperature Changes Probed by in Situ Fourier Transform Infrared Spectroscopy and X-ray Diffraction.

Clay minerals are distributed in Earth's crust and troposphere and in Martian crust where temperature varies. Understanding the changes of chemical bonding and crystalline swelling-shrinkage of montmorillonite (Mnt) upon temperature changes is fundamental for studying its surface reactivity and interaction in specific surroundings. However, such an issue remains poorly understood. Here, in situ high- and low-temperature Fourier transform infrared (HT- and LT-FTIR) spectroscopy and X-ray diffraction (HT- and LT-XRD) were performed to study the evolution of chemical bonding and crystalline swelling-shrinkage of sodium-montmorillonite (NaMnt) upon temperature changes. The FTIR results show that the hydroxyl content in NaMnt decreased when the temperature increased from 20 to 700 °C, while it is independent of temperature from 0 to -150 °C. The formation of hydroxyls at the "broken" layer edges of NaMnt is related to adsorbed water molecules on the surfaces, and its content increased when the particle size of the NaMnt decreased. The water molecules in the interlayer space of NaMnt could bond to the tetrahedral sheet of NaMnt through Si2O-H2O bonds. HT- and LT-XRD results reveal that all of those water molecules in NaMnt were removed after heating to 100 °C in the heating chamber. The NaMnt was transformed from a state of monolayer interlayer water molecules at 20 °C to a dehydrated state at 100 °C, and then to a dehydroxylated state at 700 °C. Accordingly, the basal spacings of NaMnt were changed from 1.27 to 0.97 nm and then to 0.96 nm, respectively. When NaMnt was cooled from 20 to -268 °C, a crystalline swelling of NaMnt occurred with an increase of 0.03 nm of basal spacing. This work demonstrates that high/low temperature has a remarkable effect on the hydroxyls and the water molecules in NaMnt, which in turn affects its swelling-shrinkage performance. These findings provide some in-depth understanding of the changes of chemical bonding and crystalline swelling-shrinkage of montmorillonite upon temperature changes and the reasons behind these, which might be helpful for the design of engineering Mnt in high-/low-temperature applications.

Z-Score Reference Ranges for Umbilical Vein Diameter and Blood Flow Volume in Normal Fetuses.

OBJECTIVES: To establish Z-scores for the diameter and blood flow volume of the umbilical vein (UV) in normal fetuses. METHODS: This was a prospective study involving 907 normal fetuses. We measured the diameter (Duv) of two different segments of the UV (FUV: the free loop of the UV; FIUV: the fetal intra-abdominal UV). Next, we calculated the blood flow volume (Quv). Z-scores were created for both Duv and Quv using gestational age, femur length, and biparietal diameter as independent variables. RESULTS: We successfully acquired 858 (94.6%) normal fetal measurements. Between 20 and 39 weeks, the Duv of the FUV and FIUV increased from 0.38 to 0.80 cm and from 0.33 to 0.70 cm, respectively. The Quv of the FUV and FIUV increased from 32.66 to 381.88 ml/min and from 31.50 to 360.15 ml/min, respectively. Linear or quadratic regression models were best fitted between the parameters of UV and the independent variables. Z-scores were successfully determined for both the Duv and Quv. CONCLUSIONS: The calculation of Z-scores for the Duv and Quv is simple by applying standard statistical methods. These Z-scores may be useful to evaluate placental circulation and provide a rationale for monitoring and evaluating the prognosis of fetuses.

SRPK1/AKT axis promotes oxaliplatin-induced anti-apoptosis via NF-κB activation in colon cancer.

BACKGROUND: Colorectal cancer is the third most common diagnosis. Oxaliplatin is used as first-line treatment of colon cancer. However, oxaliplatin resistance greatly reduces its therapeutic effect. SRPK1 involves in pre-mRNA splicing and tumorigenesis. How SRPK1 mediates drug resistance in colon cancer is unknown. METHODS: The expression of SRPK1 was analyzed in the TCGA and the CPTAC pan-cancer samples and detected in colon cancer cell lines and tissues by IHC and western blot. The MTT and TUNEL assay were used to verify the anti-apoptosis ability of colon cancer cell. The activation of NF-κB was determined by luciferase assay and qRT-PCR. AKT, IKK, IκB and their phosphorylation level were verified by western blot. RESULTS: We found that SRPK1 expression was the second highest in TCGA and the CPTAC pan-cancer samples. The mRNA and protein levels of SRPK1 were increased in tissues from patients with colon cancer. SRPK1 was associated with clinical stage and TNM classifications in 148 cases of colon cancer patients. High SRPK1 levels correlated with poor prognosis (p < 0.001). SRPK1 overexpression enhanced the anti-apoptosis ability of colon cancer cells, whereas SRPK1 silencing had the opposite effect under oxaliplatin treatment. Mechanistically, SRPK1 enhances IKK kinase and IκB phosphorylation to promote NF-κB nuclear translocation to confer oxaliplatin resistance. CONCLUSIONS: Our findings suggest that SRPK1 participates in colon cancer progression and enhances the anti-apoptosis capacity to induce drug resistance in colon cancer cells via NF-κB pathway activation, and thus might be a potential pharmaceutically target for colon cancer treatment.

Rapid detection of color-treated pearls and separation of pearl types using fluorescence analysis.

Pearl identification plays a key role to maintain transparency in the gem industry by disclosing potential color treatments and classifying pearl species. Current techniques for pearl identification have been limited by expensive instrumentations and long measurement time, severely restricting their use outside of major gemological laboratories. There is a strong demand for simple and inexpensive identification instruments designed for non-specialized users and small-scale gemological laboratories. For this purpose, we demonstrate a portable fluorescence spectroscopy for pearl treatment detection and species classification based on pearl's nacre fluorescence detection. This device can be used to rapidly separate naturally colored pearls from treated colored pearls, detect potential treatments applied to white colored pearls, and separate pearls between certain species in seconds, based on their differences in nacre fluorescence intensity. The system enables noninvasive testing of loose pearls, pearl strands, and mounted pearl jewelry under normal office lighting conditions. The experimental prototype demonstrates high accuracy for automatic pearl color treatment screening, referring 100% of the treated colored pearls. Furthermore, similar protocols can be applied to evaluate popular pearl enhancements such as bleaching and to extend its application to separate akoya pearls and their South Sea counterparts.

Ionic Functionalization of Multivariate Covalent Organic Frameworks to Achieve an Exceptionally High Iodine-Capture Capacity.

Adsorption-based iodine (I2 ) capture has great potential for the treatment of radioactive nuclear waste. In this study, we apply a "multivariate" synthetic strategy to construct ionic covalent organic frameworks (iCOFs) with a large surface area, high pore volume, and abundant binding sites for I2 capture. The optimized material iCOF-AB-50 exhibits a static I2 uptake capacity of 10.21 g g-1 at 75 °C and a dynamic uptake capacity of 2.79 g g-1 at ≈400 ppm I2 and 25 °C, far exceeding the performances of previously reported adsorbents under similar conditions. iCOF-AB-50 also exhibits fast adsorption kinetics, good moisture tolerance, and full reusability. The promoting effect of ionic groups on I2 adsorption has been elucidated by experimentally identifying the iodine species adsorbed at different sites and calculating their binding energies. This work demonstrates the essential role of balancing the textural properties and binding sites of the adsorbent in achieving a high I2 capture performance.

A Novel Water-Shore-Line Detection Method for USV Autonomous Navigation.

For the navigation of an unmanned surface vehicle (USV), detection and recognition of the water-shore-line (WSL) is an important part of its intellectualization. Current research on this issue mainly focuses on the straight WSL obtained by straight line fitting. However, the WSL in the image acquired by boat-borne vision is not always in a straight line, especially in an inland river waterway. In this paper, a novel three-step approach for WSL detection is therefore proposed to solve this problem through the information of an image sequence. Firstly, the initial line segment pool is built by the line segment detector (LSD) algorithm. Then, the coarse-to-fine strategy is used to obtain the onshore line segment pool, including the rough selection of water area instability and the fine selection of the epipolar constraint between image frames, both of which are demonstrated in detail in the text. Finally, the complete shore area is generated by an onshore line segment pool of multi-frame images, and the lower boundary of the area is the desired WSL. In order to verify the accuracy and robustness of the proposed method, field experiments were carried out in the inland river scene. Compared with other detection algorithms based on image processing, the results demonstrate that this method is more adaptable, and can detect not only the straight WSL, but also the curved WSL.

Insights into the Rheological Behavior of Aqueous Dispersions of Synthetic Saponite: Effects of Saponite Composition and Sodium Polyacrylate.

Synthetic saponite (Sap) easily delaminates in water to form a transparent sol and hydrogel with excellent rheological performance and is thus widely used in paints, cosmetics, and nanomaterials. The thixotropic property of Sap hydrogels is heavily dependent on the nature of Sap and the external electrolyte and polyelectrolyte; yet, details on the relationship between rheological behaviors of saponite hydrogels and Sap composition and polyelectrolyte remain unclear. In this work, thixotropic rheological behaviors of a series of synthetic Sap hydrogels, with and without added sodium polyacrylate polyelectrolyte (NaPA), were investigated. The Sap samples, with a Si/Al molar ratio from 5 to 25, were successfully synthesized using hydrothermal methods and characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The rheological performances of aqueous Sap dispersions and particle sizes and ζ-potentials of Sap were measured. The results showed that the crystallinity of the Sap increased with an increasing Si/Al molar ratio. All Sap samples, with the exception of the Sap with a Si/Al molar ratio of 5, dispersed well in water (3 wt %) to form hydrogels. The rheological behaviors of the hydrogels were related to the chemical composition and the layer charge of the Sap. The Sap with a Si/Al molar ratio of 25 had higher viscosity due to improved delamination. The addition of the NaPA, an anionic polyelectrolyte, into the hydrogels decreased the viscosity and altered the thixotropic properties such that the hydrogel becomes a sol. The addition of NaPA facilitated the dispersion and delamination of Sap, because under the electric field of negatively charged Sap particles in the hydrogel, the anionic NaPA was instantaneously polarized and thereby entered the hydration layer of the Sap particles.

A Multi-Feature and Multi-Level Matching Algorithm Using Aerial Image and AIS for Vessel Identification.

In order to monitor and manage vessels in channels effectively, identification and tracking are very necessary. This work developed a maritime unmanned aerial vehicle (Mar-UAV) system equipped with a high-resolution camera and an Automatic Identification System (AIS). A multi-feature and multi-level matching algorithm using the spatiotemporal characteristics of aerial images and AIS information was proposed to detect and identify field vessels. Specifically, multi-feature information, including position, scale, heading, speed, etc., are used to match between real-time image and AIS message. Additionally, the matching algorithm is divided into two levels, point matching and trajectory matching, for the accurate identification of surface vessels. Through such a matching algorithm, the Mar-UAV system is able to automatically identify the vessel's vision, which improves the autonomy of the UAV in maritime tasks. The multi-feature and multi-level matching algorithm has been employed for the developed Mar-UAV system, and some field experiments have been implemented in the Yangzi River. The results indicated that the proposed matching algorithm and the Mar-UAV system are very significant for achieving autonomous maritime supervision.

Autonomous Visual Perception for Unmanned Surface Vehicle Navigation in an Unknown Environment.

Robust detection and recognition of water surfaces are critical for autonomous navigation of unmanned surface vehicles (USVs), since any none-water region is likely an obstacle posing a potential danger to the sailing vehicle. A novel water region visual detection method is proposed in this paper. First, the input image pixels are clustered into different regions and each pixel is assigned a label tag and a confidence value by adaptive multistage segmentation algorithm. Then the resulting label map and associated confidence map are fed into a convolutional neural network (CNN) as training samples to train the network online. Finally, the online trained CNN is used to segment the input image again but with greater precision and stronger robustness. Compared with other deep-learning image segmentation algorithms, the proposed method has two advantages. Firstly, it dispenses with the need of manual labeling training samples which is a costly and painful task. Secondly, it allows real-time online training for CNN, making the network adaptive to the navigational environment. Another contribution of this work relates to the training process of neuro network. An effective network training method is designed to learn from the imperfect training data. We present the experiments in the lake with a various scene and demonstrate that our proposed method could be applied to recognize the water region in the unknown navigation environment automatically.

Catheter-Based Computed Tomography Angiography in Anterolateral Thigh Perforator Mapping of Chinese Patients.

BACKGROUND: During reconstructive surgery, anterolateral thigh (ALT) flap harvest is challenging due to variation and uncertainty in perforator distribution. We performed a pilot study to identify the predictive value of catheter-based computed tomography angiography (C-CTA) and traditional CTA (T-CTA) in ALT perforator mapping for patients whose ALT perforators were difficult to identify. METHODS: Thirty-four consecutive T-CTA/C-CTA-mapped ALT flaps were evaluated for extremity reconstruction. The perforator location, origin, and course were compared between T-CTA/C-CTA imaging and intraoperative findings. The mapping efficiency of T-CTA and C-CTA was compared thoroughly. RESULTS: Among the 34 ALT thigh flaps, 117 (36) of the 130 perforators identified intraoperatively were visible on C-CTA (T-CTA) in a subgroup of Chinese limb trauma patients with limited activity. C-CTA showed a satisfactory efficiency in perforator mapping, which was much better than the efficiency of T-CTA. C-CTA also showed a much better sensitivity (90.00 vs. 27.69%), specificity (94.74 vs. 66.67%), and accuracy (91.07 vs. 36.69%), and a much lower false-positive (1.68 vs. 26.53%), and false-negative rate (10.00 vs. 72.31%). Moreover, C-CTA could accurately predict the origin and septocutaneous or intramuscular course in all identified perforators. All flaps were elevated successfully and survived. CONCLUSION: C-CTA outperforms T-CTA in the preoperative perforator mapping of ALT flaps in a subgroup of Chinese limb trauma patients. C-CTA should be the method of choice for perforator mapping in patients whose ALT flaps are intended for extremity reconstruction.

Serine-arginine protein kinase 1 promotes a cancer stem cell-like phenotype through activation of Wnt/ß-catenin signalling in NSCLC.

Cancer stem cells (CSCs) are commonly associated with cancer recurrence and metastasis that occurs in up to 30-55% of non-small-cell lung carcinoma (NSCLC) patients. Herein, we showed that serine-arginine protein kinase 1 (SRPK1) was highly expressed at both the mRNA and the protein levels in human NCSLC. SRPK1 was associated with the clinical features of human NSCLC, including clinical stage (p < 0.001) and T (p = 0.001), N (p = 0.007), and M (p = 0.001) classifications. Ectopic overexpression of SRPK1 promoted the acquisition of a stem cell-like phenotype in human NSCLC cell lines cultured in vitro. Overexpression of SRPK1 increased sphere formation and the proportion of side-population cells that exclude Hoechst dye. Conversely, SRPK1 silencing reduced the number of spheres and the proportion of side-population cells. Mouse studies indicated that SRPK1 promoted NSCLC cell line tumour growth and SRPK1 overexpression reduced the number of tumour cells required to initiate tumourigenesis in vivo. Mechanistically, gene set enrichment analysis showed that Wnt/ß-catenin signalling correlated with SRPK1 mRNA levels and this signalling pathway was hyperactivated by ectopic SRPK1 expression in NSCLC cell lines. Immunofluorescence demonstrated that SRPK1 enhanced ß-catenin accumulation in the nuclei of NSCLC cell lines, and inhibition of ß-catenin signalling abrogated the SRPK1-induced stem cell-like phenotype. Together, our findings suggest that SRPK1 promotes a stem cell-like phenotype in NSCLC via Wnt/ß-catenin signalling. Moreover, SRPK1 may represent a novel target for human NSCLC diagnosis and therapy. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

MiR-221/222 promote human glioma cell invasion and angiogenesis by targeting TIMP2.

miR-221/222 are two highly homologous microRNAs that are frequently upregulated in solid tumors. However, the effects of miR-221/222 in malignant gliomas have not been investigated thoroughly. In this study, we found that miR-221/222 were significantly upregulated in human glioma samples and glioma cell lines. Both gain- and loss-of-function studies showed that miR-221/222 regulate cell proliferation, the cell cycle and apoptosis, in addition to, invasion, metastasis, and angiogenesis in glioma cell lines. Subsequent investigations revealed that TIMP2 is a direct target of miR-221/222, and overexpression of TIMP2 reduced the miR-221/222-mediated invasion, metastasis, and angiogenesis of glioma cells. Taken together, our results suggest that the suppression of miR-221/222 may be a feasible approach for inhibiting the malignant behaviors of glioma.

Electric-field-sensitive hydrogel based on pineapple peel oxidized hydroxyethyl cellulose/gelatin/Hericium erinaceus residues chitosan and its study in curcumin delivery.

This study focused on synthesis of innovative hydrogels with electric field response from modified pineapple peel cellulose and hericium erinaceus chitosan and gelatin based on Schiff base reaction. A series of hydrogels were prepared by oxidized hydroxyethyl cellulose, gelatin and chitosan at different deacetylation degree via mild Schiff base reaction. Subsequently experiments towards the characterization of oxidized hydroxyethyl cellulose/gelatin/chitosan (OHGCS) hydrogel polymers were carried out by FTIR/XRD/XPS, swelling performances and electric response properties. The prepared hydrogels exhibited stable and reversible bending behaviors under repeated on-off switching of electric fields, affected by ionic strength, electric voltage and pH changes. The swelling ratio of OHGCS hydrogels was found reduced as deacetylation degree increasing and reached the maximum ratio âˆ¼ 2250 % for OHGCS-1. In vitro drug releasing study showed the both curcumin loading capacity and release amount of Cur-OHGCS hydrogels arrived about 90 % during 6 h. Antioxidation assessments showed that the curcumin-loaded hydrogels had good antioxidation activities, in which, 10 mg Cur-OHGCS-1 hydrogel could reach to the maximum of about 90 % DPPH scavenging ratio. These results indicate the OHGCS hydrogels have potentials in sensor and drug delivery system.

Ultrasmall Pd nanoparticles supported on a metal-organic framework DUT-67-PZDC for enhanced formic acid dehydrogenation.

The highly dispersed ultrasmall palladium nanoparticles (Pd NPs) (1.7 nm) were successfully immobilized on a N-containing metal-organic framework (MOF, DUT-67-PZDC) using a co-reduction method, and it is used as an excellent catalyst for formic acid dehydrogenation (FAD). The optimized catalyst Pd/DUT-67-PZDC(10, 10 wt% Pd loading) shows 100% hydrogen (H2) selectivity and formic acid (FA) conversion at 60 °C, and the commendable initial turnover frequency (TOF) values of 2572 h-1 with the sodium formate (SF) as an additive and 1059 h-1 even without SF, which is better than most reported MOF supported Pd monometallic heterogeneous catalysts. The activation energy (Ea) of FAD is 43.2 KJ/mol, which is lower than most heterogeneous catalysts. In addition, the optimized catalyst Pd/DUT-67-PZDC(10) maintained good stability over five consecutive runs, demonstrating only minimal decline in catalytic activity. The outstanding catalytic performance could be ascribed to the synergistic corporations of the unique structure of DUT-67-PZDC carrier with hierarchical pore characteristic, the metal-support interaction (MSI) between the active Pd NPs and DUT-67-PZDC, the highly dispersed Pd NPs with ultrafine size serve as the catalytic active site, as well as the N sites on the support could act as the proton buffers. This work provides a new paradigm for the efficient H2 production of FAD by constructing highly active heterogeneous Pd-based catalysts using MOF supports.

Pyridinic-N Regulated Electron Injection to Modulate *OH Adsorption at Fe-N-C Sites for an Efficient Oxygen Reduction Reaction.

To enhance the efficiency of oxygen reduction reaction (ORR) catalysts, precise control over the adsorption/desorption energy barriers of oxygen intermediates at atomically dispersed Fe-N-C sites is essential yet challenging. Addressing this, we employed a pyrolysis approach using a nitrogen-containing polymer to fabricate Fe single-atom (SA) catalysts embedded in a pyridinic-N enriched carbon matrix. This synthesis strategy yielded Fe SAs that demonstrated a superior electrochemical ORR performance, evidenced by an impressive half-wave potential of 0.941 V and a high limiting current density of 5.72 mA/cm2. Moreover, when applied in homemade Zn-air batteries, this premier catalyst exhibited exceptional specific capacity (720 mAh/gZn), peak power density (253 mW/cm2), and notable long-term stability. Theoretical insights revealed that the increased pyridinic-N content in the catalyst facilitated efficient electron transfer from N atoms to the Fe active sites, thus fine-tuning the d-band center and effectively controlling the adsorption energy barrier of *OH species. These mechanisms synergistically improve the ORR performance. Crucially, this fabrication method shows promise for adaptation to other transition metal-based SAs, including Co, Ni, and Cu, potentially establishing a versatile synthesis route for developing atomically dispersed catalyst systems in future applications.

Efficient hydrogen production from formic acid dehydrogenation over ultrasmall PdIr nanoparticles on amine-functionalized yolk-shell mesoporous silica.

Developing heterogeneous catalysts with exceptional catalytic activity over formic acid (HCOOH, FA) dehydrogenation is imperative to employ FA as an effective hydrogen (H2) carrier. In this work, ultrasmall (1.4 nm) and well-dispersed PdIr nanoparticles (NPs) immobilized on amine-functionalized yolk-shell mesoporous silica nanospheres (YSMSNs) with radially oriented mesoporous channels have been synthesized by a co-reduction strategy. The optimized catalyst Pd4Ir1/YSMSNs-NH2 (Pd/Ir molar ratio = 4:1) exhibited a remarkable turnover frequency (TOF) of 5818 h-1 and remarkable stability at 50 °C with the addition of sodium formate (SF), resulting in complete FA conversion and H2 selectivity, exceeding most of the solid heterogeneous catalysts in previous reports under similar circumstances. Kinetic isotope effect (KIE) exploration indicates the cleavage of the CH bond is regarded as the rate-determining step (RDS) during the FA dehydrogenation process. Such excellent catalytic properties arise from the ultrafine and well-dispersed PdIr NPs supported on the nanosphere support YSMSNs-NH2, the electronic synergistic effect of PdIr alloy NPs, and the strong metal-support interaction (MSI) effect between the introduced PdIr NPs and YSMSNs-NH2 support. This work offers a new paradigm for exploiting the highly effective silica-supported Pd-based heterogeneous catalysts over the dehydrogenation of FA.

LTBP2 down-regulated FGF2 to repress vascular smooth muscle cell proliferation and vascular remodeling in a rat model of intracranial aneurysm.

This work probed into the role of latent transforming growth factor beta binding protein 2 (LTBP2) in intracranial aneurysm (IA). The rats underwent IA modeling and then stereotactic injection of short hairpin RNA against LTBP2 (shLTBP2). Hematoxylin-eosin (HE) staining was employed to assess IA model and vascular remodeling. Rat vascular smooth muscle cells (VSMCs) were transfected with shLTBP2, LTBP2 overexpression plasmid and fibroblast growth factor 2 (FGF2) overexpression plasmid. The mRNA and protein expressions of LTBP2, FGF2 and mitochondrial apoptosis-related factors (Caspase-3, Cyt-c, Mcl-1) were tested through qRT-PCR and Western blot. Cell viability, proliferation and apoptosis were examined by cell counting kit-8, EdU assay and flow cytometry. The up-regulated LTBP2 and down-regulated FGF2 were detected in IA rats. LTBP2 knockdown promoted vascular remodeling and Mcl-1 level, and restrained cell apoptosis and expressions of Caspase-3 and Cyt-c in IA model rats. Moreover, LTBP2 knockdown potentiated cell viability, proliferation and FGF2 level, and repressed apoptosis in rat VSMCs, while overexpressed LTBP2 exerted opposite effects. FGF2 overexpression promoted proliferation and Mcl-1 level, and inhibited apoptosis and expressions of Caspase-3 and Cyt-c in rat VSMCs, which also reversed the effects of overexpressed LTBP2 on these aspects. Collectively, LTBP2 down-regulates FGF2 to repress VSMCs proliferation and vascular remodeling in an IA rat model.