Oxalates as Activating Groups for Alcohols in Visible Light Photoredox Catalysis: Formation of Quaternary Centers by Redox-Neutral Fragment Coupling.

Alkyl oxalates are new bench-stable alcohol-activating groups for radical generation under visible light photoredox conditions. Using these precursors, the first net redox-neutral coupling of tertiary and secondary alcohols with electron-deficient alkenes is achieved

The Efficacy of Pressure Ulcer Treatment With Cathodal and Cathodal-Anodal High-Voltage Monophasic Pulsed Current: A Prospective, Randomized, Controlled Clinical Trial

Background. Studies show that anode and cathode electrical stimulation (ES) promotes the healing of wounds, but specific protocols for both electrodes are not available. Objective. To compare the effectiveness of cathodal versus cathodal+anodal ES in the treatment of Category II-IV pressure ulcers (PrUs). Design. Prospective, randomized, controlled, clinical study. Setting. Three nursing and care centers. Patients. Sixty-three participants with PrUs were randomly formed into a cathodal ES group (CG: N = 23; mean age of 79.35; SD 8.48), a cathodal+anodal ES group (CAG: N = 20; mean age of 79.65; SD 11.44) and a placebo ES group (PG: N = 20; mean age of 76.75; SD 12.24). Intervention. All patients were treated with standard wound care and high-voltage monophasic pulsed current (HVMPC; twin-peak impulses; 154 μs; 100 pps; 0.25 A; 250 μC/s) for 50 minutes per day, 5 times a week, for 6 weeks. The CG, CAG, and PG received, respectively, cathodal, cathodal+anodal, and sham ES through electrodes placed on a moist gauze pad. The treatment electrode was placed on the wound, and the return electrode was positioned on healthy skin at least 20 cm from the PrU. Measurements. Measurements were made at baseline, and after each of the 6 weeks of treatment. Primary outcome was percentage wound surface area reduction at week 6. Results. Wound surface area decreased in the CG by 82.34% (95% confidence interval [CI] 70.06-94.63) and in the CAG by 70.77% (95% CI 53.51-88.04). These reductions were significantly greater than in the PG (40.53%; 95% CI 23.60-57.46). The CG and CAG were not statistically significantly different regarding treatment results. Limitations. The time of treatment proved insufficient for PrUs to close. Conclusions. Cathodal and cathodal+anodal HVMPC similarly reduced the area of Category II-IV PrU

Synthesis of toxyloxanthone B

A synthesis of the naturally occurring xanthone toxyloxanthone B is described, in which the key step is the regioselective addition of a methyl salicylate to a substituted benzyne followed by cyclization of the intermediate aryl anion to form the xanthone, the regiochemistry of the aryne addition being confirmed by X-ray crystallography. Subsequent introduction of the pyran ring by [3,3]-rearrangement and deprotection completed the synthesi

Evaluation of the Healing Progress of Pressure Ulcers Treated with Cathodal High-Voltage Monophasic Pulsed Current: Results of a Prospective, Double-blind, Randomized Clinical Trial

OBJECTIVE: To investigate the effectiveness of high-voltage monophasic pulsed current (HVMPC) as an adjunct to a standard wound care for the treatment of Stage II and III pressure ulcers (PrUs). DESIGN: Prospective, randomized, double-blind, controlled clinical study. SETTING: Two nursing and care centers. PATIENTS: Patients with PrUs that did not respond to previous treatment for at least 4 weeks were randomly assigned to the electrical stimulation (ES) group (25 patients; mean age of 79.92 ± 8.50 years; mean wound surface area [WSA] of 10.58 ± 10.57 cm2) or to the control group (24 patients; mean age of 76.33 ± 12.74 years; mean WSA of 9.71 ± 6.70 cm2). INTERVENTIONS: Both the ES and control groups received standard wound care and respectively, cathodal HVMPC (154 microseconds; 100 pulses per second; 0.24 A; 250 μ/s) applied continuously for 50 minutes once a day, 5 times a week, or sham HVMPC. MAIN OUTCOME: Percentage area reduction over 6 weeks of intervention. MAIN RESULTS: In the ES group, there was a statistically significant decrease in WSA after 1 week of treatment (35% ± 30.5%) compared with 17.07% ± 34.13% in the control group (P = .032). After treatment, at week 6, percentage area reduction in the ES group was 80.31% ± 29.02% versus 54.65% ± 42.65% in the control group (P = .046). CONCLUSIONS: Cathodal HVMPC reduces the WSA of Stage II and III PrUs. The results are consistent with the results of other researchers who used HVMPC to treat PrUs

Oxalates as Activating Groups for Alcohols in Visible Light Photoredox Catalysis: Formation of Quaternary Centers by Redox-Neutral Fragment Coupling

Alkyl oxalates are new bench-stable alcohol-activating groups for radical generation under visible light photoredox conditions. Using these precursors, the first net redox-neutral coupling of tertiary and secondary alcohols with electron-deficient alkenes is achieved

Oxalates as Activating Groups for Alcohols in Visible Light Photoredox Catalysis: Formation of Quaternary Centers by Redox-Neutral Fragment Coupling.

Alkyl oxalates are new bench-stable alcohol-activating groups for radical generation under visible light photoredox conditions. Using these precursors, the first net redox-neutral coupling of tertiary and secondary alcohols with electron-deficient alkenes is achieved

Force feedback control system dedicated for Robin Heart Pelikan

Przedmiotem niniejszej pracy jest badanie systemów sterowania robota Robin Heart PVA (ang. Port Vision Able) z zastosowaniem specjalnych mikroczujników siły 3D MEMS. Postawiono trzy różne sposoby wykorzystania opracowywanych czujników: (1) jako czujnik siły wykorzystany jako mikrodżojstik zintegrowany w rękojeścią narzędzia endoskopowego, aby łatwo kontrolować ruch robota wizyjnego podczas pracy chirurga; (2) jako czujnik siły wewnątrz szczęki narzędzia endoskopowego dla dostarczenia informacji zwrotnej do operatora-chirurga, mierząc siłę chwytu; (3) jako czujnik wielowymiarowy dotyku na końcu narzędzia chirurgicznego, co ułatwia badanie palpacyjne do diagnostyki tkanek podczas pracy. Artykuł ten jest studium wykonalności w zakresie proponowanych zastosowań. Model sterowania robota przy użyciu prototypowego czujnika siły 3D został pomyślnie przetestowany w badaniach funkcjonalnych robota. Wstępne badania sensorów wykazały ich przydatność dla sterowania robotem ze sprzężeniem siłowym, aby ocenić stan tkanek oraz do oceny siły docisku chirurgicznego chwytaka.The aim of this work is to investigate the control systems of Robin Heart PVA (Port Vision Able) using special 3D MEMS force microsensors. Three different functions are targeted: (1) micro-joystick actuator to be integrated in the hilt of the laparoscope to easily control robotic movement during operation; (2) force sensor inside the laparoscopic jaw to provide feedback to the surgeon by measuring the grasping strength; (3) 3D force/tactile sensor which facilitates palpation for tissue diagnostics during operation. This paper is a feasibility study regarding these proposed applications. A model of the robot controller using a prototype 3D sensor force has been successfully tested during the study of functional robot. Pre-studies of prototype sensors have demonstrated their usefulness in robot force feedback system to assess the state of tissue and to assess the clamping force the grasper surgical system

Toward the Total Synthesis of Hygrocin B and Divergolide C: Construction of the Naphthoquinone–Azepinone Core

A highly regioselective Diels–Alder approach toward the bioactive natural products hygrocin B and divergolide C is presented. The route uses an unusual benzoquinone–azepinone dienophile prepared in 8 steps from ethyl 8-methoxy-1-naphthoate, by a route which includes, as key steps, a Birch alkylation and a Beckmann rearrangement of a tetralone oxime, both of which are demonstrated on multigram scale. The naphthoquinone–azepinone core is suitably functionalized for addition of the ansa-chain, found in the natural products