Hydrophobicity of the Pentafluorosulfanyl Group in Side Chains of Polymethacrylates by Evaluation with Surface Free Energy and Neutron Reflectivity.

A hydrophobic surface or coating is required for surface protection, anti-fouling, adhesion, and other applications. For the achievements of hydrophobic properties, fluorine-based coatings, such as the introduction of trifluoromethyl or difluoromethylene groups, are conventionally employed. Recent developments in synthetic chemistry have indicated other organic fluoroalkyl groups that are suitable for achieving a more hydrophobic surface. In this study, we focused on the hydrophobic properties of the pentafluorosulfanyl (-SF5) group. We synthesized polymethacrylates with -SF5 groups or other functional groups (-CF3, -CH3, and -H) in their side chains and evaluated their hydrophobicity based on contact angles of water and ethylene glycol and the affinities of their films to water through neutron reflectivity measurements to demonstrate the superior hydrophobic properties of the -SF5 group. The water contact angle on the polymethacrylate film with -SF5 groups was larger, which suggested that the surface free energy was lower than that of the other polymethacrylate thin films with pendant side chains of -CF3, -CH3, and -H. In addition, the fitting analyses of the neutron reflectivity profiles of the thin polymer films in contact with air and water revealed the lowest affinity between water and the surface of polymethacrylate films with -SF5 groups among the films of the synthesized polymers. Thus, we demonstrated the potential of pentafluorosulfanyl groups as advanced hydrophobic groups.

Preparation of Tenuifolin from Polygala senega L. Root Using a Hydrolytic Continuous Flow System under High-Temperature, High-Pressure Conditions.

An improved process for preparing tenuifolin (presenegenin 3-ß-d-glucopyranoside) from the root of Polygala senega L. was developed. A crude saponin mixture extracted from P. senega was subjected to hydrolysis, and the reactivity of compounds in the extract was controlled by utilizing the combination of a flow reactor and experimental design. In addition, column chromatography with HP 20, a synthetic polystyrenic adsorbent, allowed the gram-scale preparation of tenuifolin in a continuous manner with fewer steps. This approach shortens the total time required for gram-scale preparation from 16 to 5 h in a continuous manner while improving the yield from 0.59% to 2.08% (w/w).

Direct oral anticoagulants increase bleeding risk after endoscopic sphincterotomy: a retrospective study.

BACKGROUND: Bleeding can be a serious adverse event of endoscopic sphincterotomy (EST). However, the risk of EST bleeding between direct oral anticoagulant (DOAC) users and those who received no antithrombotic agents has not been clarified. This study analyzed the risk factors for bleeding after EST in patients on DOAC and evaluated the Japan Gastroenterological Endoscopy Society (JGES) guidelines for gastroenterological endoscopy in patients undergoing antithrombotic treatment. METHODS: We retrospectively analyzed 524 patients treated with EST who received DOAC or no antithrombotic drug from May 2016 to August 2019. We investigated the risk factors for bleeding. DOAC was typically discontinued for ≤ 1-day based on the JGES guideline. Although DOAC therapy recommenced the next morning after EST in principle, the duration of DOAC cessation and heparin replacement were determined by the attending physician based on each patient's status. RESULTS: The number of patients on DOAC (DOAC group) and those not on antithrombotic drug (no-drug group) was 42 (8.0%) and 482 (92.0%), respectively. DOAC was discontinued for ≤ 1-day in 17 (40.0%) patients and for > 1-day in 25 (60.0%). Of the 524 patients, 21 (4.0%) had EST bleeding. The bleeding rate was higher in the DOAC group (14.0%) (p = 0.004). Multivariate analysis showed that bleeding occurred more frequently in patients on DOAC (odds ratio [OR] 3.95, 95% confidence interval [CI] 1.37-11.4, p = 0.011), patients with low platelet counts (< 100,000/µl) (OR 6.74, 95% CI 2.1-21.6, p = 0.001), and elderly patients (> 80 years old) (OR 3.36, 95%CI 1.17-9.65, p = 0.024). CONCLUSIONS: DOAC treatment, low platelet count, and old age (> 80 years old) are risk factors for EST bleeding. Although the bleeding incidence increased in patients on DOAC who received antithrombotic therapy according to the JGES guidelines, successful hemostasis was achieved with endoscopy in all cases, and no thrombotic events occurred after cessation of DOAC. Thus, the JGES guidelines are acceptable.

Clinical and endoscopic features of aorto-duodenal fistula resulting in its definitive diagnosis: an observational study.

BACKGROUND: Upper gastrointestinal (GI) bleeding is the most important presentation of an aorto-duodenal fistula (ADF). Early diagnosis is difficult, and the disease is associated with high mortality. The present study aimed to examine the clinical and the endoscopic characteristics of ADF in eight patients who presented to our hospital. We also sought to clarify the diagnostic approach towards the disease. METHODS: The present study examined the clinical and the endoscopic/computed tomography (CT) characteristics of ADF in eight patients who were definitively diagnosed with this condition in a 12-year period at our hospital. RESULTS: The patients comprised of five men and three women, with a mean age of 69.8 years. Upper gastrointestinal bleeding was the chief complaint for all the patients. Out of these, two patients presented with shock. The patients' mean haemoglobin at presentation was 7.09 g/dL, and the mean number of blood transfusions was 7.5. All patients had undergone intervention to manage an aortic pathology in the past. As the first investigation, an upper GI endoscopy in 5 and a CT scan in 3 patients were performed. In cases where CT scan was performed first, no definitive diagnosis was obtained, and the diagnosis was confirmed by performing an upper GI endoscopy. In cases where endoscopy was performed first, definitive diagnosis was made in only one case, and the other cases were confirmed by the CT scan. In some cases, tip attachments, converting to long endoscopes, and marking clips were found useful. CONCLUSIONS: In patients who have undergone intervention to manage an aortic pathology and have episodes of upper gastrointestinal bleeding, ADF cannot be definitively diagnosed with only one investigation. In addition, when performing upper GI endoscopy in cases where an ADF is suspected, tip attachment, converting to a long endoscope, and using marking clips can be helpful.

One-Step Biotinylation of Cellulose Paper by Polymer Coating to Prepare a Paper-Based Analytical Device.

Cellulose paper has strong potential as an analytical platform owing to its unique characteristics. In the present study, we investigated a procedure for functionalizing the surface of cellulose paper by dip-coating a mixture of a functional polymer and a perfluoroalkylated surfactant (surfactant 1). The functional polymer comprised a mixture of methyl methacrylate and poly(ethylene glycol) methacrylate monomers. The monomer ratio in the functional polymer affected the hydrophilicity and water absorbance of the cellulose paper after dip-coating. Furthermore, the presence of surfactant 1 during dip-coating promoted the surface segregation of poly(ethylene glycol) (PEG) moieties in the polymer, which enhanced the hydrophilicity, prevented nonspecific protein adsorption, and maintained the water absorbance of the dip-coated cellulose paper. Dip-coating with another functional polymer containing biotin groups produced a cellulose paper with a biotin-decorated surface in a one-step procedure. The displayed biotin groups immobilized avidin on the surface, and the PEG moieties in the polymer prevented nonspecific protein adsorption. We then immobilized a thrombin-binding DNA aptamer on the avidin-immobilized cellulose paper to prepare a paper-based analytical device. It is possible to visualize thrombin in model solutions and serum using the paper-based analytical device.

Surface Modification and Adhesion Mechanism of Isotactic Polypropylene with Low-Energy Electron-Beam Treatments.

Recently, smaller-size electron-beam (EB) accelerators have offered EB irradiation in laboratory systems. Therefore, polymer surface treatments with low-energy EB have been developed in the past years. For high adhesion strength, low-energy EB treatment is also a promising method in comparison to plasma surface treatment. In the plasma treatment, the mechanism of the effect on the adhesion properties has been proved and the excess treatments led to the formation of a weak boundary layer and reduction of adhesion strength. In contrast, the low-energy EB possesses high penetration ability. In this work, we focused on the surface treatments of isotactic polypropylene (it.PP) with low-energy EB irradiation for adhesion. The dependence of adhesion strength on the absorbed dose of electron beam was evaluated, and the mechanism of electron beam on the adhesion properties was investigated from various perspectives of surface properties and morphology. Compared to that of plasma-treated it.PP, the adhesion strength of it.PP with electron-beam irradiation increased drastically. We proved that the radical was generated in the substrates after electron-beam treatments and would form covalent bonds between adhesives and substrates, which achieved higher adhesion than plasma treatments. In addition, the electron beam reached effectively a deep region from the top surface of the substrates and provided larger adhesion strength.

Formal preparation of regioregular and alternating thiophene-thiophene copolymers bearing different substituents.

Differently substituted thiophene-thiophene-alternating copolymers were formally synthesized employing a halo-bithiophene as a monomer. Nickel-catalyzed polymerization of bithiophene with substituents at the 3-position, including alkyl-, fluoroalkyl-, or oligosiloxane-containing groups, afforded the corresponding copolymers in good to excellent yield. The solubility test in organic solvents was performed to reveal that several copolymers showed a superior solubility. X-ray diffraction analysis of the thin film of the alternating copolymers composed of methyl and branched oligosiloxane substituents was also performed, and the results suggested the formation of a dual-layered film structure.

Surface Modification of Poly(ether ether ketone) through Friedel-Crafts Reaction for High Adhesion Strength.

Poly(ether ether ketone) (PEEK) possesses attractive mechanical and thermal properties but demonstrates poor adhesion. To overcome this disadvantage, in this study, the surface modification of PEEK or PEEK-based carbon-fiber-reinforced thermoplastics (CFRTP) was performed through the Friedel-Crafts reaction and successive epoxidation. Under optimized reaction conditions, surface modification was achieved without surface deterioration, and epoxy groups were introduced. The progress of the Friedel-Crafts reaction and epoxidation was demonstrated by X-ray photoelectron spectroscopy measurements after fluorine labeling through thiol-en reaction and amine addition, respectively. The adhesive strength between CFRTP and epoxy adhesives was increased to 23.5 MPa, and cohesive fracture of epoxy adhesives, rather than interfacial peeling, occurred. In addition, compared with conventional plasma treatment, the durability of the modified surface and thickness of the modified surface layer increased. Therefore, we succeeded in modifying the surface properties through the epoxidation of the PEEK surface.

Controlling Surface Segregation of a Polymer To Display Carboxy Groups on an Outermost Surface Using Perfluoroacyl Groups.

Controlling the surface properties of solid polymers is important for practical applications. We here succeeded in controlling the surface segregation of polymers to display carboxy groups on an outermost surface, which allowed the covalent immobilization of functional molecules via the carboxy groups on a substrate surface. Random methacrylate-based copolymers containing carboxy groups, which were protected with perfluoroacyl (Rf) groups, were dip-coated on acrylic substrate surfaces. X-ray photoelectron spectroscopy and contact-angle measurements revealed that the Rf groups were segregated to the outermost surface of the dip-coated substrates. The Rf groups were removed by hydrolysis of the Rf esters in the copolymers, resulting in the display of carboxy groups on the surface. The quantification of carboxy groups on a surface revealed that the carboxy groups were reactive to a water-soluble solute in an aqueous solution. The surface segregation was affected by the molecular structure of the copolymer used for dip-coating.

Reinforcement Effects from Nanodiamond in Cellulose Nanofibril Films.

Although research on nanopaper structures from cellulose nanofibrils (CNFs) is well established, the mechanical behavior is not well understood, especially not when CNF is combined with hard nanoparticles. Cationic CNF (Q-CNF) was prepared and successfully decorated by anionic nanodiamond (ND) nanoparticles in hydrocolloidal form. The Q-CNF/ND nanocomposites were filtered from a hydrocolloid and dried. Unlike many other carbon nanocomposites, the Q-CNF/ND nanocomposites were optically transparent. Reinforcement effects from the nanodiamond were remarkable, such as Young's modulus (9.8 → 16.6 GPa) and tensile strength (209.5 → 277.5 MPa) at a content of only 1.9% v/v of ND, and the reinforcement mechanisms are discussed. Strong effects on CNF network deformation mechanisms were revealed by loading-unloading experiments. Scratch hardness also increased strongly with increased addition of ND.

Synthesis of Bisdesmosidic Oleanolic Acid Saponins via a Glycosylation-Deprotection Sequence under Continuous Microfluidic/Batch Conditions.

We report the first synthesis of a series of bisdesmosidic oleanolic acid saponins using microflow reactor Comet X-01 via a continuous flow glycosylation-batch deprotection sequence. The main results of this study can be summarized as follows: (1) The microfluidic glycosylation of oleanolic acid at C-28 was achieved in quantitative yield and was applied to the synthesis of six C-28-monoglycosidic saponins. (2) The microfluidic glycosylation of oleanolic acid at C-3 was achieved in good yield without orthoester byproduct formation and was applied to the synthesis of three bisdesmosidic saponins. (3) The continuous synthesis of saponins via a microfluidic glycosylation-batch deprotection sequence was achieved in four steps involving two purifications. Thus, the continuous microfluidic glycosylation-deprotection process is expected to be suitable for the preparation of a library of bisdesmosidic oleanolic acid saponins for in vivo pharmacological studies.

Syntheses and mucosal adjuvant activity of simplified oleanolic acid saponins possessing cinnamoyl ester.

A series of new simplified oleanolic acid saponins with a glycosyl ester moiety at C28, were efficiently prepared. Furthermore, the effect of nasal administration of the synthetic oleanolic acid saponins on the nasal anti-influenza virus antibody titer against secondary nasal inoculation of the influenza split vaccine was examined. The result revealed cinnamoyl saponin as a suitable candidate vaccine adjuvant.

Risk Factors Associated with Cisplatin-Induced Nephrotoxicity in Patients with Advanced Lung Cancer.

Cisplatin (CDDP) combination chemotherapy is widely administered to patients with advanced lung cancer. The dose depends on multiple factors, including whether the tumor is non-small-cell lung cancer (NSCLC) or small-cell lung cancer (SCLC). Although efficacy is limited by cisplatin-induced nephrotoxicity (CIN), little is known about the risk factors for this complication. The aim of this study was to identify the risk factors for CIN in patients with advanced lung cancer, both NSCLC and SCLC. We retrospectively reviewed clinical data for 148 patients who underwent initial chemotherapy including CDDP ≥50 mg/m2 per patient per day for the first course at Kyushu Medical Center between October 2010 and September 2013. All data were collected from the electronic medical record system. Nephrotoxicity was defined as an increase in serum creatinine concentration of at least grade 2 during the first course of CDDP chemotherapy, as described by the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. CIN was observed in nine patients. Univariate analysis revealed that cardiac disease and lower baseline serum albumin (Alb) values conferred a higher risk of nephrotoxicity (p<0.05). The cut-off value of Alb was 3.8 g/dL, calculated by receiver operating characteristics (ROC) curves. Multivariable logistic regression analysis revealed that cardiac disease (odds ratio=11.7; p=0.002) and hypoalbuminemia (odds ratio=6.99 p=0.025 significantly correlated with nephrotoxicity. In conclusion, cardiac disease and low baseline Alb values are possible risk factors for CIN.

Highly water repellent but highly adhesive surface with segregation of poly(ethylene oxide) side chains.

Polymer surfaces were modified using methacrylate terpolymers containing both perfluoroalkyl (Rf) groups and poly(ethylene oxide) (PEO) as side chains in the same molecule. The structure and properties of the modified surfaces were evaluated using X-ray photoelectron spectroscopy and by measuring the dynamic contact angles and 90° peel strength. It was found that not only Rf groups but also PEO side chains were segregated on the surface being against the order of the surface free energy. The terpolymer modified surface is hydrophobic in air because Rf groups are predominant, but it becomes hydrophilic in water because the surface is covered with PEO side chains. This response to the environment is rapid and reversible. The modified surface showed high water repellency because of the surface Rf groups and high adhesive strength because of the side chains.

Quantification of Amino Groups on Solid Surfaces Using Cleavable Fluorescent Compounds.

We quantified amino groups displayed on inorganic and organic surfaces in aqueous solution using different types of cleavable fluorescent compounds and an aldehyde dye. The cleavable fluorescent compounds were designed to bind covalently to amino groups and then liberated under specific conditions. Among the investigated materials, cleavable coumarin was most appropriate for the quantification of amino groups on silica and resin surfaces. The developed method can measure small amounts (∼pmol/cm(2)) of amino groups on a flat polymeric surface, detecting only amino groups that are exposed to aqueous solution and available for surface immobilization of ligands and biomolecules.

Surfactant-induced polymer segregation to produce antifouling surfaces via dip-coating with an amphiphilic polymer.

We propose a rational strategy to control the surface segregation of an amphiphilic copolymer in its dip-coating with a low-molecular-weight surfactant. We synthesized a water-insoluble methacrylate-based copolymer containing oligo(ethylene glycol) (OEG) (copolymer 1) and a perfluoroalkylated surfactant (surfactant 1) containing OEG. The dip-coating of copolymer 1 with surfactant 1 resulted in the segregation of surfactant 1 on the top surface of the dip-coated layer due to the high hydrophobicity of its perfluoroalkyl group. OEG moieties of surfactant 1 were accompanied by those of copolymer 1 in its segregation, allowing the OEG moieties of copolymer 1 to be located just below the top surface of the dip-coated layer. The removal of surfactant 1 produced the surface covered by the OEG moieties of the copolymer that exhibited antifouling properties. Using this strategy, we also succeeded in the introduction of carboxy groups on the dip-coated surface and demonstrated that the carboxy groups were available for the immobilization of functional molecules on the surface.

[Efficacy and safety of transdermal fentanyl patches for opioid initiation in patients with gastrointestinal obstruction].

The transdermal fentanyl patch (TDF) can be used when switching from other opioids; therefore, little is known about the efficacy and safety of TDF patches applied for opioid initiation. However, TDF patches have been applied for opioid initiation in gastrointestinal cancer patients with gastrointestinal obstruction. In this study, we retrospectively investigated 12 gastrointestinal cancer patients to evaluate the efficacy and frequency of adverse effects of TDF patches compared to oral oxycodone (OXY) for opioid initiation. The frequency of adverse effects such as nausea, somnolence, and constipation in the TDF patch group was 25%, 41.7%, and 8.3%, respectively. No severe adverse effects were observed, and there was no significant difference between the TDF patch and OXY groups. Moreover, according to the numerical pain rating scale(ranging from 0 [no pain] to 10 [worst possible pain]), the pain intensity in the TDF patch group decreased from 5.42 on the first day to 3.33 after 3 days (p=0.0377), and 2.67 after 7 days (p=0.0089), with no significant difference between groups. Our study results suggest that TDF patches applied for opioid initiation may be useful for gastrointestinal cancer patients with gastrointestinal obstruction.

Systemic AL amyloidosis with multiple submucosal hematomas of the colon: a case report and literature review.

Amyloid light-chain (AL) amyloidosis rarely causes colorectal submucosal hematoma. A 76-year-old man presented with a complaint of bloody stool. An initial colonoscopy revealed ulcerative lesions in the descending colon, leading to a diagnosis of ischemic colitis. One month later, he presented with cardiac failure, suspected cardiac amyloidosis, and underwent a second colonoscopy. Although it revealed multiple ulcerative lesions from the ascending to transverse colon, biopsy samples did not confirm amyloid deposition. He underwent a third colonoscopy 3 weeks later due to recurrent bloody stool. It showed multiple submucosal hematomas from the ascending to descending colon concomitant with ulcerative lesions in the descending colon and multiple elevated lesions in the sigmoid colon. Biopsy samples confirmed amyloid deposition. Using a systemic search, multiple myeloma with AL amyloidosis was diagnosed. Colorectal submucosal or intramural hematomas are conditions usually encountered in trauma, antithrombotic use, or coagulation disorders. Based on our review of the literatures, we identified several differences between colorectal intramural hematoma caused by amyloidosis and those caused by other etiologies. We believe that amyloidosis should be considered when relatively small and multiple colorectal hematomas, not restricted to the sigmoid colon, and with concomitant findings of erosions and ulcers, are observed.

Giant Brunner's gland hyperplasia of the duodenum successfully resected en bloc by endoscopic mucosal resection: A case report.

BACKGROUND: Duodenal Brunner's gland hyperplasia (BGH) is a therapeutic target when complications such as bleeding or gastrointestinal obstruction occur or when malignancy cannot be ruled out. Herein, we present a case of large BGH treated with endoscopic mucosal resection (EMR). CASE SUMMARY: An 83-year-old woman presented at our hospital with dizziness. Blood tests revealed severe anemia, esophagogastroduodenoscopy showed a 6.5 cm lesion protruding from the anterior wall of the duodenal bulb, and biopsy revealed the presence of glandular epithelium. Endoscopic ultrasonography (EUS) demonstrated relatively high echogenicity with a cystic component. The muscularis propria was slightly elevated at the base of the lesion. EMR was performed without complications. The formalin-fixed lesion size was 6 cm × 3.5 cm × 3 cm, showing nodular proliferation of non-dysplastic Brunner's glands compartmentalized by fibrous septa, confirming the diagnosis of BGH. Reports of EMR or hot snare polypectomy are rare for duodenal BGH > 6 cm. In this case, the choice of EMR was made by obtaining information on the base of the lesion as well as on the internal characteristics through EUS. CONCLUSION: Large duodenal lesions with good endoscopic maneuverability and no evident muscular layer involvement on EUS may be resectable via EMR.