Acral Pigmentation in Peutz-Jeghers Syndrome: Dermoscopic Findings and Treatment with the Q-Switched Nd:YAG Laser.

Peutz-Jeghers syndrome (PJS; MIM 175200) is an autosomal dominant multiple-organ cancer syndrome. It is characterized by brown macules distributed in the perioral skin, oral mucosa, hands and feet, and hamartomatous gastrointestinal polyps that can eventually lead to intestinal obstruction, abdominal pain, bleeding, and anemia. Patients with PJS are at a higher risk of ovarian, testicular, breast, lung, and pancreatic cancers. This predisposition is due to the pathogenic variant in serine/threonine kinase 11 (STK11) gene located on chromosome 19p13.3. Here, we present the dermoscopic findings, histopathologic features of acral pigmentation, and DNA sequencing results of the patient with PJS. We also report a successful removal of acral pigmentation using the Q-switched Nd:YAG laser (QSNYL) treatment. Our results suggest that QSNYL therapy could be a treatment option for acral pigmentation in patients with PJS.

Dissipation and Residue Pattern of Dinotefuran, Fluazinam, Indoxacarb, and Thiacloprid in Fresh and Processed Persimmon Using LC-MS/MS.

Pesticides which are diluted and sprayed according to the pre-harvest interval (PHI) are generally decomposed and lost through various factors and pathways, and the leftover pesticides are known as residual pesticides. This study aims to determine the dissipation of residual amounts of dinotefuran, fluazinam, indoxacarb, and thiacloprid in persimmon and the changes in the concentration of various processing products. Pesticide spraying is performed in accordance with the GAP (good agricultue practice) of Korea, and the processed products are manufactured using a conventional method after removing the skin of persimmons. The modified QuEchERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method and an optimized method using LC-MS/MS (liquid chromatography mass spectrometry) is implemented to analyze the residual pesticides. The linearity, recovery, and LOQ (limit of quantitation) are presented to verify the analysis method. The amount of residual pesticides tested decreases significantly in a time-dependent manner, regardless of the minimal dilution effect present due to growth. The residual concentration does not vary significantly during the processing stage despite the removal of the systemic pesticides, dinotefuran and thiacloprid. The residues of non-systemic pesticides, fluazinam and indoxacarb, are typically removed by the peeling removal and processing methods. The reduction factor of dinotefuran, whose residual concentration is increased, is less than 1, and the absolute amount of pesticides is decreased through processing. The results of this study can be used as the scientific basis data to ensure the safety of residual pesticides in processed products in the future.

Metal-Mediated Morphology Regulation of Self-Assembled Double-Hydrophilic Block Copolymers.

We report a nanoscale morphology-regulation strategy of self-assembled double-hydrophilic block copolymers with square planar PtII compounds. The selective coordination of PtII on the chelating blocks of poly(acrylic acid)-b-poly(ethylene glycol) (PAA-b-PEG) induced the self-association of metal-chelated unimers by the known cohesive force of PtII. The block-length variation of PAA with constant PEG led to the shape transition from normal core/shell and crew-cut spheres to anisotropic pearl-string structures. On the other hand, PtII adsorption on PEG blocks by extensive hydrogen bonding can further modify the molecular geometry of metal-chelated unimers by decreasing the volume of hydrophilic segments, eventually leading to the shape transition to vesicular structures. This result was well correlated to the structural constraint of PEG conformation estimated by the quantitative 1H NMR analysis. The vesicles also exhibited the enclosing nature for the fluorescent guest molecules, which demonstrated the promising potential for the encapsulating delivery vehicle.

Construction of Paramagnetic Manganese-Chelated Polymeric Nanoparticles Using Pyrene-End-Modified Double-Hydrophilic Block Copolymers for Enhanced Magnetic Resonance Relaxivity: A Comparative Study with Cisplatin Pharmacophore.

Cationic metal-mediated self-assembly of double-hydrophilic block copolymers (DHBCs) has been of great interest for the preparation of hybrid nanoparticles for versatile applications. Among many functional transition-metal ions, manganese (MnII) is a highly attractive element due to its paramagnetic property with a high coordination number. However, MnII does not lead to the efficient self-assembly of DHBCs because of the relatively high aqueous solubility of coordinated MnII. This article reports a facile method for direct conjugation of MnII ions inside sterically stabilized polymer assemblies, composed of pyrene-end-modified DHBCs. Nitroxide-mediated radical polymerization was used to prepare the poly(ethylene glycol)- b-poly(acrylate) DHBC precursor, followed by the end-modification with pyrene maleimide via the radical-exchange reaction. Employing the self-associated DHBC as the nanoscale template, the simple addition of MnII enables a large number of polyvalent MnII ions to be immobilized at the chelating blocks of DHBCs, which can be readily monitored by the excimeric fluorescence emission change of the terminal pyrene fluorophore. The resulting MnII-loaded polymeric nanoparticles (MnII-PNPs) possess nanogel-like scaffolds, which allow for efficient water permeation at the MnII-incorporated interior for enhanced magnetic resonance contrasting effect. Additionally, by comparing the coordination properties of MnII and cisplatin, we endeavor to understand the internal structures and the relevant physicochemical features of metal-chelated nanoparticles.

Cisplatin-Encapsulated Polymeric Nanoparticles with Molecular Geometry-Regulated Colloidal Properties and Controlled Drug Release.

Encapsulation of chemotherapeutic agents inside a nanoscale delivery platform can provide an attractive therapeutic strategy with many pharmaceutical benefits, such as increased plasma solubility, prolonged in vivo circulation, and reduced acute toxicity. Given that the biological activities of polymeric nanoparticles are highly dependent on their colloidal structures, the molecular geometry-regulated programming of self-assembled nanoscale architecture is of great interest for chemical design of an ideal delivery platform. In this report, we demonstrate that the molecular geometry of block-copolymer excipients can govern the level of drug-loading capacity and core hydrophobicity of polymeric nanoparticles, which can eventually control the pH-sensitive drug-release property. Atom-transfer radical polymerization was employed as a controlled synthetic method for the copolymer excipients, which contain the metal-chelating poly(acrylic acid) block linked to either a small mPEG-grafted poly(methacrylate) to generate a bulky brush-like chains or a simple linear mPEG segment. During the coordination of cis-diammineplatinum(II) as an active pharmacophore of cisplatin, aqueous-phase size-exclusion chromatography analyses exhibited highly different self-association kinetic regimes prompted by versatile molecular geometry of copolymer excipients, which further allows us to explore the molecular geometry-colloidal property relationship.

A Low Temperature, Solution-Processed Poly(4-vinylphenol), YO(x) Nanoparticle Composite/Polysilazane Bi-Layer Gate Insulator for ZnO Thin Film Transistor.

Low temperature, solution-processed metal oxide thin film transistors (MEOTFTs) have been widely investigated for application in low-cost, transparent, and flexible electronics. To enlarge the application area, solution-processed gate insulators (GI) have been investigated in recent years. We investigated the effects of the organic/inorganic bi-layer GI to ZnO thin film transistors (TFTs). PVP, YO(x) nanoparticle composite, and polysilazane bi-layer showed low leakage current (-10(-8) A/cm2 in 2 MV), which are applicable in low temperature processed MEOTFTs. Polysilazane was used as an interlayer between ZnO and PVP, YO(x) nanoparticle composite as a good charge transport interface with ZnO. By applying the PVP, YO(x), nanoparticle composite/polysilazane bi-layer structure to ZnO TFTs, we successfully suppressed the off current (I(off)) to -10(-11) and fabricated good MEOTFTs in 180 degrees C.

Fluorinated CYTOP passivation effects on the electrical reliability of multilayer MoS2 field-effect transistors.

We demonstrated highly stable multilayer molybdenum disulfide (MoS2) field-effect transistors (FETs) with negligible hysteresis gap (ΔV(HYS) ∼ 0.15 V) via a multiple annealing scheme, followed by systematic investigation for long-term air stability with time (∼50 days) of MoS2 FETs with (or without) CYTOP encapsulation. The extracted lifetime of the device with CYTOP passivation in air was dramatically improved from 7 to 377 days, and even for the short-term bias stability, the experimental threshold voltage shift, outstandingly well-matched with the stretched exponential function, indicates that the device without passivation has approximately 25% larger the barrier distribution (ΔE(B) = k(B)T(o)) than that of a device with passivation. This work suggests that CYTOP encapsulation can be an efficient method to isolate external gas (O2 and H2O) effects on the electrical performance of FETs, especially with low-dimensional active materials like MoS2.

Improved photovoltaic performance of inverted polymer solar cells through a sol-gel processed Al-doped ZnO electron extraction layer.

We demonstrate that nanocrystalline Al-doped zinc oxide (n-AZO) thin film used as an electron-extraction layer can significantly enhance the performance of inverted polymer solar cells based on the bulk heterojunction of poly[[9-(1-octylnonyl)-9H-carbazole-2,7-diyl]-2,5-thiophenediyl-2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl] (PCDTBT) and [6,6]-phenyl C(71)-butyric acid methyl ester (PC(70)BM). A synergistic study with both simulation and experiment on n-AZO was carried out to offer a rational guidance for the efficiency improvement. As a result, An n-AZO film with an average grain size of 13 to 22 nm was prepared by a sol-gel spin-coating method, and a minimum resistivity of 2.1 × 10(-3) Ω·cm was obtained for an Al-doping concentration of 5.83 at.%. When an n-AZO film with a 5.83 at.% Al concentration was inserted between the ITO electrode and the active layer (PCDTBT:PC(70)BM), the power conversion efficiency increased from 3.7 to 5.6%.

High-efficiency inverted organic solar cells with polyethylene oxide-modified Zn-doped TiO2 as an interfacial electron transport layer.

High efficiency inverted organic solar cells are fabricated using the PTB7:PC71BM polymer by incorporating Zn-doped TiO2 (ZTO) and 0.05 wt% PEO:ZTO as interfacial electron transport layers. The 0.05 wt% PEO-modified ZTO device shows a significantly increased power conversion efficiency (PCE) of 8.10%, compared to that of the ZTO (7.67%) device.