Visible-Light-Photocatalyzed Self-Cyclopropanation Reactions of Dibenzoylmethanes for the Synthesis of Cyclopropanes.

A new self-cyclopropanation of 1,3-diphenylpropane-1,3-dione, leading to tetrasubstituted cyclopropane containing three contiguous stereogenic centers with high stereoselectivity, has been achieved through violet-light-emitting diode-irradiated photocatalysis, featuring both cycloaddition and a distinctive rearrangement. Diverging from conventional cyclopropanation pathways, this reaction yields a tetrasubstituted cyclopropane through unprecedented rearrangement and cascade reactions.

Interaction among dietary n-3 and n-6 polyunsaturated fatty acid intake, fatty acid desaturase 2 genetic variants, and low-density lipoprotein cholesterol levels in type 2 diabetes patients.

AIMS/INTRODUCTION: Fatty acid desaturase (FADS) genetic polymorphisms are strongly correlated with the risk of dyslipidemia and cardiovascular disease. In this study, we examined the impact of FADS1 and FADS2 genetic variants on plasma lipid status, and assessed interactions between FADS genetic polymorphisms and plasma n-3/n-6 fatty acids regarding lipid status within a population of 816 Taiwanese patients with type 2 diabetes. MATERIALS AND METHODS: Selected tag single-nucleotide polymorphisms (FADS1 rs174546 [T/C]; FADS2 rs174602 [A/G] and rs2072114 [A/G]) were genotyped (n = 816). RESULTS: The distribution of genotypes were compared with reports publicly available in the Genome Aggregation Database for East Asian populations (https://gnomad.broadinstitute.org). In the subgroup of patients not taking lipid-lowering medications (n = 192), we observed that the G allele of FADS2 rs174602 was statistically significantly correlated with lower low-density lipoprotein cholesterol (LDL-C) concentrations (P = 0.001), whereas the G allele of rs2072114 was marginally associated with LDL-C concentrations (P = 0.091). Using a general linear model adjusted for confounding factors, statistically significant interactions (P = 0.016) between single-nucleotide polymorphisms in rs2072114 and a low alpha-linolenic acid (18:3n-3)/linoleic acid (18:2n-6) ratio; the G allele correlated with lower LDL-C levels among individuals with a low alpha-linolenic acid/linoleic acid ratio. Interaction between rs174602 single-nucleotide polymorphisms and low alpha-linolenic acid/linoleic acid values on LDL-C was only marginally significant (P = 0.063). CONCLUSIONS: Our results show the role of n-3/n-6 dietary polyunsaturated fatty acids in modifying the effects of genetic susceptibility on lipoprotein concentrations in patients with type 2 diabetes. Our findings highlight the potential of interventions with dietary polyunsaturated fatty acids regarding developing individualized prevention strategies for type 2 diabetes presenting with co-occurring dyslipidemia and cardiovascular diseases.

Structural basis for the helical filament formation of Escherichia coli glutamine synthetase.

Escherichia coli glutamine synthetase (EcGS) spontaneously forms a dodecamer that catalytically converts glutamate to glutamine. EcGS stacks with other dodecamers to create a filament-like polymer visible under transmission electron microscopy. Filamentous EcGS is induced by environmental metal ions. We used cryo-electron microscopy (cryo-EM) to decipher the structure of metal ion (nickel)-induced EcGS helical filament at a sub-3Å resolution. EcGS filament formation involves stacking of native dodecamers by chelating nickel ions to residues His5 and His13 in the first N-terminal helix (H1). His5 and His13 from paired parallel H1 helices provide salt bridges and hydrogen bonds to tightly stack two dodecamers. One subunit of the EcGS filament hosts two nickel ions, whereas the dodecameric interface and the ATP/Mg-binding site both host a nickel ion each. We reveal that upon adding glutamate or ATP for catalytic reactions, nickel-induced EcGS filament reverts to individual dodecamers. Such tunable filament formation is often associated with stress responses. Our results provide detailed structural information on the mechanism underlying reversible and tunable EcGS filament formation.

DLWIoT: Deep Learning-based Watermarking for Authorized IoT Onboarding.

The onboarding of IoT devices by authorized users constitutes both a challenge and a necessity in a world, where the number of IoT devices and the tampering attacks against them continuously increase. Commonly used onboarding techniques today include the use of QR codes, pin codes, or serial numbers. These techniques typically do not protect against unauthorized device access-a QR code is physically printed on the device, while a pin code may be included in the device packaging. As a result, any entity that has physical access to a device can onboard it onto their network and, potentially, tamper it (e.g., install malware on the device). To address this problem, in this paper, we present a framework, called Deep Learning-based Watermarking for authorized IoT onboarding (DLWIoT), featuring a robust and fully automated image watermarking scheme based on deep neural networks. DLWIoT embeds user credentials into carrier images (e.g., QR codes printed on IoT devices), thus enables IoT onboarding only by authorized users. Our experimental results demonstrate the feasibility of DLWIoT, indicating that authorized users can onboard IoT devices with DLWIoT within 2.5-3sec.

The Repository Chemotion: Infrastructure for Sustainable Research in Chemistry*.

The repository Chemotion provides solutions for current challenges to store research data in a feasible manner. A main advantage of Chemotion is the comprehensive functionality, offering options to collect, prepare, and reuse data with discipline-specific methods and data-processing tools.

In Vitro and In Vivo Studies of Hydrophilic Electrospun PLA95/ß-TCP Membranes for Guided Tissue Regeneration (GTR) Applications.

The guided tissue regeneration (GTR) membrane is a barrier intended to maintain a space for alveolar bone and periodontal ligament tissue regeneration but prevent the migration of fast-growing soft tissue into the defect sites. This study evaluated the physical properties, in vivo animal study, and clinical efficacy of hydrophilic PLA95/ß-TCP GTR membranes prepared by electrospinning (ES). The morphology and cytotoxicity of ES PLA95/ß-TCP membranes were evaluated by SEM and 3-(4,5-cimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) respectively. The cementum and bone height were measured by an animal study at 8 and 16 weeks after surgery. Fifteen periodontal patients were selected for the clinical trial by using a commercial product and the ES PLA95/ß-TCP membrane. Radiographs and various indexes were measured six months before and after surgery. The average fiber diameter for this ES PLA95/ß-TCP membrane was 2.37 ± 0.86 µm. The MTT result for the ES PLA95/ß-TCP membrane showed negative for cytotoxicity. The significant differences in the cementum and bone height were observed between empty control and the ES PLA95/ß-TCP membrane in the animal model (p < 0.05). Clinical trial results showed clinical attachment level (CAL) of both control and ES PLA95/ß-TCP groups, with a significant difference from the pre-surgery results after six months. This study demonstrated that the ES PLA95/ß-TCP membrane can be used as an alternative GTR membrane for clinical applications.

In Vitro Evaluation of Dentin Tubule Occlusion for Novel Calcium Lactate Phosphate (CLP) Paste.

INTRODUCTION: The objective of this in vitro study is to evaluate the effective and long-term occlusion of dentinal tubules using a novel calcium lactate phosphate (CLP) based desensitizing agent. METHODS: Dentin disks (n = 9) were pre-etched using 1 M lactic acid for 30 s and individually treated with Colgate® Pro-Relief™ paste, CLP paste, and double distilled water (ddH2O) by a rubber-cupped handpiece. Dentin disks were analyzed under optical micrographs for pre-treatment, directly after treatment, and 14 days post-treatment. One-way ANOVA and post-hoc Tukey's test were used to determine whether there were any statistically significant differences in dentinal tubule diameter. RESULTS: A significant decrease occurred in the mean tubule diameter for dentin disks treated with CLP paste. A decrease was observed from 3.52 ± 0.83 µm to 2.62 ± 0.42 µm right after treatment, further decreasing to 1.71 ± 0.45 µm after immersion in artificial saliva for 14 days (p < 0.05). CONCLUSIONS: The results suggest that the CLP based desensitizing paste has remineralization properties and provides instant and lasting effectiveness in dentinal tubule occlusion.

Disease Characteristics and Electromyographic Findings of Nonsurgery-Related Unilateral Vocal Fold Paralysis.

OBJECTIVE: The detailed characteristics and prognosis of nonsurgery-related unilateral vocal fold paralysis (NSUVFP) are currently unclear. This study evaluated the extent of laryngeal nerve lesions and the individual characteristics for patients with NSUVFP. STUDY DESIGN: Retrospective, case series. METHODS: Patients with unilateral vocal fold paralysis (UVFP) were evaluated using videolaryngostroboscopy and quantitative laryngeal electromyography. The side of nerve lesions, involvement of the external branch of the superior laryngeal nerve (eSLN), and complete vocal fold motion recovery were evaluated after ≥ 6 month follow-up. RESULTS: A total of 207 UVFP patients were recruited, including 153 surgery-related UVFP and 54 NSUVFP patients. Thirty-four (63%) and 20 (37%) NSUVFP patients were further assigned to idiopathic and nonsurgery-related-nonidiopathic (NSNI) groups, respectively. In the idiopathic group, eSLN lesions occurred in all six (100%) patients with right-side paralysis, but in only six of 28 (21%) patients with left-side paralysis (P < 0.001). The turn frequency of the paralyzed thyroarytenoid-lateral cricoarytenoid muscle complex is lower in the NSNI group (333.1 ± 192.1) compared with the idiopathic group (490.2 ± 255.1) (P = 0.02). The probability of complete vocal fold motion recovery did not differ among groups (P > 0.05). CONCLUSION: Idiopathic and NSNI UVFP have different clinical presentations defined by laryngeal electromyography. NSNI UVFP had more severe denervation changes compared with idiopathic UVFP. These results may support two pathogenic mechanisms for idiopathic UVFP: 1) neuropathy specifically involving left recurrent laryngeal nerve (RLN), and 2) neuropathy affecting nerves proximal to the RLN. LEVEL OF EVIDENCE: 4. Laryngoscope, 127:1381-1387, 2017.

The effect of propofol and sevoflurane on antioxidants and proinflammatory cytokines in a porcine ischemia-reperfusion model.

OBJECTIVES: Ischemia-reperfusion (IR) features massive oxidative stress of tissues and cytokine response. Propofol and sevoflurane, both of which are commonly used anesthetics, are thought to have different antioxidant activities. The aim of this study is to delineate the influence of these two drugs on the production of free radicals and proinflammatory cytokines in IR conditions via in vitro and in vivo models. METHODS: An in vitro IR model was performed by incubating porcine cells (including mononuclear cells, and coronary and aortic smooth muscle cells) with either propofol 25 µM or sevoflurane 2% in the hypoxia chamber (1% O2, 37°C) for 1 hour, followed by room temperature air for 2 hours. Reactive oxygen species (ROS) and tumor necrosis factor-α (TNF-α) were also measured via flow cytometry and enzyme-linked immunosorbent assay methods, respectively. Ten pigs were used for the in vivo study. After anesthesia with either propofol (10-15 mg/kg/h) or sevoflurane (2%), internal carotid and femoral arterial catheters were inserted for direct blood pressure monitoring and blood sampling. The IR models were produced via descending thoracic aorta clamping for 1 hour and declamping for 2 hours during the procedure for left ventricular assist device implantation. Blood serum was sampled from upper and lower body vessels for ROS and TNF-α evaluation via thiobarbituric acid reacting substances method and enzyme-linked immunosorbent assay, respectively. RESULTS: The results showed significant reduction of both ROS and TNF-α levels in the propofol group in vitro IR model. However, there was no difference in lipid peroxidation and TNF-α level between propofol and sevoflurane for the in vivo IR model. CONCLUSION: We concluded that propofol, compared with sevoflurane, can significantly inhibit ROS formation on a cell level. In addition, propofol can significantly inhibit TNF-α formation of monocytes and coronary smooth muscle cells but not aortic smooth muscle cells.

Generation of bright isolated attosecond soft X-ray pulses driven by multicycle midinfrared lasers.

High harmonic generation driven by femtosecond lasers makes it possible to capture the fastest dynamics in molecules and materials. However, to date the shortest subfemtosecond (attosecond, 10(-18) s) pulses have been produced only in the extreme UV region of the spectrum below 100 eV, which limits the range of materials and molecular systems that can be explored. Here we experimentally demonstrate a remarkable convergence of physics: when midinfrared lasers are used to drive high harmonic generation, the conditions for optimal bright, soft X-ray generation naturally coincide with the generation of isolated attosecond pulses. The temporal window over which phase matching occurs shrinks rapidly with increasing driving laser wavelength, to the extent that bright isolated attosecond pulses are the norm for 2-µm driving lasers. Harnessing this realization, we experimentally demonstrate the generation of isolated soft X-ray attosecond pulses at photon energies up to 180 eV for the first time, to our knowledge, with a transform limit of 35 attoseconds (as), and a predicted linear chirp of 300 as. Most surprisingly, advanced theory shows that in contrast with as pulse generation in the extreme UV, long-duration, 10-cycle, driving laser pulses are required to generate isolated soft X-ray bursts efficiently, to mitigate group velocity walk-off between the laser and the X-ray fields that otherwise limit the conversion efficiency. Our work demonstrates a clear and straightforward approach for robustly generating bright isolated attosecond pulses of electromagnetic radiation throughout the soft X-ray region of the spectrum.

EMLA and water immersion cause similar vasodilatation in replanted fingers.

BACKGROUND: Skin wrinkling on water immersion is a reliable and simple test of sympathetic innervation. The eutectic mixture of local anesthetic (EMLA) cream has been shown to induce near identical clinical wrinkling scores and reduction in digit blood flow as that following water immersion in people with normal sympathetic innervation. This study was designed to investigate the vasomotor response to EMLA in replanted fingers that had poor sympathetic innervation. METHODS: Laser Doppler imaging (PeriScan PIM II; Perimed AB, Stockholm, Sweden) was used to detect perfusion changes in the pulps of fourteen replanted fingers before and after 0.5 g of 5% EMLA cream application and water immersion in a 40 degrees C normal saline for 30 min, respectively. Comparisons were made with the contralateral corresponding normal fingers. RESULTS: After water immersion and EMLA application, all of the normal fingers showed a considerable and similar decrease in blood perfusion that demonstrated in the absolute perfusion units (pU) (baseline: 1.57 +/- 0.33 pU, after water-immersion, 1.19 +/- 0.22 pU, P < 0.001; decrease: 23.6 +/- 7.7%, after EMLA application: 1.20 +/- 0.18 pU, P < 0.001; decrease: 22.4 +/- 8.9%). In contrast, all of the replanted fingers showed a statistically significant vasodilatatory response (baseline: 1.20 +/- 0.29 pU, after water-immersion: 1.36 +/- 0.28 pU, P < 0.001; increase: 15.2 +/- 9.1%, after EMLA application: 1.38 +/- 0.27 pU, P < 0.001; increase: 16.8 +/- 9.1%). CONCLUSIONS: EMLA and water immersion both cause vasodilatation and no skin wrinkling in replanted fingers. These results imply that intact sympathetic nerve function is required to induce the vasoconstrictive effect of EMLA.