Facile synthesis of Cd-substituted zeolitic-imidazolate framework Cd-ZIF-8 and mixed-metal CdZn-ZIF-8

scientific paperZeolitic-imidazole framework ZIF-8 has attracted tremendous interests for the highresolution kinetic separation of propylene/propane mixture due to its effective aperture size in between the sizes of propylene and propane molecules. It is of great interest to fine-tune the effective aperture size of ZIF-8 either to improve its propylene/propane separation performances or to extend its use to the separation of other gas mixtures. It has been shown that substituting Zn with other metal nodes (e.g. Co) is a potential means to fine-tune the effective aperture size of ZIF-8. Here, we attempt to introduce another metal center, Cd, into ZIF-8 in a facile and scalable manner. Phase-pure Cd-ZIF-8 was successfully synthesized in methanol using a conventional solvothermal method, although it showed a narrow synthesis window. The presence of an organic base (triethylamine, TEA) was found critical not only for the facile synthesis of phase-pure Cd- ZIF-8 but also for the suppression of its phase transformation. A battery of characterizations including single-crystal X-ray structure solutions confirmed that the effective aperture size of Cd-ZIF-8 is the largest among its iso-structures (Zn-ZIF-8 and Co-ZIF-8). Finally, for the first time, mixed-metal CdZn-ZIF-8 crystals with various Cd/Zn ratios were solvothermally synthesized, demonstrating a further opportunity for varying the effective aperture sizes of ZIF-8 and its iso-structures.National Science Foundation Qatar National Research Fund Texas A&M Engineering Experimental Station

Risk factors for blood transfusion after Cesarean section in patients with partial placenta previa

This study assessed risk factors for blood transfusion after Cesarean section in patients with partial placenta previa. We retrospectively reviewed the medical records of 149 patients who underwent Cesarean sections for partial placenta previa between January 2010 and October 2021. Clinical characteristics were compared between the two groups: the blood transfusion group (n=22), defined as patients who received a blood transfusion during surgery or within 24 hours after surgery, and the non-blood transfusion group (n=127), which included other patients. Multivariable logistic regression analysis identified two risk factors independently associated with blood transfusion: antenatal hemorrhage (adjusted odds ratio [aOR], 16.283; 95% confidence interval [CI], 4.405-60.190; P<0.001) and preoperative hemoglobin (g/dL) (aOR, 0.427; 95% CI, 0.246-0.739; P=0.002). Thus, patients who are at risk for these two factors should be carefully managed with sufficient preparation for blood transfusion and anesthetic management

Transcriptional Regulator TonEBP Mediates Oxidative Damages in Ischemic Kidney Injury

TonEBP (tonicity-responsive enhancer binding protein) is a transcriptional regulator whose expression is elevated in response to various forms of stress including hyperglycemia, inflammation, and hypoxia. Here we investigated the role of TonEBP in acute kidney injury (AKI) using a line of TonEBP haplo-deficient mice subjected to bilateral renal ischemia followed by reperfusion (I/R). In the TonEBP haplo-deficient animals, induction of TonEBP, oxidative stress, inflammation, cell death, and functional injury in the kidney in response to I/R were all reduced. Analyses of renal transcriptome revealed that genes in several cellular pathways including peroxisome and mitochondrial inner membrane were suppressed in response to I/R, and the suppression was relieved in the TonEBP deficiency. Production of reactive oxygen species (ROS) and the cellular injury was reproduced in a renal epithelial cell line in response to hypoxia, ATP depletion, or hydrogen peroxide. The knockdown of TonEBP reduced ROS production and cellular injury in correlation with increased expression of the suppressed genes. The cellular injury was also blocked by inhibitors of necrosis. These results demonstrate that ischemic insult suppresses many genes involved in cellular metabolism leading to local oxidative stress by way of TonEBP induction. Thus, TonEBP is a promising target to prevent AKI

Influence of Friction Stir Welding on Mechanical Properties of Butt Joints of AZ61 Magnesium Alloy

In this study, the effect of heat input on the mechanical properties and fracture behaviors of AZ61 magnesium alloy joints has been studied. Magnesium alloy AZ61 plates with thickness of 5 mm were welded at different ratios of tool rotational speed to welding speed (ω/ν). The average ultimate tensile strength of all weld conditions satisfying a ω/ν ratio of 3 reached 100% of the strength of the base material. Fractures occurred at the interface between the thermomechanical affected zone at advancing side and the stir zone in all welded specimens. From the scanning electron microscope and electron backscatter diffraction analysis, it was determined that the interface between the thermomechanical affected zone and the stir zone, which is the region where the grain orientation changes, was the weakest part; the advancing side region was relatively weaker than the retreating side region because the grain orientation change occurred more dramatically in the advancing side region

Effect of the glyceryl monooleate-based lyotropic phases on skin permeation using in vitro diffusion and skin imaging

AbstractGlyceryl monooleate (GMO) is a polar lipid that can exist in various liquid crystalline phases in the presence of different amounts of water. It is regarded as a permeation enhancer due to its amphiphilic property. Various phases of GMO/solvent system containing sodium fluorescein were prepared to compare permeability using confocal laser scanning microscopy (CLSM). GMO was melted in a vial in a water bath heated to 45 °C. Propylene glycol and hexanediol were homogeneously dissolved in the melted GMO. Sodium fluorescein in aqueous solution was diluted to various ratios and thoroughly mixed by an ultrasonic homogenizer. Each GMO/Solvent system with fluorescein was applied onto the epidermal side of excised pig skin and incubated overnight. CLSM was performed to observe how the GMO/solvent system in its different phases affect skin permeability. Cubic and lamellar phase formulations enhanced the fluorescein permeation through the stratum corneum. A solution system had the weakest permeability compared to the other two phases. Due to the amphiphilic nature of GMO, cubic and lamellar phases might reduce the barrier function of stratum corneum which was observed by CLSM as fluorescein accumulated in the dermis. Based on the results, the glyceryl monooleate lyotropic mixtures could be applied to enhance skin permeation in various topical and transdermal formulations

Potential pharmacological chaperones targeting cancer-associated MCL-1 and Parkinson disease-associated α-synuclein

Pharmacological chaperones are small molecules that bind to proteins and stabilize them against thermal denaturation or proteolytic degradation, as well as assist or prevent certain protein-protein assemblies. These activities are being exploited for the development of treatments for diseases caused by protein instability and/or aberrant protein-protein interactions, such as those found in certain forms of cancers and neurodegenerative diseases. However, designing or discovering pharmacological chaperones for specific targets is challenging because of the relatively featureless protein target surfaces, the lack of suitable chemical libraries, and the shortage of efficient high-throughput screening methods. In this study, we attempted to address all these challenges by synthesizing a diverse library of small molecules that mimic protein α-helical secondary structures commonly found in protein-protein interaction surfaces. This was accompanied by establishing a facile "on-bead" high-throughput screening method that allows for rapid and efficient discovery of potential pharmacological chaperones and for identifying novel chaperones/inhibitors against a cancer-associated protein, myeloid cell leukemia 1 (MCL-1), and a Parkinson disease-associated protein, α-synuclein. Our data suggest that the compounds and methods described here will be useful tools for the development of pharmaceuticals for complex-disease targets that are traditionally deemed "undruggable.

The Korean Bird Information System (KBIS) through open and public participation

<p>Abstract</p> <p>Background</p> <p>The importance of biodiversity conservation has been increasing steadily due to its benefits to human beings. Recently, producing and managing biodiversity databases have become much easier because of the information technology (IT) advancement. This made the general public's participation in biodiversity conservation much more practical than ever. For example, an openfree web service can be devised for a wider spectrum of people to collaborate with each other for sharing biodiversity information. Bird migration is one such area of the collaboration. Korean migratory birds are usually traceable in the important routes of the East Asian-Australia Flyway (EAAF), and they play a key role as an environmental change indicator of the Earth. Therefore, the preservation of migratory birds requires an information system which involves a broader range of voluntary and interactive knowledge network to process bird information production, circulation, and dissemination.</p> <p>Results</p> <p>The Korean Bird Information System (KBIS) aims to construct a cooperative partnership domestically and internationally through the acquisition, management, and sharing of Korean bird information involving both expert and non-expert groups. KBIS has six goals: data standard, system linkage, data diversity, utilization, bird knowledge network, and statistics. The key features of KBIS are to provide a simple search, gallery (photographs), and community to lead the participation of numerous non-experts, especially amateur bird watchers. The function of real-time observation data submission through the internet has been accomplished. It also provides bird banding database, statistics, and taxon network for experts. Especially, the statistics part provides the user with easy understanding of ecological trends of species based on the time and region.</p> <p>Conclusion</p> <p>KBIS is a tool for the conservation and management of bird diversity and ecosystem that encourages users to participate by providing the openfree data access and real-time data input web-interface. It will enhance bird knowledge networking activities locally, nationally, and internationally. In addition, it provides opportunities to enhance the public awareness for the preservation of bird diversity and species information in relevant localities through the database construction and networking activities. It can be found at <url>http://korbird.naris.go.kr</url>.</p